Abstract
Multiple sclerosis (MS) is a extraordinarily prevalent demyelinating autoimmune state of affairs; the mechanisms regulating its severity and growth are unclear. The IL-17-producing Th17 subset of T cells has been broadly implicated in MS and inside the mouse model, experimental autoimmune encephalomyelitis (EAE). However, the differentiation and regulation of Th17 cells all through EAE keep incompletely understood. Although proof is mounting that the antimicrobial peptide cathelicidin profoundly impacts early T cell differentiation, no analysis have checked out its perform in longer-term T cell responses. Now, we report that cathelicidin drives excessive EAE sickness. It is launched from neutrophils, microglia, and endothelial cells all by means of sickness; its interaction with T cells potentiates Th17 differentiation in lymph nodes and Th17 to exTh17 plasticity and IFN-γ manufacturing inside the spinal twine. As a consequence, mice lacking cathelicidin are protected in opposition to excessive EAE. In addition, we current that cathelicidin is produced by the an identical cell kinds inside the energetic thoughts lesions in human MS sickness. We recommend that cathelicidin publicity ends in extraordinarily activated, cytokine-producing T cells, which drive autoimmunity; this is usually a mechanism by the use of which neutrophils amplify irritation inside the central nervous system.
Citation: Smith KJ, Minns D, McHugh BJ, Holloway RK, O’Connor R, Williams A, et al. (2022) The antimicrobial peptide cathelicidin drives enchancment of experimental autoimmune encephalomyelitis in mice by affecting Th17 differentiation. PLoS Biol 20(8):
e3001554.
https://doi.org/10.1371/journal.pbio.3001554
Academic Editor: Takeshi Tsubata, Tokyo Medical and Dental University Medical Research Institute, JAPAN
Received: January 5, 2022; Accepted: July 21, 2022; Published: August 26, 2022
Copyright: © 2022 Smith et al. This is an open entry article distributed beneath the phrases of the Creative Commons Attribution License, which permits unrestricted use, distribution, and replica in any medium, supplied the distinctive creator and provide are credited.
Data Availability: All associated information are contained inside the paper and supporting information recordsdata. The Nanostring information will be discovered from the GEO database, accession amount GSE188655. All completely different information will be discovered at Figshare, DOI 10.6084/m9.figshare.20310363.
Funding: This work was funded by a Royal Society Dorothy Hodgkin Fellowship (DH150175) and two Royal Society Fellows’ Enhancement Awards (RGFEA180049 and RGFEA201009) to EGF, an Action Medical Research grant to DJD (GN2703) and by Medical Research Council Senior Fellowships to DJD (G1002046) and VEM (V031260/1). Royal Society website online – https://royalsociety.org/; Action Medical Research – https://action.org.uk/; MRC – https://mrc.ukri.org/. The funders had no perform in analysis design, information assortment and analysis, dedication to publish, or preparation of the manuscript.
Competing pursuits: The authors have declared that no competing pursuits exist.
Abbreviations:
BBB,
blood–thoughts barrier; CFA,
full Freund’s adjuvant; CNS,
central nervous system; EAE,
experimental autoimmune encephalomyelitis; HE,
haematoxylin–eosin; KO,
knockout; MOG,
myelin oligodendrocyte glycoprotein; MS,
plenty of sclerosis; NE,
neutrophil elastase; PFA,
paraformaldehyde; RT,
room temperature; WT,
wild-type
Introduction
In this enterprise, we examined the differentiation of cytokine-producing T cells all through plenty of sclerosis (MS). MS is a demyelinating, neurodegenerative sickness of the central nervous system (CNS) [1]. Through the modelling of MS using experimental autoimmune encephalomyelitis (EAE), we now understand that T cells play a central perform in driving this sickness [2–8]. However, the priming of pathogenic T cells all through MS is difficult and stays to be not completely understood. In specific, how completely different innate and adaptive immune cells affect longer-term T cell carry out inside the CNS is unclear.
Like in several autoinflammatory circumstances [9], the Th17 subset of cells is very important for driving sickness in MS and EAE [10–14], by the use of their means to cross into the CNS following priming inside the lymph nodes [15–18]; as quickly as there, Th17 cells moreover drive sickness by the use of contributing to blood–thoughts barrier (BBB) breakdown by attracting MMP-releasing neutrophils to the placement [19–22].
Neutrophils have a dynamic relationship with T cells and it is successfully understood that they’re going to have an effect on T cell activation and migration [23,24]. There is now substantial proof that neutrophils are important and pathogenic in EAE and MS. Neutrophil populations broaden all through every illnesses and switch into the CNS [25–27]. The peripheral neutrophil populations are moreover dysregulated, with an activated phenotype [28]. Depletion of neutrophils abrogates EAE sickness [4,29,30]. The actual mechanisms by the use of which neutrophils worsen EAE and improve severity of autoimmune circumstances have not, however, been described; and whereas Th17 cell affect on neutrophils inside the CNS is believed [4], the reverse—the affect of neutrophils on Th17 cell differentiation and survival—stays to be unclear.
We have beforehand confirmed that neutrophil launch of the antimicrobial host defence peptide cathelicidin, which occurs all through degranulation and launch of extracellular traps, potentiates Th17 differentiation in vitro and in fashions of acute irritation [31]. However, its perform in longer-term irritation or in irritation of the CNS simply is not acknowledged.
We now reveal that cathelicidin simply is not expressed inside the healthful murine CNS or secondary lymphoid organs nevertheless is strongly produced all through EAE and inside the energetic demyelinated thoughts lesions of victims with MS. Cathelicidin manufacturing performs a elementary perform in sickness pathogenesis. Mice lacking the peptide have lowered incidence of EAE as T cell manufacturing of proinflammatory cytokines is lowered. We recommend that cathelicidin is essential for the occasion of pathogenic longer-term Th17 responses in inflammatory sickness.
Results
Cathelicidin is expressed by plenty of cell kinds in lymphoid organs and the central nervous system
Cathelicidin is launched in lymph nodes all through acute irritation, however whether or not or not this occurs all through longer-term sterile irritation is unknown. To assess this, we used the persistent inflammatory model, EAE, a model of immune-mediated demyelination in MS. We induced sickness with the myelin oligodendrocyte glycoprotein (MOG) peptide MOG35–55 in wild-type (WT) C57BL/6JOlaHsD mice, following the same old protocol, and tracked indicators of sickness. Mice confirmed fixed onset of sickness (S1A Fig) with suggest day of symptom presentation being day 12 and median ranking being 2 (full lack of tail mobility, altered gait and lack of stability). Inflammation and immune cell infiltration inside the spinal twine elevated consistently (S1B Fig), and T cells had been detected inside the spinal twine by immunohistochemistry from day 7 post-immunisation. The numbers of the total T cell inhabitants (S1C and S1D Fig) and IL-17 producers (S1E Fig) peaked at day 14, which will also be the peak of indicators, in settlement with beforehand revealed information [13,32].
As we hypothesised that publicity of these T cells to cathelicidin would promote their differentiation into Th17 cells and improve their pathogenicity, the 1st step was to find out whether or not or not and when cathelicidin publicity occurred, as a result of it has not beforehand been characterised all by means of a persistent inflammatory in vivo model. We because of this reality examined the inguinal lymph node, which drains the injection website online, and the spinal twine, the placement of irritation.
In common state, mice cathelicidin was not detected in lymph nodes (Fig 1A and 1B) or spinal twine (Fig 1C and 1D). However, as a result of the immune response to immunisation developed, rising portions of cathelicidin had been detected. We well-known low-level detection inside the inguinal lymph nodes as early as day 4 post-immunisation and it elevated with time, with extreme ranges of detection on day 14 (peak of sickness) (Fig 1B).
Fig 1. The antimicrobial peptide cathelicidin is produced inside the CNS all through EAE.
EAE was induced in WT C57BL/6J mice on day 0 and mice seen for 28 days. Throughout the experiment, mice had been humanely culled, perfused with 4% paraformaldehyde and cathelicidin-producing cells had been quantified in (A, B) draining inguinal lymph nodes and (C, D) spinal cords. Statistical assessments used: B—one-way ANOVA, D–two-tailed t check out evaluating day 14 to day 0. N values: A–images marketing consultant of 5–8 sections from 3 mice; B—3–5 sections from 3 mice; C–images marketing consultant of three–4 mice; D– 13–42 sections analysed from 4–6 mice. Data obtainable at 10.6084/m9.figshare.20310363. Cath, cathelicidin; CNS, central nervous system; EAE, experimental autoimmune encephalomyelitis; LN, lymph node; WT, wild-type.
In the spinal twine, cathelicidin was detected from day 4 post-immunisation, per earlier observations that neutrophils cross into the CNS very early after immunisation [4,25,30,33]. While cathelicidin-positive cells appeared by means of the preclinical stage of the sickness, they’d been significantly elevated by means of the acute phase (Fig 1C and 1D).
Having established that cathelicidin is expressed inside the spinal twine, we subsequent sought to seek out out which cells had been releasing it. Cathelicidin is considered inducible in a variety of cell kinds. It is predominantly produced by neutrophils and launched from the secondary granules by degranulation [34,35]; moreover it’s present on extracellular traps [36]. However, moreover it’s expressed by completely different cells, along with T cells [37,38], adipocytes [39], epithelium [40–42], and mast cells [43] in mice and folks. In the inguinal lymph node, cathelicidin was produced almost completely by neutrophils (Fig 2A) with proof of some having been launched, as a result of it was not associated to cells. This agrees with our earlier work demonstrating that cathelicidin inside the lymph nodes, following inoculation with heat-killed Salmonella typhimurium, is launched from neutrophils [31]. However, cathelicidin inside the murine spinal twine was detected in a variety of cell kinds. The majority of cathelicidin was associated to Ly6G+ neutrophils (roughly 70% of expression was from neutrophils on day 14) (Fig 2B and 2C), nevertheless some expression was well-known in CD31+ endothelial cells (roughly 15% of expression) and Iba1+ microglia/macrophages (roughly 15% of expression).
Fig 2. Cathelicidin is produced by plenty of cell kinds inside the CNS all through EAE.
EAE was induced in WT C57BL/6J mice on day 0 and mice seen for 28 days. Throughout the experiment, mice had been humanely culled, perfused with 4% paraformaldehyde and cathelicidin-producing cells had been quantified. On days 7 and 14 post-immunisation, co-staining was carried out to seek out out manufacturing of cathelicidin by Ly6G+ neutrophils, F480+/Iba1+ microglia/macrophages, and CD31+ endothelial cells–(A) reveals the cell sort associated to cathelicidin inside the draining inguinal lymph node (B) occasion images from spinal twine on day 14 and contribution of each cell sort to common cathelicidin manufacturing inside the (C) spinal twine was selected day 14 post-immunisation. Analysis of revealed sequencing databases of murine microglia, astrocytes, oligodendrocytes, and neurons had been carried out. Databases had been each accessed from supplementary data of the associated papers or seemed for in NCBI GEO Datasets. The search phrases had been as follows: “cell type” AND “rna seq” AND “mouse” NOT “iPSC.” (D) All datasets all through common state had been analysed for expression of HDPs. The heatmap reveals the share of databases analysed that expressed the named HDP. Blue signifies a extreme proportion of databases had optimistic expression, and white signifies a low proportion of databases had optimistic HDP expression. (E) The proportion of microglia databases analysed that had optimistic Camp expression in a number of circumstances—steady-state, hurt, and ageing. The amount above the bar represents the number of databases analysed. Data confirmed are explicit individual information elements with line at median. N values: A– 3–5 sections from 3 mice; B and C– 13–18 sections from 4 mice; D–microglia– 13, neurons– 16, oligodendrocytes– 8, and astrocytes– 8; E–common state– 5, hurt– 4, ageing– 2. (Dataset data listed in S1 and S2 Tables). Data obtainable at 10.6084/m9.figshare.20310363. Cath, cathelicidin; CNS, central nervous system; EAE, experimental autoimmune encephalomyelitis; HDP, host-defence peptide; sec, secondary; WT, wild-type.
We had been involved about confirming these information by analyzing mRNA expression in CNS cells; it is potential that the seen cathelicidin manufacturing in Fig 2B and 2C was a outcomes of its launch by completely different cells and subsequent uptake by the CNS-resident cells similar to microglia. To research whether or not or not CNS cells had been actively transcribing Camp, we analysed a sequence of revealed gene expression datasets of murine neuron, astrocyte, oligodendrocyte, and microglia cells (all datasets listed in S1 and S2 Tables). We analysed these cell datasets for the presence of quite a lot of HDP (Fig 2D) and positioned cathelicidin was primarily essentially the most expressed HDP inside the CNS. It was found to be transcribed in 92.3% of microglial datasets analysed, 37.5% of neuronal datasets, and 37.5% of astrocyte datasets. In distinction, it was not found to be transcribed in oligodendrocytes. Other HDP weren’t broadly expressed (Fig 2D). The microglia outcomes had been attention-grabbing and agreed with our comment that cathelicidin was produced by these cells all through EAE. Further examination of the microglial datasets demonstrated expression of cathelicidin in common state (80% of datasets), hurt similar to spinal twine ligation (100%), and in aged mice (100%) (Fig 2E), suggesting a low stage of regular manufacturing.
Together, these information reveal that cathelicidin is broadly produced all through EAE, by neutrophils, and by resident CNS cells and that it persists long term over the course of sickness, with expression peaking at maximal sickness severity.
Cathelicidin is expressed all through human plenty of sclerosis sickness
Next, we wished to seek out out whether or not or not cathelicidin will also be expressed in human MS. To accomplish that, we analysed postmortem thoughts tissue from 7 victims from the UK Multiple Sclerosis Tissue Bank (affected individual data listed in S3 Table). Expression of cathelicidin was well-known, surprisingly, in administration thoughts tissue along with in MS thoughts tissue (Fig 3A and 3B). We well-known that this expression was localised and subsequent quantified cathelicidin in separate lesions, using the International Classification of Neurological Diseases ideas. Lesions develop from normal-appearing white matter. Active lesions are characterised by an influx of immune cells, activated resident microglia, and demyelination. Lesions may bear energetic remyelination nevertheless can also turn into chronically inactive, a state of affairs during which there’s intensive demyelination and few immune cells present. Moreover, lesions can turn into chronically energetic with a carefully demyelinated core and activated glial cells on the rim [44–46]. We well-known an enormous improve in cathelicidin expression inside the energetic demyelinated lesions (Fig 3C). In distinction, the persistent energetic, persistent inactive, and remyelinating lesions did not have elevated cathelicidin as compared with administration tissue (Fig 3C).
Fig 3. Cathelicidin is produced inside the healthful and contaminated human thoughts.
Postmortem thoughts sections had been obtained from victims who died of MS and administration victims with no neurological sickness. (A-C) Cathelicidin (Cath.) manufacturing was quantified using immunofluorescent imaging. Grey arrowheads level out cathelicidin inside blood vessels, and white arrowheads level out cathelicidin exterior vessels. Data confirmed are (B and C) explicit individual information elements with line at median. Statistical check out used: in (C)–two-tailed t check out. N values: B and C– 7 victims in MS group and three victims in administration group, each information stage represents an space of the thoughts analysed. Images in (A) are marketing consultant of on the very least 3 victims. Patient data is listed in S3 Table. Data obtainable at 10.6084/m9.figshare.20310363. cath, cathelicidin; MS, plenty of sclerosis.
In the energetic lesions, the an identical cell kinds co-localised with human cathelicidin as we had seen in EAE—particularly neutrophils (neutrophil elastase, NE+), microglia/macrophages (CD68+), and endothelial cells (CD31+) (Fig 4A and 4B). Quantification of energetic lesions was carried out to find out the proportion of cathelicidin contributed by each cell sort; the pattern in these lesions was roughly very similar to murine samples, with the overwhelming majority of the cathelicidin coming from neutrophils and a substantial minority from endothelial cells and microglia/macrophages.
Fig 4. Cathelicidin is produced by plenty of cell kinds inside the human CNS.
Postmortem thoughts sections had been obtained from victims who died of MS and administration victims with no neurological sickness. (A-C) Cathelicidin (Cath.) manufacturing was quantified using immunofluorescent imaging. (A) Co-staining was carried out to seek out out manufacturing of cathelicidin by neutrophil elastase (NE)+ neutrophils, CD68+ microglia/macrophages, or CD31+ endothelial cells. (B) Contribution of each cell sort to common cathelicidin manufacturing was determined inside the energetic lesions. (C) Published RNA sequencing human databases had been analysed for HDP expression. Databases had been each accessed from supplementary data of the associated papers or seemed for in NCBI GEO Datasets. The search phrases had been: “cell type” AND “rna seq” AND “human” NOT “iPSC.” A heatmap displaying HDP expression as a proportion of databases analysed is confirmed. Data confirmed in B are explicit individual information elements with line at median. N values: A and B– 7 victims in MS group and three victims in administration group, each information stage represents an space of the thoughts analysed; C– 3 datasets for neurons, 2 for astrocytes, 5 for microglia, and 1 for oligodendrocytes (dataset data listed in S4 Table). Data obtainable at 10.6084/m9.figshare.20310363. cath, cathelicidin; CNS, central nervous system; HDP, host-defence peptide; MS, plenty of sclerosis; NE, neutrophil elastase; sec, secondary.
Again, we downloaded revealed RNA sequencing information from experiments carried out on human CNS-resident cells (datasets used listed in S4 Table) in an effort to affirm that cathelicidin is produced by these cells and by no means merely taken up by them. We found that cathelicidin is produced by microglia and neurons, as inside the murine datasets (Fig 4C) nevertheless not in oligodendrocytes or human astrocytes. In distinction to mice, cathelicidin was not the highest-expressed HDP inside the human CNS, with hepcidin being broadly produced as successfully. However, the pattern of expression well-known in these datasets matched what we had seen on the protein stage. Together, these information current that cathelicidin is expressed by a variety of cell kinds inside the human and murine CNSs all through persistent neuroinflammation.
Cathelicidin promotes excessive sickness in EAE
Next, we examined whether or not or not expression of cathelicidin is required for sickness, by inducing EAE in mice lacking cathelicidin (Camp−/−, knockout, KO), first produced in [47]. Observation of medical indicators of illness demonstrated that KO mice consistently confirmed significantly attenuated sickness as compared with WT mice (Fig 5A and 5B).
Fig 5. Mice lacking cathelicidin are proof in opposition to EAE sickness.
EAE was induced in WT C57BL/6J, cathelicidin KO (Camp KO) mice and LysMCre conditional KO mice on day 0. (A) Clinical indicators of illness had been well-known all by means of the experiment and (B) space beneath the curve calculated for each explicit individual experiment. (C-E) Conditional KO LysMCre mice lacking cathelicidin in myeloid-lineage cells had been generated (see S2 Fig) and (C) immunofluorescence carried out to substantiate microglia and neutrophils lacked cathelicidin. (D) WT mice had been culled on day 14 post-immunisation and spinal twine isolated. Spinal twine cross-sections had been co-stained for neuronal marker NeuN (inexperienced) and cathelicidin (magenta), which confirmed that neurons did not co-localise with cathelicidin inside the spinal twine. (E, F) Clinical indicators of sickness had been tracked in conditional KO mice. Data confirmed are (A, E) suggest and regular error. N values: A—WT 85, Camp−/− 71; E—WT 85, Camp−/− 71, LysMCre 8. Images in C are marketing consultant of three mice. Statistical assessments used: A and E–one-way ANOVA, B–paired two-tailed t check out. Data obtainable at 10.6084/m9.figshare.20310363. Cath, cathelicidin; EAE, experimental autoimmune encephalomyelitis; KO, knockout; WT, wild-type.
Give the plenty of cell kinds acknowledged to have the ability to expressing cathelicidin, notably inside the context of irritation, we wanted to start to stipulate the necessary factor cellular compartment for cathelicidin manufacturing affecting EAE sickness severity, so generated a model new conditional cathelicidin KO mouse. This LysMCre mouse lacks cathelicidin in myeloid-lineage cells (expertise described in S2 Fig). This mouse had no cathelicidin in microglia or neutrophils (Fig 5C). LysM can also be seen in neurons [48], nevertheless no cathelicidin was seen to be produced by WT neuronal cells in our system (Fig 5D). Observation of medical indicators of illness over time (Fig 5E) and incidence of sickness (Fig 5F) confirmed the conditional KO mice phenocopied the total KO animals and had attenuated incidence of sickness, demonstrating that myeloid cell manufacturing of cathelicidin is sufficient for full sickness penetrance and because of this undeniable fact that the well-known endothelial cell manufacturing simply is not necessary for enchancment of sickness.
Cathelicidin would not affect cell infiltration to the spinal twine nevertheless will improve T cell activation
Having confirmed that cathelicidin is crucial for EAE enchancment, we subsequent examined its mechanism of movement. We have beforehand demonstrated that cathelicidin induced survival of T cell subsets [31] and others have confirmed it to be a chemoattractant for T cells [49]. As T cells drive pathology in EAE [16,18,50–53], we because of this reality hypothesised that fewer T cells could possibly be present inside the spinal twine of KO mice and that this was the explanation for the lowered sickness severity. To check out this, we carried out a full flow into cytometric phenotyping of spinal twine immune cells over time in every WT and KO mice (gating approach confirmed in S3 Fig). To our shock, there have been no observable variations in leukocyte infiltration—along with T cell subsets—between WT and KO mice by means of the EAE timecourse (Fig 6A and 6B). In addition, the relative proportions of assorted subsets of immune cells detected inside the spinal twine weren’t significantly completely completely different between the genotypes (Fig 6C and 6D). To extra affirm these findings, we carried out immunofluorescent staining for CD3+ T cells in WT and KO spinal twine and positioned no variations in amount or location on day 14 post-immunisation (Fig 6E and 6F).
Fig 6. Mice lacking cathelicidin are proof in opposition to induction of EAE no matter common infiltration of spinal twine T cells.
EAE was induced in WT C57BL/6J and cathelicidin KO (Camp−/−, KO) mice on day 0. (A, B) On days 7 and 14, CD45extreme cell infiltration into the spinal twine was quantified by flow into cytometry. (C, D) Immune cell subsets inside the CD45extreme gate had been delineated on day 14 inside the spinal twine then (E, F) CD3+ T cell numbers inside the spinal twine had been confirmed on day 14 by immunofluorescence. (G) Neutrophil launch of cathelicidin was seen in shut contact with T cells inside the spinal twine. (H, I) On day 7 draining inguinal lymph nodes had been eradicated and CD4+ T cells isolated. Gene expression variations between WT and KO T cells had been assessed on a Nanostring mouse immunology chip (J, Okay) Splenic CD4+ T cells from naïve WT mice had been incubated with CD3/CD28 stimulation and a few.5 μM synthetic cathelicidin for 24 hours sooner than activation was assessed by flow into cytometry. Data confirmed are explicit individual information elements with (B, D, F) line at median. Statistical assessments used: (I) two-tailed t assessments with plenty of comparability correction; (J, Okay) paired two-tailed t check out. N values: A and B– 8–10; C–marketing consultant plot of three–9 mice; D– 3–8; F– 18–29 sections from 3–4 mice; I– 3, J– 6, Okay– 6. Data obtainable at 10.6084/m9.figshare.20310363. Cath, cathelicidin; EAE, experimental autoimmune encephalomyelitis; KO, knockout; WT, wild-type.
Together, these information current that cathelicidin is broadly expressed all through EAE and performs an important, nonredundant perform in sickness pathogenesis. However, this was not secondary to a decrease inside the total number of T cells or completely different immune cells stepping into the CNS.
As the final magnitude of immune cell flux into the CNS was associated in WT and KO mice, and spinal twine T cell numbers on the height of sickness had been the an identical, we because of this reality hypothesised that the phenotype of the T cells, and the cytokines they produced, had been altered inside the absence of cathelicidin. Production of proinflammatory cytokines from T cells is of essential significance to the occasion of maximum EAE sickness [18,54–56]. We have beforehand confirmed that cathelicidin strongly preferentially potentiates Th17 nevertheless not Th1 or Th2 differentiation all through acute responses [31] and so we hypothesised the an identical phenomenon was occurring all through EAE, notably as we seen that T cells inside the lymph nodes and spinal twine (Fig 6G) had been uncovered to cathelicidin all through sickness.
To research this, we decided to characterise T cells inside the draining lymph node, merely sooner than they switch into the spinal twine and provoke observable sickness. We isolated CD4+ T cells from the inguinal node of WT and KO mice on day 7 post-immunisation and analysed gene expression variations between the strains of mice, using a Nanostring Immunology chip. A number of genes had been altered between WT and KO T cells (Fig 6H).
Firstly, T cells isolated from the inguinal lymph nodes of KO mice (because of this reality differentiating inside the absence of cathelicidin after induction of EAE) had been a lot much less activated than these from WT mice. In naïve mice, activation standing of or cytokine manufacturing by T cells in KO mice simply is not completely completely different to WT mice (S4 Fig; [31]). However, in EAE expression of genes encoding CD27, PD1, LFA-1, ICOS, and LCP2 had been significantly lower in KO CD4+ T cells (Fig 6I). To affirm these findings on the protein stage and to take a look at if this was a direct impression of cell publicity to cathelicidin, we incubated isolated splenic CD4+ T cells with synthetic cathelicidin ex vivo, alongside CD3/CD28 stimulation. In this experiment we seen, agreeing with the Nanostring information, an enormous up-regulation of PD1 (Fig 6J) and CD44 expression, and an absence of CD62L (Fig 6K) following publicity to cathelicidin. These information counsel that cathelicidin is able to improve T cell activation.
Cathelicidin drives Th17 cell differentiation and plasticity
Next, we well-known that many genes encoding proteins which could be part of the Th17 differentiation pathway had been down-regulated in KO mice. These included the TGF-β receptors, STAT3, RORγt, and the aryl hydrocarbon receptors AHR and SOCS3 (Fig 7A). The large number of genes modulated by the absence of cathelicidin counsel this is usually a key pathway by the use of which cathelicidin mediates its purposeful affect, supporting our earlier work on this space. Importantly, displaying specificity inside the immunomodulation, genes concerning the Th1 and Th2 pathways weren’t altered in KO mice (Fig 7B), demonstrating in vivo that cathelicidin would not suppress all cytokine manufacturing indiscriminately nevertheless significantly impacts Th17-related genes.
Fig 7. In the absence of cathelicidin T cell differentiation into Th17 cells and to exTh17 cells is impaired.
EAE was induced in WT C57BL/6J and cathelicidin KO (Camp−/−, KO) mice on day 0. On day 7, draining inguinal lymph nodes had been eradicated and CD4+ T cells isolated. (A-B) Gene expression variations between WT and KO T cells had been assessed on a Nanostring mouse immunology chip, and (C) on days 0, 4, and 7, IL-17 manufacturing was assessed by flow into cytometry inside the inguinal lymph nodes. (D, E) On day 14, cytokine manufacturing was assessed by flow into cytometry or (F) by ELISA inside the spinal twine. (G) WT splenic CD4+ T cells had been cultured with Th17 driving medium for 48 hours (incubation 1, inc 1) then recombinant IL-12 for 72 hours (incubation 2, inc 2) sooner than cytokine manufacturing was assessed by flow into cytometry. (H) On day 7 of EAE inguinal lymph nodes had been far from WT mice and incubated for 72 hours with IL-12 and synthetic cathelicidin. (I) Human peripheral blood T cells had been incubated with TGF-β and anti-CD3/CD28 stimulation for then IL-12 for 3 days, inside the presence or absence of recombinant human cathelicidin (LL-37), after which IFN-γ was measured by flow into cytometry. Data confirmed are explicit individual information elements with traces at median. N values: A, B– 3; C– 3–11; D– 7–8; E– 9–10; F– 5; G– 6 for UT and Cath ++, 4 for Cath −+ and +−; H– 6, I–3. Statistical assessments used: (A, B)–two-tailed t assessments with put up hoc correction for plenty of comparisons; (C)–two-tailed t check out; (D, E)–two-tailed t check out; (G, H, I)–paired two-tailed t check out. Data obtainable at 10.6084/m9.figshare.20310363. Cath, cathelicidin; EAE, experimental autoimmune encephalomyelitis; inc, incubation; KO, knockout; WT, wild-type.
To research this on the protein stage, we isolated CD4+ T cells from the inguinal node. The manufacturing of IL-17A was definitely significantly suppressed in mice lacking cathelicidin as compared with WT animals at day 7 inside the sickness course (Fig 7C), nevertheless not at baseline, indicating that KO mice do not reveal this defect earlier to an immunological drawback. CD4+ T cells established a basal stage of IL-17A manufacturing in response to EAE induction, regardless of genotype (Fig 7C); however, when the Th17-biased immune response amplified at day 7 in WT mice, the an identical amplification did not occur in KO mice. This was associated to security from excessive pathology, in concordance with plenty of earlier analysis demonstrating {{that a}} low cost in IL-17 manufacturing leads to a lot much less excessive EAE sickness [12,13,57].
IL-17-producing Th17 cells are, however, not your complete story in EAE pathogenesis. There is considerable plasticity of Th17 subsets counting on the cytokines to which they’re uncovered [11,58–63]. In specific, Th17 cells (RORγt+, producing IL-17), which can be uncovered to IL-12 or to IL-23, up-regulate IFN-γ manufacturing in a STAT4- and Tbet-dependent model [58,59]. Therefore, all through EAE, early RORγt+ IL-17A+ cell populations inside the draining lymph node lose IL-17A and alter right into a pathogenic IFN-γ+ “ex-Th17” inhabitants [11,61–65]—definitely, almost the entire T cell IFN-γ manufacturing inside the spinal twine is from cells that had been as quickly as IL-17 producers [11]. Early suboptimal Th17 potentiation inside the lymph node, inside the absence of cathelicidin, could modulate this course of, with a consequent lessening of the frequency of these cells inside the CNS. We hypothesised that cathelicidin potentiates EAE pathology not solely by enhancing early Th17 differentiation however moreover by influencing later Th17 to exTh17 conversion.
To check out this, we checked out cytokine manufacturing inside the spinal twine on day 14 of EAE. Th17 cell numbers inside the spinal twine had been lowered at peak sickness, nevertheless not significantly (Fig 7D). Instead, in settlement with our hypothesis, we well-known an enormous low cost in IFN-γ manufacturing by CNS CD4+ T cells (Fig 7E).
The conversion of Th17 cells to IFN-γ producers occurs following IL-12 or IL-23 alerts [58,59,64,66]. It was potential that cathelicidin KO mice had a lot much less of these cytokines inside the CNS, nevertheless we confirmed that this was not the case with spinal twine wash ELISAs (Fig 7F). Therefore, we proposed that cathelicidin is able to potentiate the response to the obtainable CNS cytokines in Th17 cells within the an identical method it potentiates responses to TGF-β in naive T cells.
To study this, we cultured WT splenic T cells in Th17 differentiation medium for 48 hours inside the presence or absence of two.5 μM cathelicidin. Cells had been then washed and reincubated with IL-12 to promote IFN-γ manufacturing, as soon as extra inside the presence or absence of cathelicidin. We found (Fig 7G) that cathelicidin strongly promoted IFN-γ manufacturing in cells that had beforehand been in Th17-driving circumstances.
We questioned at which stage cathelicidin alerts are important for this conversion to IFN-γ producers. To reply this, 2 phases of cathelicidin publicity had been supplied—each inside the preliminary Th17-driving circumstances or inside the later IL-12 medium (Fig 7G). We found that if cathelicidin was included in one amongst these phases, no boosting of IFN-γ manufacturing was seen—however when it was included in every phases, necessary enhancement of IFN-γ occurred. This implies that the total differ of cathelicidin-producing cells described in Figs 1 and 2 may contribute to this phenotype, with neutrophils initially promoting Th17 differentiation inside the lymph nodes and priming for transition to ex-Th17 cells, however moreover spinal twine neutrophils and microglia/macrophages doubtlessly driving this pathogenic T cell plasticity on the net website of hurt.
Next, we investigated whether or not or not T cells inside the draining lymph nodes of mice all through early EAE would enhance their IFN-γ manufacturing within the occasion that they’d been uncovered to cathelicidin ex vivo. We immunised WT mice and eradicated the draining inguinal lymph nodes on day 7 post-immunisation. We restimulated lymph node single cell suspensions with MOG peptide inside the presence of IL-12 to induce conversion of antigen-specific T cells (Fig 7H). Exogenous cathelicidin added in to this course of enhanced IFN-γ manufacturing, indicating that publicity to cathelicidin inside the spinal twine could possibly be anticipated to extra enhance this conversion to ex-Th17 cells.
Finally, we determined whether or not or not human T cells reply within the an identical method as murine T cells to cathelicidin. We cultured peripheral blood T cells from healthful grownup human donors with TGF-β after which with IL-12, inside the presence or absence of two.5 μM human cathelicidin (LL-37). Cells that had been uncovered to cathelicidin produced significantly additional IFN-γ in these circumstances than those that did not (Fig 7I). This because of this reality agrees with the murine information.
Together, these information level out that the expertise of a pathogenic ex-Th17 inhabitants of T cells inside the CNS is impaired inside the absence of cathelicidin signalling. These outcomes lead us to recommend a model by means of which cathelicidin has 3 impacts on the expertise of pathogenic T cells in EAE. Firstly, it instantly will improve the activation of T cells. Next, it significantly potentiates Th17 differentiation and IL-17 manufacturing inside the lymph node. Finally, it enhances Th17 to exTh17 differentiation and IFN-γ manufacturing inside the spinal twine.
Discussion
Here, we reveal that the antimicrobial peptide cathelicidin drives excessive autoimmune sickness inside the mouse model of MS. Specifically, publicity of CD4+ T cells inside the draining lymph node to neutrophil-derived cathelicidin enhances their differentiation into Th17 cells. When these cells switch into the CNS, they’re extra uncovered to cathelicidin launched by neutrophils, microglia, and endothelial cells, and this potentiates Th17 differentiation into IFN-γ producing “exTh17” cells. This work extends earlier analysis displaying that neutrophils are important in autoimmune sickness by providing a mechanism by the use of which they’re going to drive irritation—the actual potentiation of IFN-γ-producing exTh17 cells inside the CNS.
Cathelicidin is broadly expressed in autoimmune and autoinflammatory circumstances [67] along with all through infections and performs a key perform in driving irritation in these illnesses—along with persistent obstructive pulmonary sickness [68], psoriasis [69,70], and atherosclerosis [71]. Plenty of proinflammatory mechanisms of movement of cathelicidin have been described along with activation of the NLRP3 inflammasome [72], promoting uptake of self-nucleic acids [36,67,69], and enhancement of cytokine and chemokine launch [43,73–75]. To these, we now add explicit promotion of pathogenic T cell differentiation and long-term have an effect on on adaptive T cell cytokine manufacturing. We have beforehand confirmed that cathelicidin induces Th17 cell differentiation by the use of potentiation of TGF-β and aryl hydrocarbon receptor signalling—these are pathogenic cells that induce sickness in quite a lot of autoimmune circumstances [2,9,76,77]. Previously, cathelicidin has been confirmed to be recognised as a T cell autoantigen in psoriasis [78] and to chemoattract T cells in custom [49], suggesting plenty of mechanisms by the use of which the peptide could alter autoimmune T cell enchancment and efficiency. Indirect mechanisms are moreover potential, notably by the use of an affect on dendritic cell carry out. We have confirmed that cathelicidin alters dendritic cell differentiation and priming of T cells [79,80], and others have confirmed it may truly kind immune complexes with DNA to promote plasmacytoid DC activation [69].
This implies that the affect of this innate peptide is extra prone to be wide-ranging in quite a lot of autoimmune illnesses pushed by T cell dysfunction. As successfully as psoriasis and MS, that is because of this reality extra prone to be important in illnesses similar to neuromyelitis optica and Crohn’s sickness, every of which attribute pathogenic Th17 cell populations and big influxes of neutrophils into contaminated tissues [81–86].
We reveal proper right here that cathelicidin is expressed inside the healthful human thoughts, by means of which it was produced by neutrophils, microglia/macrophages, and endothelial cells. The perform of this cathelicidin launch is in the intervening time unknown. We moreover demonstrated that cathelicidin was broadly launched inside the contaminated mouse spinal twine all through EAE and energetic MS lesions in human thoughts. It has not beforehand been described in MS or EAE, although expression has been well-known inside the olfactory bulb, cerebellum, medulla oblongata, and spinal twine all through experimental meningitis expression [87]. The expression of cathelicidin in our analysis agrees with earlier work displaying its launch in several applications could also be triggered by mediators launched all through sterile irritation—similar to leukotriene B4 [88] or phenylbutyrate [89]—along with strictly infection-triggered mediators. A bigger information of the perform of antimicrobial peptides in sterile irritation and inside the CNS significantly is required as we now begin to know the wide-ranging outcomes these peptides have on the immune system.
We seen co-localisation of cathelicidin with microglia and endothelial cells along with neutrophils. It is hard to rule out co-localisation owing to shut by neutrophil degranulation releasing cathelicidin and it being taken up by completely different cells. We think about that microglia are actively producing cathelicidin as our mining of revealed datasets revealed microglia can particular the cathelicidin gene. Also, there’s supporting proof from earlier analysis; endothelial manufacturing of cathelicidin has been well-known in meningitis infections of mice [90], and microglial manufacturing has been demonstrated in vitro [91–93]. The question of which cells are important for releasing cathelicidin into the neighborhood of CNS T cells stays open. We have moreover tried to answer this question with our conditional KO lysMcre mice. EAE in these mice—which do not have cathelicidin of their microglia or neutrophils nevertheless do of their endothelial cells (and in several cells similar to mast cells and epithelium)—has an almost an an identical sickness course to full KO mice. This implies that the neutrophil cathelicidin inside the lymph node and microglial cathelicidin inside the spinal twine are key nevertheless that endothelial cathelicidin is unimportant. Relative contributions from microglia and neutrophils inside the spinal twine are the principle goal of current evaluation. In specific, will probably be instructive to generate microglia-specific, macrophage-specific, and neutrophil-specific cathelicidin KO mice. This would allow us to unravel the affect of cathelicidin produced by each cell sort and the best way each cell’s manufacturing differentially impacts the incoming T cells.
The differentiation of Th17 cells inside the draining inguinal lymph node and its enhancement by cathelicidin agrees with our earlier information [31] the place we demonstrated this phenomenon occurring inside the 72 hours following inoculation with heat-killed pathogens and with influenza virus. Now, we lengthen these analysis by demonstrating this neutrophil-driven Th17 potentiation occurs in longer-term inflammatory fashions.
The exTh17 conversion experiments carried out ex vivo reveal that every early (lymph node) and late (CNS) cathelicidin are important for the last word differentiation of IFN-γ-producing cells. Our discovering proper right here, that cathelicidin induces IFN-γ manufacturing in cells beforehand incubated in Th17-driving circumstances, is stunning. In our earlier analysis, we found that cathelicidin incubated with naïve T cells would not affect IFN-γ manufacturing (positively or negatively) in Th1-driving circumstances, and it suppresses IFN-γ in cells which could be actively receiving TGF-β alerts (every of which had been revealed in [31]). These disparate outcomes on cytokine manufacturing in naïve and activated T cells, in a number of cytokine milieu, reveal the complexity of these applications. Unravelling the signalling pathways involved will in all probability be essential. Interestingly, the extra differentiation of spinal twine Th17 cells into exTh17 cells [11,59] has been confirmed to be relying on the aryl hydrocarbon receptor [11]. Our earlier analysis demonstrated that preliminary enhancement of Th17 cells by cathelicidin is likewise AhR-dependent, and we hypothesise {{that a}} potentiation of AhR signalling inside the spinal twine is occurring in T cells, which come into contact with launched cathelicidin there.
Recent analysis have demonstrated the gut microbiome influences finish end in EAE (reviewed in [94]). We know that cathelicidin KO mice have an altered microbiome [95,96]; however, we do not think about that the gut microbiome has an important significance in our analysis owing to the reality that WT splenic T cells given cathelicidin in vitro behave the an identical as T cells in vivo in WT mice. In addition, naïve KO and WT mice have no variations in T cell activation or cytokine manufacturing. However, it could be associated that our mice had been housed in individually ventilated cages in SPF circumstances, and mice housed otherwise may current altered gut and, subsequently, systemic immune responses.
Overall, this analysis describes antimicrobial peptide expression inside the CNS and establishes the perform of cathelicidin in directing pathogenic T cell responses in long-term irritation. This work extends earlier analysis displaying that neutrophils are important in autoimmune sickness by providing a mechanism by the use of which they’re going to drive irritation—the actual potentiation of IFN-γ-producing cells inside the CNS.
Methods
Mice
WT C57Bl/6JOlaHsd and cathelicidin KO (Camptm1Rig, KO) and LysMCreFLCamp mice had been bred and housed in individually ventilated cages, beneath explicit pathogen-free circumstances. Female mice between 9 and 13 weeks of age had been used for EAE experiments; for in vitro cell stimulations, every feminine and male mice between 6 and 12 weeks had been used. We have beforehand determined no intercourse variations exist in Th17 potentiation by cathelicidin. KO mice had been backcrossed onto WT shares for 10 generations. Mice had been housed in accordance with the ASPA code of apply for the UK; this consists of temperatures from 19 to 24°C, humidity from 45% to 65%, and a 12-hour light/darkish cycle.
All animal experiments had been carried out by completely educated personnel in accordance with Home Office UK enterprise licences PAF438439 and 70/8884, beneath the Animal (Scientific Procedures) Act 1986. This enterprise licence outlined this technique of labor and was licensed by the University of Edinburgh Animal Welfare Ethical Review Body. Each experimental protocol was licensed by the University of Edinburgh veterinary group.
EAE
WT and KO 9- to 13-week-old female C57BL/6J mice had been injected on day 0 subcutaneously in every hind legs with 140 μg MOG35–55 emulsified in full Freund’s adjuvant (CFA), and on days 0 and 1 intraperitoneally with 100 μl of fifty ng/ml pertussis toxin in PBS (Hooke Laboratories, #EK-2110). Mice had been scored every 2 days until day 6, after which each day primarily based totally on an EAE scale: 0 –no sickness, 1 –flaccid tail, 2 –impaired gait and/or impaired righting reflex, 3 –significantly impaired gait, and 4 –partially hind leg paralysis. Mice with a grade 2 or above had been equipped with hydrated meals on the bottom of the cage. Mice with grade 4 had been culled immediately.
Murine tissue and single-cell preparations
Mice had been culled by perfusion with PBS and exsanguination by severing of predominant vessels. Single-cell preparations of spleens and lymph nodes had been achieved by mashing the tissues by the use of a 100-μM strainer and washing with PBS. For the spleen, crimson blood cells had been lysed using RBC Lysis Buffer, as per the producer’s instructions (BD Biosciences, #555899). Preparations of thoughts and spinal twine had been achieved by transferring full thoughts and spinal twine to a glass Dounce with 2 ml HBBS and manually homogenising for 50 passes of the Dounce. Cell suspension was centrifuged, and the cell pellet resuspended in 1 ml FBS and 33% Percoll, and 1 ml 10% FBS was layered on prime and spun for quarter-hour at 800×g at 4°C with no break. Cells had been washed and resuspended in PBS ready for staining.
Flow cytometry
Cells had been stained for flooring markers for half-hour at 4°C, protected in opposition to light. Intracellular cytokines had been assessed by incubating cells for 4 hours at 37°C with Cell Stimulation Cocktail containing protein transport inhibitors (eBioscience, #00-4970-03). Cells had been mounted, permeabilised, and stained for cytokines using BD Cytofix/Cytoperm (BD Biosciences, #554722) as per the producer’s ideas. Cells had been mounted, permeabilised, and stained for transcription parts using the True-Nuclear Transcription Factor Buffer Set (Biolegend, #424401). Cytokines and transcription parts within the an identical FACS panel had been stained with the FOXP3 transcription subject staining tools (eBioscience, #00-5523-00), as per the producer’s instructions. Cell viability was assessed by flow into cytometry fixable reside/ineffective yellow (ThermoFisher #L34959) or Zombie NIR Fixable Viability Kit (Biolegend, #423105).
Flow cytometry antibodies
Mouse.
CD45 (clone 30-F11, Biolegend, #103127, 1:200), CD45 (30-F11, BD Biosciences, #564225, 1:200) CD4 (GK1.5, Biolegend, #100406, 1:200), CD4 (GK1.5, Biolegend, #100453, 1:200), CD8 (53–6.7, Biolegend, #100741, 1:200), IL-17A (TC11-18H10.1, Biolegend, #506938, 1:100), IL-17F (9D3.1C8, Biolegend, #517004, 1:100), IFNγ (XMG1.2, Biolegend, #505826, 1:100), CD11c (NF18, Biolegend, #101226, 1:200), CD11b (M1/70, Biolegend, #101212, 1:150), Ly6G (IA8, Biolegend, #127618, 1:200), I-A/I-E (M5/114.15.2, Biolegend, #107635, 1:300), F4/80 (BM8, Biolegend, #123117, 1:200), Ly6C (HK1.4, BD Biosciences, #128021, 1:150), B220 (RA3-6B2, Biolegend, #103245, 1:150), RORγT (B2D, eBioscience, #17-6981-80, 1:100), PD1 (RMP1-30, Biolegend, #109115, 1:300), and CD62L (MEL-14, Biolegend, #104428, 1:300).
NanoString
WT and Camp−/− KO mice had been immunised as beforehand described. On day 7 post-immunisation, mice had been perfused with 10 ml PBS and inguinal lymph nodes had been processed as above. DAPI−CD3+CD4+ T cells had been sorted using a BD FACSAria II (BD Biosciences), and RNA was extracted immediately using the Qiagen RNAeasy Mini Kit (Qiagen, #74104), as per the producer’s ideas. Multiplex gene expression analysis (Mouse Immunology Panel) was carried out by HTPU Microarray Services, University of Edinburgh. Data analysis was carried out using nSolver 4.0 and nCounter Advanced Analysis software program program.
Peptides
Synthetic murine cathelicidin (mCRAMP) (GLLRKGGEKIGEKLKKIGQKIKNFFQKLVPQPEQ) and human cathelicidin (LL-37) (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) had been synthesised by Almac (Penicuik, Scotland) using Fmoc sturdy phase synthesis and reverse phase HPLC purification. Peptide id was confirmed by electrospray mass spectrometry. Purity (>95% space) was determined by RP-HPLC and web peptide content material materials determined by amino acid analysis. Lyophilized peptides had been reconstituted in endotoxin free water at 5 mg/ml. Reconstituted peptides had been examined for endotoxin contamination using a Limulus Amebocyte Lysate Chromogenic Endotoxin Quantitation Kit (Thermo Scientific, UK #88282).
In vitro plasticity experiments
Mouse.
Whole splenocytes had been prepared by mashing the tissue by the use of a 100-μM strainer and washing with PBS. Red blood cells had been lysed using RBC lysis buffer, as per the producer’s instructions (BD Biosciences, #555899). A total of 150,000 cells had been plated per successfully of round-bottom 96-well plates in full medium (RPMI, 10% foetal calf serum, 10 fashions/ml penicillin, 10 μg/ml streptomycin, and a few mM L-glutamine, all outfitted by Gibco, Thermo Fisher UK). All cells had been differentiated for 48 hours inside the presence of plate-bound αCD3 (2.5 μg/ml; Biolegend, #100339), rIL-6 (20 ng/ml; Biolegend, #575706), rIL-23 (20 ng/ml; Biolegend, #589006), and rTGFβ (3 ng/ml; Biolegend, #580706), with or with out 2.5 μM mCRAMP. Media was rigorously eradicated and altered with each rIL-12 (25 ng/ml; Biolegend #575402), with or with out 2.5 μM synthetic cathelicidin. Cultures had been incubated for a further 72 hours.
In some cultures to judge cathelicidin affect on T cell activation, splenocytes had been processed as above and cultured with plate-bound αCD3 (2.5 μg/ml; Biolegend, #100339) inside the presence or absence of two.5 μM mCRAMP for 48 hours.
Human.
Around 3 ml peripheral venous blood was taken from healthful grownup donors in accordance with University of Edinburgh ethical agreements (AMREC 20-HV-069). T cells had been isolated immediately using the EasySep direct human T cell isolation tools (StemCell Technologies #19661) in response to producer’s instructions. Approximately 2 × 105 cells per successfully had been plated in a 96-well round-bottom plate in full medium (RPMI, 10% foetal calf serum, 10 fashions/ml penicillin, 10 μg/ml streptomycin, and a few mM L-glutamine, all outfitted by Gibco, Thermo Fisher UK). EasySep Immunocult stimulation cocktail (StemCell Technologies #10971) and three ng/ml rTGFβ1 (Biolegend #781802) had been added to all wells, with or with out 2.5 μM synthetic human cathelicidin (LL-37). Five days later, cells had been washed twice and replated with 50 ng/ml rIL-12 (Biolegend #573002) as soon as extra with or with out LL-37. Three days later, IFN-γ manufacturing was assessed by flow into cytometry.
In vitro restimulation experiments
On day 7 post-immunisation, inguinal lymph nodes had been isolated and prepared by mashing the tissue by the use of a 100-μM strainer and washing with PBS. A total of 100,000 cells had been plated per successfully in round-bottom 96-well plates in full medium (RPMI, 10% foetal calf serum, 10 fashions/ml penicillin, 10 μg/ml streptomycin, and a few mM L-glutamine, all outfitted by Gibco, Thermo Fisher UK). All cells had been incubated for 72 hours with MOG (2.5 μg/ml; Sigma-Aldrich, M4939), with or with out rIL-12 (25 ng/ml; Biolegend #575402) and cathelicidin (2.5 μM).
ELISA
Concentrations of mouse IL-23 (R&D Systems, #DY1887) and IL-12 (R&D Systems #M1270) had been determined in spinal twine supernatants 7 and 14 days post-immunisation by ELISA, as per the producer’s ideas.
Immunohistochemistry on mouse tissue
Mice had been perfused with 4% paraformaldehyde (PFA) (Sigma-Aldrich, #158127) at indicated time elements after immunisation. Whole thoughts, spinal twine, and inguinal lymph nodes had been isolated and caught in 4% PFA in a single day at 4°C. Brains and spinal cords had been transferred to fifteen% sucrose for 24 hours, then 30% sucrose for 24 hours and embedded in optimum chopping temperature (OCT) compound to be cryosectioned (5 μm). Lymph nodes had been transferred to 70% ethanol and embedded in paraffin.
Frozen sections had been air dried for 10 minutes and paraffin-embedded slides had been dewaxed and rehydrated. Haematoxylin–eosin (HE) staining was carried out on tissue sections to know inflammatory infiltration and the state of affairs of lesions all through the spinal twine. For spinal twine sections, antigens had been retrieved each by microwaving in tri-sodium citrate buffer (1 L distilled H2O, 2.94g sodium citrate, 0.5 ml Tween20 (pH6)), pH6 for 5 minutes or by 10 minutes incubation with 5 mg/ml proteinase Okay (Thermo Fisher UK, #AM2548) at 37 ranges. Slides had been permeabilised with Triton X-100 (Sigma, #9036-19-5, 1:1,000) and blocked with 25% donkey serum for 1 hour at room temperature (RT), then main antibodies had been incubated in 10% donkey serum in a single day at 4°C. Slides had been then incubated with a combination of the subsequent secondary antibodies: donkey anti-rat 488 (Invitrogen, #A21208), donkey anti-rabbit 555 (Invitrogen, #A31572), hen anti-rat 647 (Invitrogen, #A31572), or hen anti-goat 647 (Invitrogen, #214690) all at 1:500 for 1 hour at RT. Slides had been counterstained with Hoechst at 1:1,000 in dH2O (Abcam, #H1399). For lymph node sections, antigens had been retrieved using 5 mg/ml proteinase Okay, as above. Slides had been blocked with 3% H2O2, 25% goat serum, and avidin/biotin, and the first main antibody was added in a single day at 4°C. The antigen was visualised using DAB Substrate tools (Vector Labs, #SK-4105) and subsequently blocked with Bloxall Endogenous Blocking Solution (Vector Labs, #SP-6000-100) and 25% horse serum. The second main antibody was added in a single day at 4°C and visualised the subsequent day using Vector Red Substrate Kit (Vector Labs, SK-5100). Slides had been counterstained with haematoxylin. Stained sections had been mounted in Fluoromount G, scanned on a ZEISS AxioScan.Z1 slide scanner and analysed using ZEISS ZEN software program program. For NeuN cathelicidin staining, sections had been imaged on a Leica SPE confocal microscope.
Antibodies (mouse)
CRAMP (rabbit polyclonal, Innovagen, #PA-CRPL, 1:500–1:1,000), Ly6G (IA8, Biolegend, #127601, 1:50), CD3 (17A2, Biolegend, #100209, 1:50), CD31 (rat polyclonal, R&D Systems, #AF3628, 1:100), peripheral node addressin (MECA-79, Novus Biologicals, #NB100-77673SS, 1:100), Iba1 (goat polyclonal, Abcam #ab5076, 1:500), F4/80 (BM8, eBioscience, #14–4801 1:100), and NeuN (mouse monoclonal 1B7, Abcam, #ab104224, 1:500).
Human postmortem thoughts tissue
Postmortem tissue from secondary progressive MS victims and administration victims who died of nonneurological causes, with ethical approval and educated consent, had been obtained from the UK Multiple Sclerosis Tissue Bank in collaboration with Professor Anna Williams, University of Edinburgh. Tissue was snap frozen and lesions categorised as energetic, persistent energetic, persistent inactive, and remyelinating using Luxol Fast Blue-Cresyl Violet staining and Oil Red O staining, in response to the International Classification of Neurological Diseases.
Immunohistochemistry on human tissue
Frozen tissue sections had been mounted in 4% PFA and subsequently delipidised in methanol. Antigen retrieval was carried out with heating in acid citric buffer and sections blocked with 10% serum. Sections had been incubated in a single day at 4°C with main antibodies for CD31 or CD68 (antibodies listed underneath). On day 2, sections had been incubated with the secondary ImmPRESS-AP Horse Anti-Mouse IgG Polymer Detection Kit, Alkaline Phosphatase (Vector, #MP-5402) for half-hour at RT and visualised with the Vector Blue Alkaline Phosphatase Substrate Kit (Vector Laboratories #SK-5300). Following this, sections had been incubated in a single day at 4°C with the second main antibody for cathelicidin. On day 3, secondary antibody ImmPRESS-AP Horse Anti-Rabbit IgG Polymer Detection Kit Alkaline Phosphatase (Vector, #MP-5401) was added and visualised with the Vector Red Alkaline Phosphatase Substrate Kit (Vector Laboratories #SK-5100). For neutrophil elastase (NE) and cathelicidin staining, frozen tissue sections had been mounted in acetone for 5 minutes and delipidised in ethanol for 10 minutes. Antigens had been retrieved by heat-induced sodium citrate and permeabilised with Triton X100. True black in 70% ethanol (Cambridge Bioscience #BT2300, dilution 1:20) was added to the slides for 20 seconds and washed completely with PBS and subsequently blocked with 25% donkey serum. Primary antibodies had been incubated in a single day at 4°C. In all samples, nuclei had been counterstained with Hoechst as above and slides mounted with Fluoromount G medium. Relevant IgG isotype antibodies and secondary antibodies alone had been used as detrimental controls.
Cathelicidin-positive cells and NE cathelicidin double-positive cells had been manually quantified in MS brains inside each lesion sort all through your complete lesion and calculated as optimistic cells per cm2. The suggest space of all lesions was calculated, and three white matter areas of this measurement had been counted in administration brains.
Antibodies (human)
Cathelicidin (rabbit polyclonal, abcam #ab69192, dilution 1:100), cathelicidin (rabbit polyclonal, abcam #ab69484, dilution 1:100), NE (clone NP57, Dako M0752, dilution 1:100), CD68 (KP1, Dako M0814, dilution 1:100), and CD31 (JC70A, Dako M0823, dilution 1:100).
HDP expression in revealed RNA sequencing databases
In mice and folks, revealed sequencing databases had been acknowledged using searches in Google Scholar, PubMed, and GEO Accession Viewer. The search phrases for the datasets had been as follows: “cell type” AND “rna seq” AND “human/mouse” NOT “iPSC.” The search was filtered to include sequence entry sort solely. For information deposited on a laboratory website online, the HDP gene determine was entered into the search engine and gene expression assessed. cd3g/CD3G was used as a detrimental administration reference gene that encodes for CD3, which is a protein difficult expressed solely on T cells, because of this reality simply is not expressed by CNS-resident cells.
Statistics
Two groups had been in distinction with two-way unpaired or paired t check out. Multiple groups had been in distinction by one- or two-way ANOVA analysis. All information had been analysed with Graphpad Prism. Sample sizes and what each information stage on the graphs characterize are detailed inside the decide legends.
Supporting data
S1 Fig. Establishment of the EAE model in WT mice.
WT mice had been immunised with MOG in CFA and pertussis toxin was given. Mice had been (A) tracked for medical indicators of sickness over a time course and (B) at quite a few events had been perfused with 4% PFA and spinal cords eradicated. HE staining was carried out to detect inflammatory infiltrate and (C, D) anti-CD3 immunofluorescent staining carried out to detect T cell infiltrate. (E) Representative plot of IL-17A+ CD4+ T cells inside the spinal twine on day 14. The graph reveals Th17 cell numbers (IL-17A+ and IL-17F+) inside the spinal twine had been quantified by flow into cytometry. Data confirmed are (A) suggest with regular error and (D, E) explicit individual information elements with line at median. N values: A– 85 mice; D– 14–50 sections from 3–4 mice; E– 4. Images are marketing consultant of three mice. Statistical check out utilized in D–one-way ANOVA. Data obtainable at 10.6084/m9.figshare.20310363. CFA, full Freund’s adjuvant; EAE, experimental autoimmune encephalomyelitis; HE, haematoxylin–eosin; MOG, myelin oligodendrocyte glycoprotein; PFA, paraformaldehyde; WT, wild-type.
https://doi.org/10.1371/journal.pbio.3001554.s001
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S2 Fig. Generation and validation of the LysMCre mouse.
The WT Camp gene (A) consists of 4 exons on chromosome 9. Camptm1a(EUCOMM)Hmgo ES cells (JM8A3.N1; cell clone ID HEPD0722_1_E10; MGI:4950203) cells concentrating on the Camp locus had been purchased from EUCOMM, injected into C57/Bl6J blastocyst stage embryos and subsequently transferred to recipient female mice. Male chimeric progeny had been mated with C57Bl/6JCrl female mice to find out germ line transmission, confirmed by transient differ and prolonged differ PCR (Primer combos and sequences in Methods). Targeted mice (Camptm1a(EUCOMM)Hmgo; B) had been then crossed with ActFlpE (SJL-Tg(ACTFLPe)9205Dym/J) mice on C57Bl6/JCrl background mice to generate mice with a “flipped” allele (Camptm1a(EUCOMM)Hmgo / ACTFLPe; C) lacking the lacZ and neo vector cassettes, intercrossed to homozygosity and confirmed by PCR. Confirmation of Cre recombination to generate a conditional null allele (with excision of Camp exons 2–4) was supplied by administration of soluble tat Cre recombinase to at the least one cell Camptm1a(EUCOMM)Hmgo / ACTFLPe embryos obtained by IVF, transferred into recipients at 2.5 days, adopted by PCR affirmation and sequencing of the following conditional null allele on E12 embryos. Camptm1a(EUCOMM)Hmgo / ACTFLPe had been crossed with a myeloid-specific CRE-recombinase line LysMCre(Tg (Lyz2tm1(cre)Ifo) to generate the Camp conditional null mice (Camptm1a(EUCOMM)Hmgo / ACTFLPe / Tg (Lyz2tm1(cre)Ifo; D) designated LysMCreFLCamp mice and bred to congenicity for n = 10 generations. Breeding pairs homozygous for floxed Camp had been heterozygous or WT for LysMCre (designated LysMCreFLCamp and FLCamp, respectively) and studied experimentally as compared with littermates controls. (E) Primers and (F) sequences used.
https://doi.org/10.1371/journal.pbio.3001554.s002
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S4 Fig. Analysis of T cell populations in untreated WT C57BL/6J and Camp KO mice.
Mice had been culled between 6 and 12 weeks of age and inguinal lymph nodes (B, C, and E) and spleens (B, C, and F) had been harvested and analysed by flow into cytometry immediately. CD4+ and CD8+ T cell frequency and expression of activation markers PD-1 and CD62L in these organs had been assessed in every genotypes. Representative plots of CD4+ and CD8+ T cell frequency are confirmed and the graph reveals T cell frequency quantified by flow into cytometry (A-C). Representative plots of PD1 expression on CD4+ T cells are confirmed (A) and the graph reveals activation marker expression on CD4+ T cells inside the inguinal lymph node (E) and spleen (F). N values: 3–8 mice per genotype. KO, knockout; WT, wild-type.
https://doi.org/10.1371/journal.pbio.3001554.s004
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S2 Table. Murine microglia and oligodendrocyte databases accessed for analysis of HDP expression in CNS-resident cells.
The cell sort, information availability data, reference, CNS space and experimental state of affairs is listed. CNS, central nervous system; HDP, host-defence peptide.
https://doi.org/10.1371/journal.pbio.3001554.s006
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S4 Table. Human neuron, astrocyte, microglia, and oligodendrocyte databases accessed for analysis of HDP expression in CNS-resident cells.
The cell sort, information availability data, reference, CNS space, and experimental state of affairs is listed. CNS, central nervous system; HDP, host-defence peptide.
https://doi.org/10.1371/journal.pbio.3001554.s008
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Acknowledgments
We thank the Queen’s Medical Research Institute flow into cytometry group (Shonna Johnston, Will Ramsay, and Mari George), SURF histology group, and the Institute of Genetics and Cancer Nanostring Team (Alison Munro) for help and suggestion. We thank Dr Anne Astier, Dr Robert Gray, and Professor Julia Dorin for helpful discussions and Professor Steve Anderton for suggestion on the EAE model. We want to thank Matt Sharp, Julie Thomson, Ailsa Travers, and the University of Edinburgh Veterinary corporations group for help with mouse expertise, breeding, and maintenance.
References
- 1.
Dendrou CA, Fugger L, Friese MA. Immunopathology of plenty of sclerosis. Nat Rev Immunol. 2015;15(9):545–58. pmid:26250739 - 2.
Ivanov II, McKenzie BS, Zhou L, Tadokoro CE, Lepelley A, Lafaille JJ, et al. The Orphan Nuclear Receptor RORγt Directs the Differentiation Program of Proinflammatory IL-17+ T Helper Cells. Cell. 2006;126(6):1121–33. - 3.
Kurschus FC. T cell mediated pathogenesis in EAE: Molecular mechanisms. Biom J. 2015;38(3):183–193. pmid:25900928 - 4.
Carlson T, Kroenke M, Rao P, Lane TE, Segal B. The Th17-ELR+ CXC chemokine pathway is essential for the occasion of central nervous system autoimmune sickness. J Exp Med. 2008;205(4):811–23. pmid:18347102 - 5.
Tzartos JS, Friese MA, Craner MJ, Palace J, Newcombe J, Esiri MM, et al. Interleukin-17 manufacturing in central nervous system-infiltrating T cells and glial cells is said to energetic sickness in plenty of sclerosis. Am J Pathol. 2008;172(1):146–55. pmid:18156204 - 6.
Stromnes IM, Goverman JM. Passive induction of experimental allergic encephalomyelitis. Nat Protoc. 2006;1(4):1952–60. pmid:17487182 - 7.
Ben-Nun A, Wekerle H, Cohen IR. The speedy isolation of clonable antigenspecific T lymphocyte traces in a position to mediating autoimmune encephalomyelitis. Eur J Immunol. 1981;11:195. pmid:6165588 - 8.
McPherson RC, Cambrook HE, O’Connor RA, Anderton SM. Induction of passive EAE using myelin-reactive CD4+ T cells. Methods Mol Biol. 2014;1193:187–98. pmid:25151007 - 9.
Yasuda Okay, Takeuchi Y, Hirota Okay. The pathogenicity of Th17 cells in autoimmune illnesses. Semin Immunopathol. 2019;41(3):283–297. pmid:30891627 - 10.
Ifergan I, Kebir H, Alvarez JI, Marceau G, Bernard M, Bourbonnière L, et al. Central nervous system recruitment of effector memory CD8+ T lymphocytes all through neuroinflammation depends on α4 integrin. Brain. 2011;134(12):3560–77. pmid:22058139 - 11.
Hirota Okay, Duarte JH, Veldhoen M, Hornsby E, Li Y, Cua DJ, et al. Fate mapping of IL-17-producing T cells in inflammatory responses. Nat Immunol. 2011;12(3):255–63. pmid:21278737 - 12.
Komiyama Y, Nakae S, Matsuki T, Nambu A, Ishigame H, Kakuta S, et al. IL-17 performs an important perform inside the enchancment of experimental autoimmune encephalomyelitis. J Immunol. 2006;177(1):566–573. pmid:16785554 - 13.
McGinley AM, Sutton CE, Edwards SC, Leane CM, DeCourcey J, Teijeiro A, et al. Interleukin-17A Serves a Priming Role in Autoimmunity by Recruiting IL-1β-Producing Myeloid Cells that Promote Pathogenic T Cells. Immunity. 2020;52(2):342–56.e6. pmid:32023490 - 14.
Olsson T. Cytokines in neuroinflammatory sickness: perform of myelin autoreactive T cell manufacturing of interferon-gamma. J Neuroimmunol. 1992;40(2–3):211–8. pmid:1430152 - 15.
Ley Okay. The second contact hypothesis: T cell activation, homing and polarization. F1000Res. 2014;3:37. pmid:25580220 - 16.
Furtado GC, Marcondes MCG, Latkowski J-A, Tsai J, Wensky A, Lafaille JJ. Swift entry of myelin-specific T lymphocytes into the central nervous system in spontaneous autoimmune encephalomyelitis. J Immunol. 2008;181(7):4648–55. pmid:18802067 - 17.
Stoll S, Delon J, Brotz TM, Germain RN. Dynamic imaging of T cell-dendritic cell interactions in lymph nodes. Science. 2002;296(5574):1873–6. pmid:12052961 - 18.
Langrish CL, Chen Y, Blumenschein WM, Mattson J, Basham B, Sedgwick JD, et al. IL-23 drives a pathogenic T cell inhabitants that induces autoimmune irritation. J Exp Med. 2005;201(2):233–40. pmid:15657292 - 19.
Simmons SB, Liggitt D, Goverman JM. Cytokine-regulated neutrophil recruitment is required for thoughts nevertheless not spinal twine irritation all through experimental autoimmune encephalomyelitis. J Immunol. 2014;193(2):555–63. pmid:24913979 - 20.
Pierson ER, Wagner CA, Goverman JM. The contribution of neutrophils to CNS autoimmunity. Clin Immunol. 2018;189:23–8. pmid:27377536 - 21.
Aubé B, Lévesque SA, Paré A, Chamma É, Kébir H, Gorina R, et al. Neutrophils mediate blood-spinal twine barrier disruption in demyelinating neuroinflammatory illnesses. J Immunol. 2014;193(5):2438–54. pmid:25049355 - 22.
Song J, Wu C, Korpos E, Zhang X, Agrawal SM, Wang Y, et al. Focal MMP-2 and MMP-9 train on the blood-brain barrier promotes chemokine-induced leukocyte migration. Cell Rep. 2015;10(7):1040–54. pmid:25704809 - 23.
Ouyang W, Kolls JK, Zheng Y. The natural capabilities of T helper 17 cell effector cytokines in irritation. Immunity. 2008;28(4):454–67. pmid:18400188 - 24.
Pelletier M, Maggi L, Micheletti A, Lazzeri E, Tamassia N, Costantini C, et al. Evidence for a cross-talk between human neutrophils and Th17 cells. Blood. 2010;115(2):335–43. pmid:19890092 - 25.
Grist JJ, Marro BS, Skinner DD, Syage AR, Worne C, Doty DJ, et al. Induced CNS expression of CXCL1 augments neurologic sickness in a murine model of plenty of sclerosis by the use of enhanced neutrophil recruitment. Eur J Immunol. 2018;48(7):1199–210. pmid:29697856 - 26.
Haschka D, Tymoszuk P, Bsteh G, Petzer V, Berek Okay, Theurl I, et al. Expansion of Neutrophils and Classical and Nonclassical Monocytes as a Hallmark in Relapsing-Remitting Multiple Sclerosis. Front Immunol. 2020;11:594. pmid:32411125 - 27.
Woodberry T, Bouffler SE, Wilson AS, Buckland RL, Brüstle A. The Emerging Role of Neutrophil Granulocytes in Multiple Sclerosis. J Clin Med. 2018;7(12). pmid:30513926 - 28.
Naegele M, Tillack Okay, Reinhardt S, Schippling S, Martin R, Sospedra M. Neutrophils in plenty of sclerosis are characterised by a primed phenotype. J Neuroimmunol. 2012;242(1–2):60–71. pmid:22169406 - 29.
Rumble JM, Huber AK, Krishnamoorthy G, Srinivasan A, Giles DA, Zhang X, et al. Neutrophil-related parts as biomarkers in EAE and MS. J Exp Med. 2015;212(1):23–35. pmid:25559893 - 30.
Steinbach Okay, Piedavent M, Bauer S, Neumann JT, Friese MA. Neutrophils amplify autoimmune central nervous system infiltrates by maturing native APCs. J Immunol. 2013;191(9):4531–9. pmid:24062488 - 31.
Minns D, Smith KJ, Alessandrini V, Hardisty G, Melrose L, Jackson-Jones L, et al. The neutrophil antimicrobial peptide cathelicidin promotes Th17 differentiation. Nat Commun. 2021;12(1):1285. pmid:33627652 - 32.
Zorzella-Pezavento SFG, Chiuso-Minicucci F, França TGD, Ishikawa LLW, da Rosa LC, Marques C, et al. Persistent Inflammation inside the CNS all through Chronic EAE Despite Local Absence of IL-17 Production. Mediators Inflamm. 2013;2013:519627. pmid:23970813 - 33.
Wu F, Cao W, Yang Y, Liu A. Extensive infiltration of neutrophils inside the acute phase of experimental autoimmune encephalomyelitis in C57BL/6 mice. Histochem Cell Biol. 2010;133(3):313–22. pmid:20063008 - 34.
Gudmundsson GH, Agerberth B, Odeberg J, Bergman T, Olsson B, Salcedo R. The human gene FALL39 and processing of the cathelin precursor to the antibacterial peptide LL-37 in granulocytes. Eur J Biochem. 1996;238(2):325–32. pmid:8681941 - 35.
Sørensen OE, Follin P, Johnsen AH, Calafat J, Tjabringa GS, Hiemstra PS, et al. Human cathelicidin, hCAP-18, is processed to the antimicrobial peptide LL-37 by extracellular cleavage with proteinase 3. Blood. 2001;97(12):3951–9. pmid:11389039 - 36.
Lande R, Ganguly D, Facchinetti V, Frasca L, Conrad C, Gregorio J, et al. Neutrophils activate plasmacytoid dendritic cells by releasing self-DNA-peptide complexes in systemic lupus erythematosus. Sci Transl Med. 2011;3(73):73ra19. pmid:21389263 - 37.
Dudal S, Turriere C, Bessoles S, Fontes P, Sanchez F, Liautard J, et al. Release of LL-37 by Activated Human Vγ9Vδ2 T Cells: A Microbicidal Weapon in opposition to <em>Brucella suis</em>. J Immunol. 2006;177(8):5533. - 38.
Agerberth B, Charo J, Werr J, Olsson B, Idali F, Lindbom L, et al. The human antimicrobial and chemotactic peptides LL-37 and alpha-defensins are expressed by explicit lymphocyte and monocyte populations. Blood. 2000;96(9):3086–93. pmid:11049988 - 39.
Zhang LJ, Guerrero-Juarez CF, Hata T, Bapat SP, Ramos R, Plikus MV, et al. Innate immunity. Dermal adipocytes defend in opposition to invasive Staphylococcus aureus pores and pores and skin an an infection. Science. 2015;347(6217):67–71. pmid:25554785 - 40.
Yim S, Dhawan P, Ragunath C, Christakos S, Diamond G. Induction of cathelicidin in common and CF bronchial epithelial cells by 1,25-dihydroxyvitamin D(3). J Cyst Fibros. 2007;6(6):403–10. pmid:17467345 - 41.
Bals R, Wang X, Zasloff M, Wilson JM. The peptide antibiotic LL-37/hCAP-18 is expressed in epithelia of the human lung the place it has broad antimicrobial train on the airway flooring. Proc Natl Acad Sci. 1998;95(16):9541. pmid:9689116 - 42.
Frohm Nilsson M, Sandstedt B, Sørensen O, Weber G, Borregaard N, Ståhle-Bäckdahl M. The human cationic antimicrobial protein (hCAP18), a peptide antibiotic, is broadly expressed in human squamous epithelia and colocalizes with interleukin-6. Infect Immun. 1999;67(5):2561–6. pmid:10225921 - 43.
Di Nardo A, Braff MH, Taylor KR, Na C, Granstein RD, McInturff JE, et al. Cathelicidin Antimicrobial Peptides Block Dendritic Cell TLR4 Activation and Allergic Contact Sensitization. J Immunol. 2007;178(3):1829. pmid:17237433 - 44.
Elkjaer ML, Frisch T, Reynolds R, Kacprowski T, Burton M, Kruse TA, et al. Molecular signature of assorted lesion kinds inside the thoughts white matter of victims with progressive plenty of sclerosis. Acta Neuropathol Commun. 2019;7(1):205. pmid:31829262 - 45.
Frischer JM, Weigand SD, Guo Y, Kale N, Parisi JE, Pirko I, et al. Clinical and pathological insights into the dynamic nature of the white matter plenty of sclerosis plaque. Ann Neurol. 2015;78(5):710–21. pmid:26239536 - 46.
Reynolds R, Roncaroli F, Nicholas R, Radotra B, Gveric D, Howell O. The neuropathological basis of medical growth in plenty of sclerosis. Acta Neuropathol. 2011;122(2):155–70. pmid:21626034 - 47.
Nizet V, Ohtake T, Lauth X, Trowbridge J, Rudisill J, Dorschner RA, et al. Innate antimicrobial peptide protects the pores and pores and skin from invasive bacterial an an infection. Nature. 2001;414(6862):454–7. pmid:11719807 - 48.
Orthgiess J, Gericke M, Immig Okay, Schulz A, Hirrlinger J, Bechmann I, et al. Neurons exhibit Lyz2 promoter train in vivo: Implications for using LysM-Cre mice in myeloid cell evaluation. Eur J Immunol. 2016;46 (6):1529–1532. pmid:27062494 - 49.
De Y, Chen Q, Schmidt AP, Anderson GM, Wang JM, Wooters J, et al. LL-37, the neutrophil granule- and epithelial cell-derived cathelicidin, makes use of formyl peptide receptor-like 1 (FPRL1) as a receptor to chemoattract human peripheral blood neutrophils, monocytes, and T cells. J Exp Med. 2000;192(7):1069–74. pmid:11015447 - 50.
Ghoreschi Okay, Laurence A, Yang X-P, Tato CM, McGeachy MJ, Konkel JE, et al. Generation of pathogenic TH17 cells inside the absence of TGF-β signalling. Nature. 2010;467(7318):967–71. pmid:20962846 - 51.
Zamvil S, Nelson P, Trotter J, Mitchell D, Knobler R, Fritz R, et al. T-cell clones explicit for myelin basic protein induce persistent relapsing paralysis and demyelination. Nature. 1985;317(6035):355–8. pmid:2413363 - 52.
Goverman J. Autoimmune T cell responses inside the central nervous system. Nat Rev Immunol. 2009;9(6):393–407. pmid:19444307 - 53.
Reboldi A, Coisne C, Baumjohann D, Benvenuto F, Bottinelli D, Lira S, et al. C-C chemokine receptor 6-regulated entry of TH-17 cells into the CNS by the use of the choroid plexus is required for the initiation of EAE. Nat Immunol. 2009;10(5):514–23. pmid:19305396 - 54.
Baron JL, Madri JA, Ruddle NH, Hashim G, Janeway CA Jr. Surface expression of alpha 4 integrin by CD4 T cells is required for his or her entry into thoughts parenchyma. J Exp Med. 1993;177(1):57–68. pmid:7678116 - 55.
Leonard J, Waldburger Okay, Goldman S. Prevention of experimental autoimmune encephalomyelitis by antibodies in opposition to interleukin 12. J Exp Med. 1995;181(1):381–6. pmid:7528773 - 56.
Segal BM, Shevach EM. IL-12 unmasks latent autoimmune sickness in resistant mice. J Exp Med. 1996;184(2):771–5. pmid:8786337 - 57.
Yang XO, Chang SH, Park H, Nurieva R, Shah B, Acero L, et al. Regulation of inflammatory responses by IL-17F. J Exp Med. 2008;205(5):1063–75. pmid:18411338 - 58.
Lee YK, Turner H, Maynard CL, Oliver JR, Chen D, Elson CO, et al. Late developmental plasticity inside the T helper 17 lineage. Immunity. 2009;30(1):92–107. pmid:19119024 - 59.
Lee YK, Mukasa R, Hatton RD, Weaver CT. Developmental plasticity of Th17 and Treg cells. Curr Opin Immunol. 2009;21(3):274–80. pmid:19524429 - 60.
Yang Y, Weiner J, Liu Y, Smith AJ, Huss DJ, Winger R, et al. T-bet is essential for encephalitogenicity of every Th1 and Th17 cells. J Exp Med. 2009;206(7):1549–64. pmid:19546248 - 61.
Kurschus FC, Croxford AL, Heinen AP, Wörtge S, Ielo D, Waisman A. Genetic proof for the transient nature of the Th17 phenotype. Eur J Immunol. 2010;40(12):3336–46. pmid:21110317 - 62.
Kebir H, Ifergan I, Alvarez JI, Bernard M, Poirier J, Arbour N, et al. Preferential recruitment of interferon-γ–expressing TH17 cells in plenty of sclerosis. Ann Neurol. 2009;66(3):390–402. - 63.
O’Connor RA, Prendergast CT, Sabatos CA, Lau CWZ, Leech MD, Wraith DC, et al. Cutting edge: Th1 cells facilitate the entry of Th17 cells to the central nervous system all through experimental autoimmune encephalomyelitis. J Immunol. 2008;181(6):3750–4. pmid:18768826 - 64.
Harbour SN, Maynard CL, Zindl CL, Schoeb TR, Weaver CT. Th17 cells give rise to Th1 cells which could be required for the pathogenesis of colitis. Proc Natl Acad Sci. 2015;112(22):7061–6. pmid:26038559 - 65.
Duhen R, Glatigny S, Arbelaez CA, Blair TC, Oukka M, Bettelli E. Cutting edge: The pathogenicity of IFN-γ–producing Th17 cells is neutral of T-bet. J Immunol. 2013;190(9):4478–82. pmid:23543757 - 66.
Duhen T, Campbell DJ. IL-1β promotes the differentiation of polyfunctional human CCR6+CXCR3+ Th1/17 cells which could be explicit for pathogenic and commensal microbes. J Immunol. 2014;193(1):120–9. pmid:24890729 - 67.
Takahashi T, Kulkarni NN, Lee EY, Zhang LJ, Wong GCL, Gallo RL. Cathelicidin promotes irritation by enabling binding of self-RNA to cell flooring scavenger receptors. Sci Rep. 2018;8(1):4032. pmid:29507358 - 68.
Hiemstra PS, Amatngalim GD, van der Does AM, Taube C. Antimicrobial Peptides and Innate Lung Defenses: Role in Infectious and Noninfectious Lung Diseases and Therapeutic Applications. Chest. 2016;149(2):545–51. pmid:26502035 - 69.
Lande R, Gregorio J, Facchinetti V, Chatterjee B, Wang Y-H, Homey B, et al. Plasmacytoid dendritic cells sense self-DNA coupled with antimicrobial peptide. Nature. 2007;449(7162):564–9. pmid:17873860 - 70.
Takahashi T, Gallo RL. The Critical and Multifunctional Roles of Antimicrobial Peptides in Dermatology. Dermatol Clin. 2017;35(1):39–50. pmid:27890236 - 71.
Kahlenberg JM, Kaplan MJ. Little Peptide, Big Effects: The Role of LL-37 in Inflammation and Autoimmune Disease. J Immunol. 2013;191(10):4895–901. pmid:24185823 - 72.
McHugh BJ, Wang R, Li HN, Beaumont PE, Kells R, Stevens H, et al. Cathelicidin is a “fire alarm”, producing defending NLRP3-dependent airway epithelial cell inflammatory responses all through an an infection with Pseudomonas aeruginosa. PLoS Pathog. 2019;15(4):e1007694. pmid:30978238 - 73.
Bowdish DM, Davidson DJ, Speert DP, Hancock RE. The human cationic peptide LL-37 induces activation of the extracellular signal-regulated kinase and p38 kinase pathways in main human monocytes. J Immunol. 2004;172(6):3758–65. pmid:15004180 - 74.
Nijnik A, Pistolic J, Wyatt A, Tam S, Hancock RE. Human cathelicidin peptide LL-37 modulates the results of IFN-γ on APCs. J Immunol. 2009;183(9):5788–98. - 75.
Li N, Yamasaki Okay, Saito R, Fukushi-Takahashi S, Shimada-Omori R, Asano M, et al. Alarmin carry out of cathelicidin antimicrobial peptide LL37 by the use of IL-36γ induction in human epidermal keratinocytes. J Immunol. 2014;193(10):5140–8. pmid:25305315 - 76.
Aguilar-Flores C, Castro-Escamilla O, Ortega-Rocha EM, Maldonado-García C, Jurado-Santa Cruz F, Pérez-Montesinos G, et al. Association of Pathogenic Th17 Cells with the Disease Severity and Its Potential Implication for Biological Treatment Selection in Psoriasis Patients. Mediators Inflamm. 2020;2020:8065147–. pmid:32801996 - 77.
Lowes MA, Kikuchi T, Fuentes-Duculan J, Cardinale I, Zaba LC, Haider AS, et al. Psoriasis Vulgaris Lesions Contain Discrete Populations of Th1 and Th17 T Cells. J Invest Dermatol. 2008;128(5):1207–11. pmid:18200064 - 78.
Lande R, Botti E, Jandus C, Dojcinovic D, Fanelli G, Conrad C, et al. The antimicrobial peptide LL37 is a T-cell autoantigen in psoriasis. Nature. IDAA Commun. 2014;5. pmid:25470744 - 79.
Findlay EG, Currie AJ, Zhang A, Ovciarikova J, Young L, Stevens H, et al. Exposure to the antimicrobial peptide LL-37 produces dendritic cells optimized for immunotherapy. Onco Targets Ther. 2019;8(8):1608106. - 80.
Davidson DJ, Currie AJ, Reid GS, Bowdish DM, MacDonald KL, Ma RC, et al. The cationic antimicrobial peptide LL-37 modulates dendritic cell differentiation and dendritic cell-induced T cell polarization. J Immunol. 2004;172(2):1146–56. pmid:14707090 - 81.
Hertwig L, Pache F, Romero-Suarez S, Stürner KH, Borisow N, Behrens J, et al. Distinct efficiency of neutrophils in plenty of sclerosis and neuromyelitis optica. Mult Scler. 2016;22(2):160–73. pmid:26540731 - 82.
Saadoun S, Waters P, MacDonald C, Bell BA, Vincent A, Verkman AS, et al. Neutrophil protease inhibition reduces neuromyelitis optica-immunoglobulin G-induced hurt in mouse thoughts. Ann Neurol. 2012;71(3):323–33. pmid:22374891 - 83.
Li Y, Wang H, Long Y, Lu Z, Hu X. Increased memory Th17 cells in victims with neuromyelitis optica and plenty of sclerosis. J Neuroimmunol. 2011;234(1–2):155–160. pmid:21489641 - 84.
Linhares UC, Schiavoni PB, Barros PO, Kasahara TM, Teixeira B, Ferreira TB, et al. The ex vivo manufacturing of IL-6 and IL-21 by CD4+ T cells is straight away associated to neurological incapacity in neuromyelitis optica victims. J Clin Immunol. 2013;33(1):179–89. pmid:22948743 - 85.
Seiderer J, Elben I, Diegelmann J, Glas J, Stallhofer J, Tillack C, et al. Role of the novel Th17 cytokine IL-17F in inflammatory bowel sickness (IBD): upregulated colonic IL-17F expression in energetic Crohn’s sickness and analysis of the IL17F p. His161Arg polymorphism in IBD. Inflamm Bowel Dis. 2008;14(4):437–45. pmid:18088064 - 86.
Therrien A, Chapuy L, Bsat M, Rubio M, Bernard G, Arslanian E, et al. Recruitment of activated neutrophils correlates with sickness severity in grownup Crohn’s sickness. Clin Exp Immunol. 2019;195(2):251–64. pmid:30347439 - 87.
Bergman P, Termén S, Johansson L, Nyström L, Arenas E, Jonsson AB, et al. The antimicrobial peptide rCRAMP is present inside the central nervous system of the rat. J Neurochem. 2005;93(5):1132–40. pmid:15934934 - 88.
Wan M, Sabirsh A, Wetterholm A, Agerberth B, Haeggström JZ. Leukotriene B4 triggers launch of the cathelicidin LL-37 from human neutrophils: novel lipid-peptide interactions in innate immune responses. FASEB J. 2007;21(11):2897–905. pmid:17446260 - 89.
Kulkarni NN, Yi Z, Huehnken C, Agerberth B, Gudmundsson GH. Phenylbutyrate induces cathelicidin expression by the use of the vitamin D receptor: Linkage to inflammatory and progress subject cytokines pathways. Mol Immunol. 2015;63(2):530–9. pmid:25458314 - 90.
Bergman P, Johansson L, Wan H, Jones A, Gallo RL, Gudmundsson GH, et al. Induction of the antimicrobial peptide CRAMP inside the blood-brain barrier and meninges after meningococcal an an infection. Infect Immun. 2006;74(12):6982–91. pmid:17030578 - 91.
Xu X, Cai X, Zhu Y, He W, Wu Q, Shi X, et al. MFG-E8 inhibits Aβ-induced microglial manufacturing of cathelicidin-related antimicrobial peptide: An acceptable aim in opposition to Alzheimer’s sickness. Cell Immunol. 2018;331:59–66. pmid:29861070 - 92.
Brandenburg LO, Varoga D, Nicolaeva N, Leib SL, Wilms H, Podschun R, et al. Role of glial cells inside the purposeful expression of LL-37/rat cathelin-related antimicrobial peptide in meningitis. J Neuropathol Exp Neurol. 2008;67(11):1041–54. pmid:18957897 - 93.
Lee M, Shi X, Barron AE, McGeer E, McGeer PL. Human antimicrobial peptide LL-37 induces glial-mediated neuroinflammation. Biochem Pharmacol. 2015;94(2):130–41. pmid:25686659 - 94.
Parodi B, Kerlero de Rosbo N. The Gut-Brain Axis in Multiple Sclerosis. Is Its Dysfunction a Pathological Trigger or a Consequence of the Disease? Front Immunol. 2021;12. pmid:34621267 - 95.
Liang W, Enée E, Andre-Vallee C, Falcone M, Sun J, Diana J. Intestinal Cathelicidin Antimicrobial Peptide Shapes a Protective Neonatal Gut Microbiota Against Pancreatic Autoimmunity. Gastroenterology. 2022;162(4):1288–302.e16. pmid:34973295 - 96.
Bescucci DM, Clarke ST, Brown CLJ, Boras VF, Montina T, Uwiera RRE, et al. The absence of murine cathelicidin-related antimicrobial peptide impacts host responses enhancing Salmonella enterica serovar Typhimurium an an infection. Gut Pathogens. 2020;12(1):53. pmid:33292444