scholarly journals Negative regulation of autoimmune demyelination by the inhibitory receptor CLM-1

2009 ◽  
Vol 207 (1) ◽  
pp. 7-16 ◽  
Author(s):  
Hongkang Xi ◽  
Kenneth J. Katschke ◽  
Karim Y. Helmy ◽  
Paige A. Wark ◽  
Noelyn Kljavin ◽  
...  

Multiple sclerosis and its preclinical model, experimental autoimmune encephalomyelitis, are marked by perivascular inflammation and demyelination. Myeloid cells, derived from circulating progenitors, are a prominent component of the inflammatory infiltrate and are believed to directly contribute to demyelination and axonal damage. How the cytotoxic activity of these myeloid cells is regulated is poorly understood. We identify CMRF-35–like molecule-1 (CLM-1) as a negative regulator of autoimmune demyelination. CLM-1 is expressed on inflammatory myeloid cells present in demyelinating areas of the spinal cord after immunization of mice with MOG35-55 (myelin oligodendrocyte glycoprotein) peptide. Absence of CLM-1 resulted in significantly increased nitric oxide and proinflammatory cytokine production, along with increased demyelination and worsened clinical scores, whereas T cell responses in the periphery or in the spinal cord remained unaffected. This study thus identifies CLM-1 as a negative regulator of myeloid effector cells in autoimmune demyelination.

2020 ◽  
Vol 117 (4) ◽  
pp. 2160-2169 ◽  
Author(s):  
Yinan Zhao ◽  
Ryo Yamasaki ◽  
Hiroo Yamaguchi ◽  
Satoshi Nagata ◽  
Hayato Une ◽  
...  

In multiple sclerosis plaques, oligodendroglial connexin (Cx) 47 constituting main gap junction channels with astroglial Cx43 is persistently lost. As mice with Cx47 single knockout exhibit no demyelination, the roles of Cx47 remain undefined. We aimed to clarify the effects of oligodendroglia-specific Cx47 inducible conditional knockout (icKO) on experimental autoimmune encephalomyelitis (EAE) induced by myelin oligodendrocyte glycoprotein peptide (MOG35-55) in PLP/CreERT;Cx47fl/fl mice at 14 d after tamoxifen injection. Cx47 icKO mice demonstrated exacerbation of acute and chronic relapsing EAE with more pronounced demyelination than Cx47 flox (fl)/fl littermates. CD3+ T cells more abundantly infiltrated the spinal cord in Cx47 icKO than in Cx47 fl/fl mice throughout the acute to chronic phases. CXCR3-CCR6+CD4+ and IL17+IFNγ-CD4+ helper T (Th) 17 cells isolated from spinal cord and brain tissues were significantly increased in Cx47 icKO mice compared with Cx47 fl/fl mice, while MOG35-55-specific proliferation and proinflammatory cytokine production of splenocytes were unaltered. Microarray analysis of isolated microglia revealed stronger microglial activation toward proinflammatory and injury-response phenotypes with increased expressions of chemokines that can attract Th17 cells, including Ccl2, Ccl3, Ccl4, Ccl7, and Ccl8, in Cx47 icKO mice compared with Cx47 fl/fl mice. In Cx47 icKO mice, NOS2+ and MHC class II+ microglia were more enriched immunohistochemically, and A1-specific astroglial gene expressions and astroglia immunostained for C3, a representative A1 astrocyte marker, were significantly increased at the acute phase, compared with Cx47 fl/fl mice. These findings suggest that oligodendroglia-specific Cx47 ablation induces severe inflammation upon autoimmune demyelination, underscoring a critical role for Cx47 in regulating neuroinflammation.


2018 ◽  
Vol 115 (6) ◽  
pp. E1194-E1203 ◽  
Author(s):  
Alexandre Paré ◽  
Benoit Mailhot ◽  
Sébastien A. Lévesque ◽  
Camille Juzwik ◽  
Prenitha Mercy Ignatius Arokia Doss ◽  
...  

Molecular interventions that limit pathogenic CNS inflammation are used to treat autoimmune conditions such as multiple sclerosis (MS). Remarkably, IL-1β–knockout mice are highly resistant to experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Here, we show that interfering with the IL-1β/IL-1R1 axis severely impairs the transmigration of myeloid cells across central nervous system (CNS) endothelial cells (ECs). Notably, we report that IL-1β expression by inflammatory CCR2hi monocytes favors their entry into the spinal cord before EAE onset. Following activation with IL-1β, CNS ECs release GM-CSF, which in turn converts monocytes into antigen-presenting cells (APCs). Accordingly, spinal cord-infiltrated monocyte-derived APCs are associated with dividing CD4+ T cells. Factors released from the interaction between IL-1β–competent myeloid cells and CD4+ T cells are highly toxic to neurons. Together, our results suggest that IL-1β signaling is an entry point for targeting both the initiation and exacerbation of neuroinflammation.


2022 ◽  
Vol 12 ◽  
Author(s):  
Yanis Feraoun ◽  
Jean-Louis Palgen ◽  
Candie Joly ◽  
Nicolas Tchitchek ◽  
Ernesto Marcos-Lopez ◽  
...  

Innate immunity modulates adaptive immunity and defines the magnitude, quality, and longevity of antigen-specific T- and B- cell immune memory. Various vaccine and administration factors influence the immune response to vaccination, including the route of vaccine delivery. We studied the dynamics of innate cell responses in blood using a preclinical model of non-human primates immunized with a live attenuated vaccinia virus, a recombinant Modified vaccinia virus Ankara (MVA) expressing a gag-pol-nef fusion of HIV-1, and mass cytometry. We previously showed that it induces a strong, early, and transient innate response, but also late phenotypic modifications of blood myeloid cells after two months when injected subcutaneously. Here, we show that the early innate effector cell responses and plasma inflammatory cytokine profiles differ between subcutaneous and intradermal vaccine injection. Additionally, we show that the intradermal administration fails to induce more highly activated/mature neutrophils long after immunization, in contrast to subcutaneous administration. Different batches of antibodies, staining protocols and generations of mass cytometers were used to generate the two datasets. Mass cytometry data were analyzed in parallel using the same analytical pipeline based on three successive clustering steps, including SPADE, and categorical heatmaps were compared using the Manhattan distance to measure the similarity between cell cluster phenotypes. Overall, we show that the vaccine per se is not sufficient for the late phenotypic modifications of innate myeloid cells, which are evocative of innate immune training. Its route of administration is also crucial, likely by influencing the early innate response, and systemic inflammation, and vaccine biodistribution.


2019 ◽  
Vol 26 (3) ◽  
pp. 294-303 ◽  
Author(s):  
Cassandra E Meyer ◽  
Josephine L Gao ◽  
James Ying-Jie Cheng ◽  
Mandavi R Oberoi ◽  
Hadley Johnsonbaugh ◽  
...  

Background: Gray matter (GM) atrophy in brain is one of the best predictors of long-term disability in multiple sclerosis (MS), and recent findings have revealed that localized GM atrophy is associated with clinical disabilities. GM atrophy associated with each disability mapped to a distinct brain region, revealing a disability-specific atlas (DSA) of GM loss. Objective: To uncover the mechanisms underlying the development of localized GM atrophy. Methods: We used voxel-based morphometry (VBM) to evaluate localized GM atrophy and Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging-compatible Tissue-hYdrogel (CLARITY) to evaluate specific pathologies in mice with experimental autoimmune encephalomyelitis (EAE). Results: We observed extensive GM atrophy throughout the cerebral cortex, with additional foci in the thalamus and caudoputamen, in mice with EAE compared to normal controls. Next, we generated pathology-specific atlases (PSAs), voxelwise mappings of the correlation between specific pathologies and localized GM atrophy. Interestingly, axonal damage (end-bulbs and ovoids) in the spinal cord strongly correlated with GM atrophy in the sensorimotor cortex of the brain. Conclusion: The combination of VBM with CLARITY in EAE can localize GM atrophy in brain that is associated with a specific pathology in spinal cord, revealing a PSA of GM loss.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shaona Acharjee ◽  
Paul M. K. Gordon ◽  
Benjamin H. Lee ◽  
Justin Read ◽  
Matthew L. Workentine ◽  
...  

AbstractMicroglia play an important role in the pathogenesis of multiple sclerosis and the mouse model of MS, experimental autoimmune encephalomyelitis (EAE). To more fully understand the role of microglia in EAE we characterized microglial transcriptomes before the onset of motor symptoms (pre-onset) and during symptomatic EAE. We compared the transcriptome in brain, where behavioral changes are initiated, and spinal cord, where damage is revealed as motor and sensory deficits. We used a RiboTag strategy to characterize ribosome-bound mRNA only in microglia without incurring possible transcriptional changes after cell isolation. Brain and spinal cord samples clustered separately at both stages of EAE, indicating regional heterogeneity. Differences in gene expression were observed in the brain and spinal cord of pre-onset and symptomatic animals with most profound effects in the spinal cord of symptomatic animals. Canonical pathway analysis revealed changes in neuroinflammatory pathways, immune functions and enhanced cell division in both pre-onset and symptomatic brain and spinal cord. We also observed a continuum of many pathways at pre-onset stage that continue into the symptomatic stage of EAE. Our results provide additional evidence of regional and temporal heterogeneity in microglial gene expression patterns that may help in understanding mechanisms underlying various symptomology in MS.


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