MHC-II peptidome of the CNS reveals endogenous guardian peptides
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Fusion Lumos
ORGANISM(S): Mus Musculus (ncbitaxon:10090)
SUBMITTER: 
Jonathan Kipnis
PROVIDER: MSV000092643 | MassIVE | Fri Aug 11 14:18:00 BST 2023
SECONDARY ACCESSION(S): PXD044518
REPOSITORIES: MassIVE
Similar Datasets
Project description:The central nervous system (CNS), despite the presence of strategically positioned anatomical barriers designed to protect it, is not entirely isolated from the immune system. In fact, it remains physically connected to and can be influenced by the peripheral immune system. How the CNS retains such responsiveness while maintaining “immune privilege” remains an outstanding conundrum. In searching for molecular cues that derive from the CNS and allow its direct communication with the immune system, we discovered a repertoire of CNS-derived endogenous guardian peptides presented on major histocompatibility complex (MHC) II molecules at the CNS borders. During homeostasis, a preponderance of these guardian peptides were found to be bound to MHC II molecules throughout the path of lymphatic drainage from the brain to its surrounding meninges and its draining cervical lymph nodes. With neuroinflammatory disease, however, the presentation of guardian peptides was diminished. Fascinatingly, boosting the presence of these guardian peptides reinforced a population of suppressor CD4+ T cells and significantly reduced CNS autoimmune disease. This unexpected discovery of CNS-derived autoimmune guardian peptides may be the molecular key adapting the CNS to receive information and to maintain continuous dialogue with the immune system while balancing overt autoreactivity. This sheds new light on how we conceptually think about and therapeutically target neuroinflammatory and neurodegenerative diseases.
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Project description:MHC-II peptidome of the CNS reveals endogenous guardian peptides
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Project description:The central nervous system (CNS), despite the presence of strategically positioned anatomical barriers designed to protect it, is not entirely isolated from the immune system1,2. In fact, it remains physically connected to and can be influenced by the peripheral immune system. How the CNS retains such responsiveness while maintaining an immunologically unique status remains an outstanding conundrum. In searching for molecular cues that derive from the CNS and allow its direct communication with the immune system, we discovered a repertoire of CNS-derived endogenous regulatory self-peptides presented on major histocompatibility complex (MHC) II molecules at the CNS borders. During homeostasis, a preponderance of these regulatory self-peptides were found to be bound to MHC II molecules throughout the path of lymphatic drainage from the brain to its surrounding meninges and its draining cervical lymph nodes. With neuroinflammatory disease, however, the presentation of regulatory self-peptides diminished. Upon boosting the presentation of these regulatory self-peptides, a population of suppressor CD4+ T cells could be expanded, controlling CNS autoimmunity in a CTLA-4 and TGF dependent manner. This unexpected discovery of CNS-derived autoimmune self-peptides may be the molecular key adapting the CNS to maintain continuous dialogue with the immune system while balancing overt autoreactivity. This sheds new light on how we conceptually think about and therapeutically target neuroinflammatory and neurodegenerative diseases.
2024-10-11 | GSE272901 | GEO
Project description:The central nervous system (CNS), despite the presence of strategically positioned anatomical barriers designed to protect it, is not entirely isolated from the immune system1,2. In fact, it remains physically connected to and can be influenced by the peripheral immune system. How the CNS retains such responsiveness while maintaining an immunologically unique status remains an outstanding conundrum. In searching for molecular cues that derive from the CNS and allow its direct communication with the immune system, we discovered a repertoire of CNS-derived endogenous regulatory self-peptides presented on major histocompatibility complex (MHC) II molecules at the CNS borders. During homeostasis, a preponderance of these regulatory self-peptides were found to be bound to MHC II molecules throughout the path of lymphatic drainage from the brain to its surrounding meninges and its draining cervical lymph nodes. With neuroinflammatory disease, however, the presentation of regulatory self-peptides diminished. Upon boosting the presentation of these regulatory self-peptides, a population of suppressor CD4+ T cells could be expanded, controlling CNS autoimmunity in a CTLA-4 and TGF dependent manner. This unexpected discovery of CNS-derived autoimmune self-peptides may be the molecular key adapting the CNS to maintain continuous dialogue with the immune system while balancing overt autoreactivity. This sheds new light on how we conceptually think about and therapeutically target neuroinflammatory and neurodegenerative diseases.
2024-10-11 | GSE273051 | GEO
Project description:The central nervous system (CNS), despite the presence of strategically positioned anatomical barriers designed to protect it, is not entirely isolated from the immune system1,2. In fact, it remains physically connected to and can be influenced by the peripheral immune system. How the CNS retains such responsiveness while maintaining an immunologically unique status remains an outstanding conundrum. In searching for molecular cues that derive from the CNS and allow its direct communication with the immune system, we discovered a repertoire of CNS-derived endogenous regulatory self-peptides presented on major histocompatibility complex (MHC) II molecules at the CNS borders. During homeostasis, a preponderance of these regulatory self-peptides were found to be bound to MHC II molecules throughout the path of lymphatic drainage from the brain to its surrounding meninges and its draining cervical lymph nodes. With neuroinflammatory disease, however, the presentation of regulatory self-peptides diminished. Upon boosting the presentation of these regulatory self-peptides, a population of suppressor CD4+ T cells could be expanded, controlling CNS autoimmunity in a CTLA-4 and TGF dependent manner. This unexpected discovery of CNS-derived autoimmune self-peptides may be the molecular key adapting the CNS to maintain continuous dialogue with the immune system while balancing overt autoreactivity. This sheds new light on how we conceptually think about and therapeutically target neuroinflammatory and neurodegenerative diseases.
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Project description:In homeostasis, because of the blood-brain barrier, immune cells rarely infiltrate the central nervous system (CNS). However, after spinal cord injury (SCI), many cells, including both myeloid and T cells, infiltrate the spinal cord. However, the role immune cells play in SCI remains controversial. We are curious whether after SCI there are self-peptides that are released and sensed by T cells that then modulate response to CNS injury.
2023-01-24 | MSV000091130 | MassIVE
Project description:The nature of autoantigens that trigger autoimmune diseases has been much discussed but direct biochemical identification is lacking for most. Addressing this question demands unbiased examination of the self-peptides displayed by a defined autoimmune MHC-II molecule. We have examined the immunopeptidome of the pancreatic islets of the NOD mouse that spontaneously develops autoimmune diabetes based on its MHC-II, the I-Ag7 variant. The relevant peptides that induced early CD4 T cells derived from insulin and C-peptide; these were also found in the MHC-II peptidome of the pancreatic lymph node and spleen. The insulin-derived peptides followed a trajectory from internal processing in beta cells to exocytosis, uptake, and presentation in islets and peripheral sites. Such process not only generated conventional epitopes but also resulted in presentation of post-translationally modified peptides, including deamidated and fused sequences. These analyses reveal the key features of a restricted component in the self-MHC-II peptidome causing autoreactivity.
2020-03-12 | PXD015408 | Pride
Project description:The nature of autoantigens that trigger autoimmune diseases has been much discussed, but direct biochemical identification is lacking for most. Addressing this question demands unbiased examination of the self-peptides displayed by a defined autoimmune major histocompatibility complex class II (MHC-II) molecule. Here, we examined the immunopeptidome of the pancreatic islets in non-obese diabetic mice, which spontaneously develop autoimmune diabetes based on the I-Ag7 variant of MHC-II. The relevant peptides that induced pathogenic CD4+ T cells at the initiation of diabetes derived from proinsulin. These peptides were also found in the MHC-II peptidome of the pancreatic lymph nodes and spleen. The proinsulin-derived peptides followed a trajectory from their generation and exocytosis in ? cells to uptake and presentation in islets and peripheral sites. Such a pathway generated conventional epitopes but also resulted in the presentation of post-translationally modified peptides, including deamidated sequences. These analyses reveal the key features of a restricted component in the self-MHC-II peptidome that caused autoreactivity.
| S-EPMC7117798 | biostudies-literature
Project description:Assessing the self-peptides presented by susceptible major histocompatibility complex (MHC) molecules is crucial for evaluating the pathogenesis and therapeutics of tissue-specific autoimmune diseases. However, direct examination of such MHC-bound peptides displayed in the target organ remains largely impractical. Here, we demonstrate that the blood leukocytes from non-obese diabetic (NOD) mice presented peptide epitopes to autoreactive CD4 T cells. These peptides were bound to the autoimmune class II MHC molecule, I-Ag7, and originated from insulin B-chain and C-peptide. The presentation required a glucose challenge, which stimulated the release of insulin peptides from pancreatic islets. The circulating leukocytes, especially the B cells, promptly captured and presented these peptides. Although canonical intracellular processing of insulin was involved in the presentation, extracellular binding of catabolized insulin products to I-Ag7 gave rise to a unique pathogenic epitope. Administration of monoclonal antibodies recognizing insulin B-chain abolished the presentation and diminished diabetes incidence. Mass spectrometry analysis of the leukocyte MHC-II peptidomes revealed a series of beta cell derived peptides, with identical sequences to those previously in the islet MHC-II peptidome. Thus, the WBC peptidome echoes that found in islets and serves to identify immunogenic peptides in an otherwise inaccessible tissue.
2021-03-26 | PXD024400 | Pride
Project description:We previously reported that a synthetic Nod1 ligand, FK565, induced coronary arteritis in mice similar to Kawasaki disease. However, the molecular mechanisms underlying this site-specific inflammation have remained elusive. In this study, we found that CD11c+MHC class II+ cells accumulated in the heart of FK565-treated mice prior to arteritis development. We used microarray analysis to detail gene expression of CD11c+MHC class II+ cells. To obtain gene expression profile of CD11c+MHC class II+ cells, we isolated these cells from hearts of FK565-treated mice. Briefly, female mice at 8weeks age were administered 500 μg of FK565 subcutaneously at day 0 and day 3. At day6, murine hearts were removed and digested with collagenase. CD11c+MHC II+ cells were sorted as PI–CD45+Ly6G–NK1.1–CD11b+CD11c+MHC II+ using FACS Aria cell sorter (BD Biosciences). Sorted cells were subjected to RNA preparation. Two independent replicates from ten mice were made.
2015-03-31 | E-GEOD-60506 | biostudies-arrayexpress