Autonomous TNF is critical for in vivo monocyte survival in steady state and inflammation

Monocytes are circulating mononuclear phagocytes, poised to extravasate to sites of inflammation and differentiate into monocyte-derived macrophages and dendritic cells. Tumor necrosis factor (TNF) and its receptors are up-regulated during monopoiesis and expressed by circulating monocytes, as well as effector monocytes infiltrating certain sites of inflammation, such as the spinal cord, during experimental autoimmune encephalomyelitis (EAE). In this study, using competitive in vitro and in vivo assays, we show that monocytes deficient for TNF or TNF receptors are outcompeted by their wild-type counterpart. Moreover, monocyte-autonomous TNF is critical for the function of these cells, as TNF ablation in monocytes/macrophages, but not in microglia, delayed the onset of EAE in challenged animals and was associated with reduced acute spinal cord infiltration of Ly6Chi effector monocytes. Collectively, our data reveal a previously unappreciated critical cell-autonomous role of TNF on monocytes for their survival, maintenance, and function.

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Multiple Sclerosis CD49d+CD154+ As Myelin-Specific Lymphocytes Induced During Remyelination

Cells ◽

10.3390/cells9010015 ◽

2019 ◽

Vol 9 (1) ◽

pp. 15

Author(s):

Paweł Piatek ◽

Magdalena Namiecinska ◽

Małgorzata Domowicz ◽

Marek Wieczorek ◽

Sylwia Michlewska ◽

...

Keyword(s):

Multiple Sclerosis ◽

Cumulative Effect ◽

Autoimmune Encephalomyelitis ◽

The Central Nervous System ◽

Cns Demyelination ◽

The Brain ◽

Experimental Autoimmune

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system (CNS) mediated by autoreactive lymphocytes. The role of autoreactive lymphocytes in the CNS demyelination is well described, whereas very little is known about their role in remyelination during MS remission. In this study, we identified a new subpopulation of myelin-specific CD49d+CD154+ lymphocytes presented in the peripheral blood of MS patients during remission, that proliferated in vitro in response to myelin peptides. These lymphocytes possessed the unique ability to migrate towards maturing oligodendrocyte precursor cells (OPCs) and synthetize proinflammatory chemokines/cytokines. The co-culture of maturing OPCs with myelin-specific CD49d+CD154+ lymphocytes was characterized by the increase in proinflammatory chemokine/cytokine secretion that was not only a result of their cumulative effect of what OPCs and CD49d+CD154+ lymphocytes produced alone. Moreover, maturing OPCs exposed to exogenous myelin peptides managed to induce CD40-CD154-dependent CD49d+CD154+ lymphocyte proliferation. We confirmed, in vivo, the presence of CD49d+CD154+ cells close to maturating OPCs and remyelinating plaque during disease remission in the MS mouse model (C57Bl/6 mice immunized with MOG35-55) by immunohistochemistry. Three weeks after an acute phase of experimental autoimmune encephalomyelitis, CD49d+/CD154+ cells were found to be co-localized with O4+ cells (oligodendrocyte progenitors) in the areas of remyelination identified by myelin basic protein (MBP) labelling. These data suggested that myelin-specific CD49d+CD154+ lymphocytes present in the brain can interfere with remyelination mediated by oligodendrocytes probably as a result of establishing proinflammatory environment.

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c-Jun N-Terminal Kinase as a Therapeutic Target in Experimental Autoimmune Encephalomyelitis

Cells ◽

10.3390/cells9102154 ◽

2020 ◽

Vol 9 (10) ◽

pp. 2154

Author(s):

Maud Bagnoud ◽

Myriam Briner ◽

Jana Remlinger ◽

Ivo Meli ◽

Sara Schuetz ◽

...

Keyword(s):

Spinal Cord ◽

T Cells ◽

Experimental Autoimmune Encephalomyelitis ◽

Immune Cell ◽

Disease Onset ◽

Autoimmune Encephalomyelitis ◽

Necrosis Factor Alpha ◽

Experimental Autoimmune

c-Jun N-terminal kinase (JNK) is upregulated during multiple sclerosis relapses and at the peak of experimental autoimmune encephalomyelitis (EAE). We aim to investigate the effects of pharmacological pan-JNK inhibition on the course of myelin oligodendrocyte glycoprotein (MOG35-55) EAE disease using in vivo and in vitro experimental models. EAE was induced in female C57BL/6JRj wild type mice using MOG35-55. SP600125 (SP), a reversible adenosine triphosphate competitive pan-JNK inhibitor, was then given orally after disease onset. Positive correlation between SP plasma and brain concentration was observed. Nine, but not three, consecutive days of SP treatment led to a significant dose-dependent decrease of mean cumulative MOG35-55 EAE severity that was associated with increased mRNA expression of interferon gamma (INF-γ) and tumor necrosis factor alpha (TNF-α) in the spinal cord. On a histological level, reduced spinal cord immune cell-infiltration predominantly of CD3+ T cells as well as increased activity of Iba1+ cells were observed in treated animals. In addition, in vitro incubation of murine and human CD3+ T cells with SP resulted in reduced T cell apoptosis and proliferation. In conclusion, our study demonstrates that pharmacological pan-JNK inhibition might be a treatment strategy for autoimmune central nervous system demyelination.

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The survival and function of IL-10-producing regulatory B cells are negatively controlled by SLAMF5

Nature Communications ◽

10.1038/s41467-021-22230-z ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Lihi Radomir ◽

Matthias P. Kramer ◽

Michal Perpinial ◽

Nofar Schottlender ◽

Stav Rabani ◽

...

Keyword(s):

B Cells ◽

Autoimmune Encephalomyelitis ◽

Regulatory B Cell ◽

The Central Nervous System ◽

Factor C ◽

And Function ◽

Human And Mouse ◽

Experimental Autoimmune

AbstractB cells have essential functions in multiple sclerosis and in its mouse model, experimental autoimmune encephalomyelitis, both as drivers and suppressors of the disease. The suppressive effects are driven by a regulatory B cell (Breg) population that functions, primarily but not exclusively, via the production of IL-10. However, the mechanisms modulating IL-10-producing Breg abundance are poorly understood. Here we identify SLAMF5 for controlling IL-10+ Breg maintenance and function. In EAE, the deficiency of SLAMF5 in B cells causes accumulation of IL10+ Bregs in the central nervous system and periphery. Blocking SLAMF5 in vitro induces both human and mouse IL-10-producing Breg cells and increases their survival with a concomitant increase of a transcription factor, c-Maf. Finally, in vivo SLAMF5 blocking in EAE elevates IL-10+ Breg levels and ameliorates disease severity. Our results suggest that SLAMF5 is a negative moderator of IL-10+ Breg cells, and may serve as a therapeutic target in MS and other autoimmune diseases.

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Hormones in experimental autoimmune encephalomyelitis (EAE) animal models

Translational Neuroscience ◽

10.1515/tnsci-2020-0169 ◽

2021 ◽

Vol 12 (1) ◽

pp. 164-189

Author(s):

Majid Ghareghani ◽

Amir Ghanbari ◽

Ali Eid ◽

Abdullah Shaito ◽

Wael Mohamed ◽

...

Keyword(s):

Experimental Autoimmune Encephalomyelitis ◽

Demyelinating Disease ◽

Endocrine System ◽

Laboratory Animals ◽

Autoimmune Encephalomyelitis ◽

Eae Model ◽

Experimental Autoimmune

Abstract Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) in which activated immune cells attack the CNS and cause inflammation and demyelination. While the etiology of MS is still largely unknown, the interaction between hormones and the immune system plays a role in disease progression, but the mechanisms by which this occurs are incompletely understood. Several in vitro and in vivo experimental, but also clinical studies, have addressed the possible role of the endocrine system in susceptibility and severity of autoimmune diseases. Although there are several demyelinating models, experimental autoimmune encephalomyelitis (EAE) is the oldest and most commonly used model for MS in laboratory animals which enables researchers to translate their findings from EAE into human. Evidences imply that there is great heterogeneity in the susceptibility to the induction, the method of induction, and the response to various immunological or pharmacological interventions, which led to conflicting results on the role of specific hormones in the EAE model. In this review, we address the role of endocrine system in EAE model to provide a comprehensive view and a better understanding of the interactions between the endocrine and the immune systems in various models of EAE, to open up a ground for further detailed studies in this field by considering and comparing the results and models used in previous studies.

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Arsenic trioxide ameliorates experimental autoimmune encephalomyelitis in C57BL/6 mice through inducing apoptosis of CD4+ T cells

10.21203/rs.2.21122/v2 ◽

2020 ◽

Author(s):

Ke An ◽

Mengjiao Xue ◽

Jiaying Zhong ◽

Shengnan Yu ◽

Zhongquan Qi ◽

...

Keyword(s):

Spinal Cord ◽

T Cells ◽

Experimental Autoimmune Encephalomyelitis ◽

Arsenic Trioxide ◽

Microglia Activation ◽

Autoimmune Encephalomyelitis ◽

Post Immunization ◽

Experimental Autoimmune

Abstract Background: Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system characterized by severe demyelination of white matter. There is no definite cure for MS owing to its complex pathogenesis. Experimental autoimmune encephalomyelitis (EAE) is an ideal animal model for the study of MS. Arsenic trioxide (ATO) is an ancient Chinese medicine used for its therapeutic properties for several autoimmune diseases. It is also used to inhibit acute immune rejection due to its anti-inflammatory and immunosuppressive properties. However, it is unclear whether ATO has a therapeutic effect on EAE, and the underlying mechanisms have not been clearly elucidated. In this study, we attempted to explore the possibility of using ATO to ameliorate EAE in mice.Methods: ATO (0.5 mg/kg/day) was administered intraperitoneally to EAE mice 10 days post-immunization for 8 days. On day 22 post-immunization, the spinal cord, spleen, and blood were collected to analyze demyelination, inflammation, microglia activation, and proportion of CD4+ T cells. In vitro, for mechanistic studies, CD4+ T cells were sorted from the spleen of naïve C57BL/6 mice and treated with ATO and then used for apoptosis assay, JC-1 staining, transmission electron microscope, and western blotting.Results: ATO delayed the onset of EAE and alleviated the severity of EAE in mice. Treatment with ATO also attenuated demyelination, alleviated inflammation, reduced microglia activation and decreased the expression of IL-2, IFN-γ, IL-1β, IL-6, and TNF-α in EAE mice. Moreover, the number and proportion of CD4+ T cells in the spinal cord, spleen, and peripheral blood were reduced in ATO-treated EAE mice. Finally, ATO induced CD4+ T cells apoptosis through the mitochondrial pathway both in vitro and in vivo. Additionally, the administration of ATO had no adverse effect on the heart, liver, and kidney function and did not induce apoptosis in the spinal cord.Conclusions: Overall, our findings indicated that ATO plays a protective role in the initiation and progression of EAE and has the potential to be a novel drug in the treatment of MS.

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Toll-like receptor-9 stimulated plasmacytoid dendritic cell precursors suppress autoimmune neuroinflammation in a murine model of multiple sclerosis

Scientific Reports ◽

10.1038/s41598-021-84023-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hélène Letscher ◽

Viviane A. Agbogan ◽

Sarantis Korniotis ◽

Pauline Gastineau ◽

Emmanuel Tejerina ◽

...

Keyword(s):

Dendritic Cell ◽

Plasmacytoid Dendritic Cell ◽

Toll Like Receptor ◽

Hematopoietic Progenitors ◽

Autoimmune Encephalomyelitis ◽

Hematopoietic Precursor ◽

Therapeutic Properties ◽

Experimental Autoimmune

AbstractEarly innate education of hematopoietic progenitors within the bone marrow (BM) stably primes them for either trained immunity or instead immunoregulatory functions. We herein demonstrate that in vivo or in vitro activation within the BM via Toll-like receptor-9 generates a population of plasmacytoid dendritic cell (pDC) precursors (CpG-pre-pDCs) that, unlike pDC precursors isolated from PBS-incubated BM (PBS-pre-pDCs), are endowed with the capacity to halt progression of ongoing experimental autoimmune encephalomyelitis. CpG activation enhances the selective migration of pDC precursors to the inflamed spinal cord, induces their immediate production of TGF-β, and after migration, of enhanced levels of IL-27. CpG-pre-pDC derived TGF-β and IL-27 ensure protection at early and late phases of the disease, respectively. Spinal cords of CpG-pre-pDC-protected recipient mice display enhanced percentages of host-derived pDCs expressing TGF-β as well as an accumulation of IL-10 producing B cells and of CD11c+ CD11b+ dendritic cells. These results reveal that pDC precursors are conferred stable therapeutic properties by early innate activation within the BM. They further extend to the pDC lineage promising perspectives for cell therapy of autoimmune diseases with innate activated hematopoietic precursor cells.

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Experimental autoimmune encephalomyelitis-induced upregulation of tumor necrosis factor-alpha in the dorsal root ganglia

Multiple Sclerosis Journal ◽

10.1177/1352458509106856 ◽

2009 ◽

Vol 15 (10) ◽

pp. 1135-1145 ◽

Cited By ~ 17

Author(s):

M. Melanson ◽

P. Miao ◽

D. Eisenstat ◽

Y. Gong ◽

X. Gu ◽

...

Keyword(s):

Spinal Cord ◽

Tumor Necrosis Factor ◽

Inflammatory Cytokines ◽

Dorsal Root ◽

Tumor Necrosis ◽

Autoimmune Encephalomyelitis ◽

Necrosis Factor Alpha ◽

Factor Alpha ◽

Necrosis Factor ◽

Experimental Autoimmune

Background: Multiple sclerosis (MS) is a chronic, neurological disease characterized by targeted destruction of central nervous system (CNS) myelin. The autoimmune theory is the most widely accepted explanation of disease pathology. Circulating Th1 cells become activated by exposure to CNS-specific antigens such as myelin basic protein. The activated Th1 cells secrete inflammatory cytokines, which are pivotal for inflammatory responses. We hypothesize that enhanced production of inflammatory cytokines triggers cellular events within the dorsal root ganglia (DRG) and/or spinal cord, facilitating the development of neuropathic pain (NPP) in MS. NPP, the second worst disease-induced symptom suffered by patients with MS, is normally regulated by DRG and/or spinal cord. Objective: To determine gene and protein expression levels of tumor necrosis factor-alpha (TNFα) within DRG and/or spinal cord in an animal model of MS. Methods: Experimental autoimmune encephalomyelitis (EAE) was induced in adolescent female Lewis rats. Animals were sacrificed every 3 days post-disease induction. DRG and spinal cords were harvested for protein and gene expression analysis. Results: We show significant increases in TNFα expression in the DRG and of EAE animals at peak disease stage, as assessed by clinical symptoms. Conclusion: Antigen-induced production of inflammatory cytokines such as TNFα within the DRG identifies a potential novel mechanism for MS-induced NPP.

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The extracellular matrix of the developing cornea: diversity, deposition and function*

Development ◽

10.1242/dev.103.supplement.195 ◽

1988 ◽

Vol 103 (Supplement) ◽

pp. 195-205

Author(s):

J. B. L. Bard ◽

M. K. Bansal ◽

A. S. A. Ross

Keyword(s):

Extracellular Matrix ◽

Chondroitin Sulphate ◽

Corneal Stroma ◽

Experimental System ◽

Collagen I ◽

And Function ◽

20 Nm

This paper examines the role of the extracellular matrix (ECM) in the development of the cornea. After a brief summary of the corneal structure and ECM, we describe evidence suggesting that the differentiation of neural crest (NC) cells into endothelium and fibroblasts is under the control of ocular ECM. We then examine the role of collagen I in stromal morphogenesis by comparing normal corneas with those of homozygous Movl3 mice which do not make collagen I. We report that, in spite of this absence, the cellular morphology of the Movl3 eye is indistinguishable from that of the wild type. In the 16-day mutant stroma, however, the remaining collagens form small amounts of disorganized, thin fibrils rather than orthogonally organized 20 nm-diameter fibrils; a result implying that collagen I plays only a structural role and that its absence is not compensated for. It also suggests that, because these remaining collagens will not form the normal fibrils that they will in vitro, fibrillogenesis in the corneal stroma differs from that elsewhere. The latter part of the paper describes our current work on chick stromal deposition using corneal epithelia isolated with an intact basal lamina that lay down in vitro ∼3μm-thick stromas of organized fibrils similar to that seen in vivo. This experimental system has yielded two unexpected results. First, the amount of collagen and proteoglycans produced by such epithelia is not dependent on whether its substratum is collagenous and we therefore conclude that stromal production by the intact epithelium is more autonomous than hitherto thought. Second, chondroitin sulphate (CS), the predominant proteoglycan, appears to play no role in stromal morphogenesis: epithelia cultured in testicular hyaluronidase, which degrades CS, lay down stromas whose organization and fibrildiameter distribution are indistinguishable from controls. One possible role for CS, however, is as a lubricant which facilitates corneal growth: it could allow fibrils to move over one another without deforming their orthogonal organization. Finally, we have examined the processes of fibrillogenesis in the corneal stroma and conclude that they are different from those elsewhere in the embryo and in vitro, perhaps because there is in the primary stroma an unidentified, highly hydrated ECM macromolecule that embeds the fibrils and that may mediate their morphogenesis.

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Characterization and function of Ca2+-activated K+ channels in arteriolar muscle cells

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1998.274.1.h27 ◽

1998 ◽

Vol 274 (1) ◽

pp. H27-H34 ◽

Cited By ~ 42

Author(s):

William F. Jackson ◽

Kevin L. Blair

Keyword(s):

Single Channel ◽

Muscle Cells ◽

Hill Coefficient ◽

Apparent Lack ◽

Maximal Activation ◽

And Function ◽

Resting Tone

We examined the functional role of large-conductance Ca2+-activated K+(KCa) channels in the hamster cremasteric microcirculation by intravital videomicroscopy and characterized the single-channel properties of these channels in inside-out patches of membrane from enzymatically isolated cremasteric arteriolar muscle cells. In second-order (39 ± 1 μm, n = 8) and third-order (19 ± 2 μm, n = 8) cremasteric arterioles with substantial resting tone, superfusion with the KCa channel antagonists tetraethylammonium (TEA, 1 mM) or iberiotoxin (IBTX, 100 nM) had no significant effect on resting diameters ( P > 0.05). However, TEA potentiated O2-induced arteriolar constriction in vivo, and IBTX enhanced norepinephrine-induced contraction of cremasteric arteriolar muscle cells in vitro. Patch-clamp studies revealed unitary K+-selective and IBTX-sensitive currents with a single-channel conductance of 240 ± 2 pS between −60 and 60 mV ( n = 7 patches) in a symmetrical 140 mM K+ gradient. The free Ca2+ concentration ([Ca2+]) for half-maximal channel activation was 44 ± 3, 20 ± 1, 6 ± 0.4, and 3 ± 0.5 μM at membrane potentials of −60, −30, +30, and +60 mV, respectively ( n = 5), with a Hill coefficient of 1.9 ± 0.2. Channel activity increased e-fold for a 16 ± 1 mV ( n = 6) depolarization. The plot of log[Ca2+] vs. voltage for half-maximal activation ( V ½) was linear ( r 2 = 0.9843, n = 6); the change in V ½ for a 10-fold change in [Ca2+] was 84 ± 5 mV, and the [Ca2+] for half-maximal activation at 0 mV (Ca0; the Ca2+ set point) was 9 μM. Thus, in vivo, KCa channels are silent in cremasteric arterioles at rest but can be recruited during vasoconstriction. We propose that the high Ca0 is responsible for the apparent lack of activity of these channels in resting cremasteric arterioles, and we suggest that this may result from expression of unique KCa channels in the microcirculation.

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PSGL-1 regulates platelet P-selectin-mediated endothelial activation and shedding of P-selectin from activated platelets

Thrombosis and Haemostasis ◽

10.1160/th07-03-0207 ◽

2007 ◽

Vol 98 (10) ◽

pp. 806-812 ◽

Cited By ~ 46

Author(s):

Vandana Dole ◽

Wolfgang Bergmeier ◽

Ian Patten ◽

Junichi Hirahashi ◽

Tanya Mayadas ◽

...

Keyword(s):

Endothelial Activation ◽

Leukocyte Rolling ◽

Wild Type ◽

Platelet Surface ◽

Activated Platelets ◽

And Function ◽

Body Secretion

SummaryWe have previously shown that activated platelets in circulation stimulate release of endothelial Weibel-Palade bodies thus increasing leukocyte rolling in venules. P-selectin on the activated platelets mediates adhesion to leukocytes via PSGL-1 and is rapidly shed into plasma. We were interested in studying the role of PSGL-1 in regulating expression and function of platelet P-selectin. We show here that PSGL-1 is critical for the activation of endothelial cells in venules of mice infused with activated platelets. The interaction of platelet P-selectin with PSGL-1 is also required for P-selectin shedding, as P-selectin was retained significantly longer on the surface of activated platelets infused into PSGL-1-/- compared to wild-type mice. The leukocyte integrin αMβ2 (Mac-1) was not required for P-selectin shedding. In addition to shedding, P-selectin can be downregulated from the platelet surface through internalization and this is the predominant mechanism in the absence of PSGL-1. We demonstrate that leukocyte- neutrophil elastase,known to cleave P-selectin in vitro, is not the major sheddase for P-selectin in vivo. In conclusion, interaction of platelet P-selectin with PSGL-1 is crucial for activation of the endothelium andWeibel-Palade body secretion. The interaction with PSGL-1 also results in rapid shedding of P-selectin thus downregulating the inflammatory potential of the platelet.

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