RESUMO
Foxp3-expressing CD25+CD4+ regulatory T cells (Tregs) are abundant in tumor tissues. Here, hypothesizing that tumor Tregs would clonally expand after they are activated by tumor-associated antigens to suppress antitumor immune responses, we performed single-cell analysis on tumor Tregs to characterize them by T cell receptor clonotype and gene-expression profiles. We found that multiclonal Tregs present in tumor tissues predominantly expressed the chemokine receptor CCR8. In mice and humans, CCR8+ Tregs constituted 30 to 80% of tumor Tregs in various cancers and less than 10% of Tregs in other tissues, whereas most tumor-infiltrating conventional T cells (Tconvs) were CCR8- CCR8+ tumor Tregs were highly differentiated and functionally stable. Administration of cell-depleting anti-CCR8 monoclonal antibodies (mAbs) indeed selectively eliminated multiclonal tumor Tregs, leading to cure of established tumors in mice. The treatment resulted in the expansion of CD8+ effector Tconvs, including tumor antigen-specific ones, that were more activated and less exhausted than those induced by PD-1 immune checkpoint blockade. Anti-CCR8 mAb treatment also evoked strong secondary immune responses against the same tumor cell line inoculated several months after tumor eradication, indicating that elimination of tumor-reactive multiclonal Tregs was sufficient to induce memory-type tumor-specific effector Tconvs. Despite induction of such potent tumor immunity, anti-CCR8 mAb treatment elicited minimal autoimmunity in mice, contrasting with systemic Treg depletion, which eradicated tumors but induced severe autoimmune disease. Thus, specific removal of clonally expanding Tregs in tumor tissues for a limited period by cell-depleting anti-CCR8 mAb treatment can generate potent tumor immunity with long-lasting memory and without deleterious autoimmunity.
Assuntos
Memória Imunológica , Neoplasias/metabolismo , Receptores CCR8/metabolismo , Animais , Anticorpos Monoclonais , Biomarcadores Tumorais , Diferenciação Celular , Terapia Baseada em Transplante de Células e Tecidos , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Deleção de Genes , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Receptores CCR8/genética , Linfócitos T ReguladoresRESUMO
OBJECTIVE: The relationship between autoimmune diseases and the gut microbiome has been intensively studied, and several autoimmunity-associated bacterial taxa have been identified. However, much less is known about the roles of the gut virome in autoimmune diseases. METHODS: Here, we performed a whole gut virome analysis based on the shotgun sequencing of 476 Japanese which included patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), multiple sclerosis and healthy control subjects. RESULTS: Our case-control comparison of the viral abundance revealed that crAss-like phages, which are one of the main components of a healthy gut virome, significantly decreased in the gut of the patients with autoimmune disease, specifically the patients with RA and SLE. In addition, Podoviridae significantly decreased in the gut of the patients with SLE. To understand how these viruses affected the bacteriome, we performed a quantitative virus-bacterium association analysis and clustered regularly interspaced short palindromic repeat-based virus-bacterium interaction analysis. We identified a symbiosis between Podoviridae and Faecalibacterium. In addition, multiple bacterial targets of crAss-like phages were identified (eg, Ruminococcus spp). CONCLUSION: Our data suggest that the gut virome can affect our body either directly or via bacteria. Our analyses have elucidated a previously missing part of the autoimmunity-associated gut microbiome and presented new candidates that contribute to the development of autoimmune diseases.
Assuntos
Doenças Autoimunes/virologia , Bacteriófagos , Microbioma Gastrointestinal , Viroma , Povo Asiático , Estudos de Casos e Controles , HumanosRESUMO
The recirculation of leukocytes is essential for proper immune responses. However, the molecular mechanisms that regulate the entry of leukocytes into the lymphatics remain unclear. Here we show that plexin-A1, a principal receptor component for class III and class VI semaphorins, was crucially involved in the entry of dendritic cells (DCs) into the lymphatics. Additionally, we show that the semaphorin Sema3A, but not Sema6C or Sema6D, was required for DC transmigration and that Sema3A produced by the lymphatics promoted actomyosin contraction at the trailing edge of migrating DCs. Our findings not only demonstrate that semaphorin signals are involved in DC trafficking but also identify a previously unknown mechanism that induces actomyosin contraction as these cells pass through narrow gaps.
Assuntos
Células Dendríticas/metabolismo , Vasos Linfáticos/metabolismo , Miosina Tipo II/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular/metabolismo , Semaforinas/metabolismo , Actomiosina/metabolismo , Transferência Adotiva , Animais , Ensaios de Migração de Leucócitos , Movimento Celular/imunologia , Células Cultivadas , Células Dendríticas/imunologia , Células Dendríticas/patologia , Técnicas de Introdução de Genes , Imunidade , Vasos Linfáticos/patologia , Camundongos , Camundongos Knockout , Contração Muscular , Miosina Tipo II/imunologia , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/imunologia , Neuropilina-1/genética , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/imunologia , Semaforinas/genética , Semaforinas/imunologia , Transdução de SinaisRESUMO
BACKGROUND: Intractable neuropathic pain is a common symptom of neuromyelitis optica spectrum disorder (NMOSD). However, the underlying mechanism of NMOSD pain remains to be elucidated. In this study, we focused on ATP, which is one of the damage-associated molecular patterns, and also a well-recognized molecule involved in peripheral neuropathic pain. METHODS: We assessed the development of pain symptoms by injecting anti-AQP4 recombinant autoantibodies (rAQP4 IgG) into rat spinal cords. We incubated HEK293 cells expressing AQP4 (HEK-AQP4) and rat astrocytes with rAQP4 IgG and assessed the level of ATP in the supernatant. We performed transcriptome analysis of the spinal cords injected with rAQP4 IgG. Pharmacological inhibition was also applied to investigate the involvement of ATP in the development of neuropathic pain in our rat model. The ATP concentration within the cerebrospinal fluid was examined in patients with NMOSD and other neurological diseases. RESULTS: Development of mechanical allodynia was confirmed in rAQP4 IgG-treated rats. AQP4-Ab-mediated extracellular ATP release from astrocytes was observed in vitro, and pharmacological inhibition of ATP receptor reversed mechanical allodynia in the rAQP4 IgG-treated rats. Furthermore, transcriptome analysis revealed elevation of gene expressions related to several ATP receptors including P2rx4 and IL1B in the spinal cord of rAQP4 IgG-treated rats. In patients, CSF ATP concentration was significantly higher in the acute and remission phase of NMOSD than in multiple sclerosis or other neurological disorders. CONCLUSION: Anti-AQP4 antibody was shown to induce the release of extracellular ATP from astrocytes. The ATP-mediated development of mechanical allodynia was also suggested in rats treated with anti-AQP4 antibody. Our study indicates the pivotal role of ATP in the pain mechanism of NMOSD.
Assuntos
Trifosfato de Adenosina/metabolismo , Aquaporina 4/imunologia , Astrócitos/imunologia , Autoanticorpos/farmacologia , Neuralgia/imunologia , Neuromielite Óptica/imunologia , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Células HEK293 , Humanos , Neuralgia/metabolismo , Neuromielite Óptica/metabolismo , RatosRESUMO
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease; transactivation response DNA-binding protein of 43 kDa (TDP-43) and iron accumulation are supposed to play a crucial role in the pathomechanism of the disease. Here, we report an unusual case of a patient with ALS who presented with speech apraxia as an initial symptom and upper motor neuron deficiencies. In the early clinical stages, single-photon emission computed tomography visualized focal hypoperfusion of the right frontal operculum, and magnetic resonance imaging identified a hypointense area along the frontal lobe on T2-weighted images. Neuropathological examination revealed that neuronophagia of Betz cells, gliosis, appearance of phosphorylated TDP-43 (p-TDP-43)-positive glial and neuronal inclusions, and prominent iron accumulation were frequently visible in the precentral gyrus. TDP-43 pathology and focal iron accumulation were also visible in the frontal operculum, but only a mild neuronal loss and a few p-TDP-43-positive neuronal and glial inclusions were found in the hypoglossal nucleus of the medulla oblongata and anterior horn of the spinal cord. Immunoblot analysis revealed an atypical band pattern for ALS. In our case, abnormal TDP-43 and iron accumulation might possibly have caused neurodegeneration of the frontal operculum, in tandem or independently; it might then have spread into the primary motor area. Our results suggest a causative association between TDP-43 and iron accumulation in the pathomechanisms of ALS presenting with upper motor neuron signs.
Assuntos
Esclerose Lateral Amiotrófica , Apraxias , Córtex Motor , Doenças Neurodegenerativas , Esclerose Lateral Amiotrófica/complicações , Apraxias/diagnóstico por imagem , Humanos , Ferro , Neurônios Motores , FalaRESUMO
BACKGROUND: Sema4A is a regulator of helper T cell (Th) activation and differentiation in the priming phase, which plays an important role in the pathogenesis of experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis (MS). However, the role of Sema4A in the effector phase remains elusive. We aimed to investigate the role of Sema4A at the effector phase in adoptively transferred EAE model. Clinical features and cytokine profiles of MS patients with high Sema4A levels were also examined in detail to clarify the correlation between Sema4A levels and disease activity of patients with MS. METHODS: We adoptively transferred encephalitogenic Th1 or Th17 cells to wild type (WT) or Sema4A-deficient (Sema4A KO) mice and assessed severity of symptoms and cellular infiltration within the central nervous system (CNS). In addition, we analyzed clinical and radiological features (n = 201), levels of serum IFN-γ and IL-17A (n = 86), complete remission ratio by IFN-ß (n = 38) in all of relapsing-remitting multiple sclerosis (RRMS) patients enrolled in this study. RESULTS: Sema4A KO recipient mice receiving Th17-skewed WT myelin oligodendrocyte glycoprotein (MOG)-specific encephalitogenic T cells showed a significant reduction in the clinical score compared to the WT recipient mice. However, Sema4A KO recipient mice showed similar disease activity to the WT recipient mice when transferred with Th1-skewed encephalitogenic T cells. Bone marrow chimeric study indicated that Sema4A expressed on hematopoietic cells, but not the CNS resident cells, are responsible for augmenting Th17-mediated neuroinflammation. Additionally, in contrast to comparable IFN-γ levels, IL-17A is significantly higher in RRMS patients with high Sema4A level than those with low Sema4A patients with high Sema4A levels showed earlier disease onset, more severe disease activity and IFN-ß unresponsiveness than those with low Sema4A levels. CONCLUSIONS: Sema4A is involved not only in the Th cell priming but also in the acceleration of Th17 cell-mediated neuroinflammation in the effector phase, which could contribute to the higher disease activity observed in RRMS patients with high serum Sema4A levels.
Assuntos
Inflamação/imunologia , Esclerose Múltipla Recidivante-Remitente/imunologia , Semaforinas/imunologia , Células Th17/imunologia , Animais , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/patologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Semaforinas/sangueRESUMO
BACKGROUND: The spectrum of classical and non-classical HLA genes related to the risk of multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) in the Japanese population has not been studied in detail. We conducted a case-control analysis of classical and non-classical HLA genes. METHODS: We used next-generation sequencing (NGS)-based HLA genotyping methods for mapping risk for 45 MS patients, 31 NMOSD patients, and 429 healthy controls. We evaluated the association of the HLA variants with the risk of MS and NMOSD using logistic regression analysis and Fisher's exact test. RESULTS: We confirmed that HLA-DRB1*15:01 showed the strongest association with MS (P = 2.1 × 10-5; odds ratio [OR] = 3.44, 95% confidence interval [95% CI] = 1.95-6.07). Stepwise conditional analysis identified HLA-DRB1*04:05, HLA-B*39:01, and HLA-B*15:01 as being associated with independent MS susceptibility (PConditional < 8.3 × 10-4). With respect to amino acid polymorphisms in HLA genes, we found that phenylalanine at HLA-DQß1 position 9 had the strongest effect on MS susceptibility (P = 3.7 × 10-8, OR = 3.48, 95% CI = 2.23-5.43). MS risk at HLA-DQß1 Phe9 was independent of HLA-DRB1*15:01 (PConditional = 1.5 × 10-5, OR = 2.91, 95% CI = 1.79-4.72), while HLA-DRB1*15:01 was just significant when conditioned on HLA-DQß1 Phe9 (PConditional = 0.037). Regarding a case-control analysis for NMOSD, HLA-DQA1*05:03 had a significant association with NMOSD (P = 1.5 × 10-4, OR = 6.96, 95% CI = 2.55-19.0). CONCLUSIONS: We identified HLA variants associated with the risk of MS and NMOSD. Our study contributes to the understanding of the genetic architecture of MS and NMOSD in the Japanese population.
Assuntos
Predisposição Genética para Doença , Antígenos HLA/genética , Esclerose Múltipla/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos de Casos e Controles , Feminino , Estudos de Associação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/imunologia , Adulto JovemRESUMO
Mechanistic target of rapamycin complex (mTORC)1 integrates intracellular sufficiency of nutrients and regulates various cellular functions. Previous studies using mice with conditional knockout of mTORC1 component proteins (i.e., mTOR, Raptor, and Rheb) gave conflicting results on the roles of mTORC1 in CD4+ T cells. Lamtor1 is the protein that is required for amino acid sensing and activation of mTORC1; however, the roles of Lamtor1 in T cells have not been investigated. In this article, we show that Lamtor1-deficient CD4+ T cells exhibited marked reductions in proliferation, IL-2 production, mTORC1 activity, and expression of purine- and lipid-synthesis genes. Polarization of Th17 cells, but not Th1 and Th2 cells, diminished following the loss of Lamtor1. Accordingly, CD4-Cre-driven Lamtor1-knockout mice exhibited reduced numbers of CD4+ and CD8+ T cells at rest, and they were completely resistant to experimental autoimmune encephalomyelitis. In contrast, genetic ablation of Lamtor1 in Foxp3+ T cells resulted in severe autoimmunity and premature death. Lamtor1-deficient regulatory T cells survived ex vivo as long as wild-type regulatory T cells; however, they exhibited a marked loss of suppressive function and expression of signature molecules, such as CTLA-4. These results indicate that Lamtor1 plays essential roles in CD4+ T cells. Our data suggest that Lamtor1 should be considered a novel therapeutic target in immune systems.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Encefalomielite Autoimune Experimental/imunologia , Esclerose Múltipla/imunologia , Complexos Multiproteicos/metabolismo , Subpopulações de Linfócitos T/fisiologia , Linfócitos T Reguladores/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Células Th17/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Diferenciação Celular/genética , Proliferação de Células , Células Cultivadas , Humanos , Interleucina-2/metabolismo , Metabolismo dos Lipídeos , Ativação Linfocitária , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system. Although complement-dependent astrocyte damage mediated by anti-aquaporin 4 autoantibody (AQP4-Ab) is well acknowledged to be the core of NMOSD pathogenesis, additional inflammatory cascades may contribute to the establishment of lesion formation. Thus, in this study, we investigated the possible pathogenic role of immune-reactive mitochondrial DNA (mtDNA) in cerebrospinal fluid (CSF) of NMOSD patients. METHODS: Using quantitative polymerase chain reaction, we measured extracellular mtDNA levels in CSF of NMOSD patients positive for AQP4-Ab. Patients with multiple sclerosis or other neurological diseases were examined as controls. Pre- and post-treatment extracellular mtDNA levels were also compared in the NMOSD group. Extracellular mtDNA release from human astrocytes was analyzed in vitro utilizing NMOSD sera, and interleukin (IL)-1ß production was measured in supernatants of mixed glial cells stimulated with DNA fraction of CSF derived from NMOSD patients. Furthermore, specific innate immune pathways mediating the IL-1ß production by mtDNA were investigated in peripheral blood mononuclear cells with selective inhibitors of Toll-like receptor 9 (TLR9) and NOD-like receptor protein 3 (NLRP3) inflammasomes. RESULTS: Extracellular mtDNA level was specifically elevated in acute phase of NMOSD CSF. In vitro studies provided the evidence that mtDNA is released from human astrocytes by NMOSD sera. In addition, DNA fraction isolated from NMOSD CSF promoted secretion of IL-1ß from mixed glial cells. Selective inhibition of TLR9 and NLRP3 inflammasomes revealed that mtDNA-mediated IL-1ß production depends on specific innate immune pathways. CONCLUSION: Extracellular mtDNA is specifically elevated in the CSF of patients with acute phase NMOSD, and mtDNA released by AQP4-Ab-mediated cellular damage elicits the innate immune cascades via TLR9 and NLRP3 inflammasomes pathways. Our study highlights mtDNA-mediated innate immune pathways as a novel therapeutic target for future treatment of NMOSD patients.
Assuntos
DNA Mitocondrial/sangue , DNA Mitocondrial/líquido cefalorraquidiano , Neuromielite Óptica/sangue , Neuromielite Óptica/líquido cefalorraquidiano , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Aquaporina 4/sangue , Aquaporina 4/líquido cefalorraquidiano , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Feminino , Células HEK293 , Humanos , Imunidade Inata/fisiologia , Interleucina-1beta/sangue , Interleucina-1beta/líquido cefalorraquidiano , Leucócitos Mononucleares/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Neuromielite Óptica/diagnóstico , Adulto JovemAssuntos
Vacinas contra COVID-19 , COVID-19 , Humanos , SARS-CoV-2 , COVID-19/prevenção & controle , Vacinação , Anticorpos AntiviraisRESUMO
Commissural axon guidance requires complex modulations of growth cone sensitivity to midline-derived cues, but underlying mechanisms in vertebrates remain largely unknown. By using combinations of ex vivo and in vivo approaches, we uncovered a molecular pathway controlling the gain of response to a midline repellent, Semaphorin3B (Sema3B). First, we provide evidence that Semaphorin3B/Plexin-A1 signaling participates in the guidance of commissural projections at the vertebrate ventral midline. Second, we show that, at the precrossing stage, commissural neurons synthesize the Neuropilin-2 and Plexin-A1 Semaphorin3B receptor subunits, but Plexin-A1 expression is prevented by a calpain1-mediated processing, resulting in silencing commissural responsiveness. Third, we report that, during floor plate (FP) in-growth, calpain1 activity is suppressed by local signals, allowing Plexin-A1 accumulation in the growth cone and sensitization to Sema3B. Finally, we show that the FP cue NrCAM mediates the switch of Plexin-A1 processing underlying growth cone sensitization to Sema3B. This reveals pathway-dependent modulation of guidance receptor processing as a novel mechanism for regulating guidance decisions at intermediate targets.
Assuntos
Axônios/fisiologia , Neurônios/citologia , Transdução de Sinais , Animais , Axônios/metabolismo , Calpaína/metabolismo , Moléculas de Adesão Celular/metabolismo , Embrião de Galinha , Embrião de Mamíferos , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Neuropilina-2/metabolismo , Semaforinas/metabolismoRESUMO
Mammalian target of rapamycin (mTOR) plays crucial roles in activation and differentiation of diverse types of immune cells. Although several lines of evidence have demonstrated the importance of mTOR-mediated signals in CD4(+) T cell responses, the involvement of mTOR in CD8(+) T cell responses is not fully understood. In this study, we show that a class IV semaphorin, SEMA4A, regulates CD8(+) T cell activation and differentiation through activation of mTOR complex (mTORC) 1. SEMA4A(-/-) CD8(+) T cells exhibited impairments in production of IFN-γ and TNF-α and induction of the effector molecules granzyme B, perforin, and FAS-L. Upon infection with OVA-expressing Listeria monocytogenes, pathogen-specific effector CD8(+) T cell responses were significantly impaired in SEMA4A(-/-) mice. Furthermore, SEMA4A(-/-) CD8(+) T cells exhibited reduced mTORC1 activity and elevated mTORC2 activity, suggesting that SEMA4A is required for optimal activation of mTORC1 in CD8(+) T cells. IFN-γ production and mTORC1 activity in SEMA4A(-/-) CD8(+) T cells were restored by administration of recombinant Sema4A protein. In addition, we show that plexin B2 is a functional receptor of SEMA4A in CD8(+) T cells. Collectively, these results not only demonstrate the role of SEMA4A in CD8(+) T cells, but also reveal a novel link between a semaphorin and mTOR signaling.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Ativação Linfocitária/imunologia , Complexos Multiproteicos/imunologia , Proteínas do Tecido Nervoso/fisiologia , Semaforinas/fisiologia , Serina-Treonina Quinases TOR/imunologia , Animais , Linfócitos T CD8-Positivos/citologia , Diferenciação Celular/imunologia , Proliferação de Células , Proteína Ligante Fas/biossíntese , Granzimas/biossíntese , Interferon gama/biossíntese , Listeria monocytogenes/imunologia , Listeriose/imunologia , Alvo Mecanístico do Complexo 1 de Rapamicina , Alvo Mecanístico do Complexo 2 de Rapamicina , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Complexos Multiproteicos/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas Citotóxicas Formadoras de Poros/biossíntese , Ligação Proteica/imunologia , Interferência de RNA , RNA Interferente Pequeno , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Semaforinas/genética , Transdução de Sinais/imunologia , Serina-Treonina Quinases TOR/metabolismo , Fator de Necrose Tumoral alfa/biossínteseRESUMO
BACKGROUND: Accumulating evidence has shown that the inflammatory process participates in the pathogenesis of amyotrophic lateral sclerosis (ALS), suggesting a therapeutic potential of anti-inflammatory agents. Janus kinase 2 (JAK2), one of the key molecules in inflammation, transduces signals downstream of various inflammatory cytokines, and some Janus kinase inhibitors have already been clinically applied to the treatment of inflammatory diseases. However, the efficacy of JAK2 inhibitors in treatment of ALS remains to be demonstrated. In this study, we examined the role of JAK2 in ALS by administering a selective JAK2 inhibitor, R723, to an animal model of ALS (mSOD1G93A mice). FINDINGS: Orally administered R723 had sufficient access to spinal cord tissue of mSOD1G93A mice and significantly reduced the number of Ly6c positive blood monocytes, as well as the expression levels of IFN-γ and nitric oxide synthase 2, inducible (iNOS) in the spinal cord tissue. R723 treatment did not alter the expression levels of Il-1ß, Il-6, TNF, and NADPH oxidase 2 (NOX2), and suppressed the expression of Retnla, which is one of the markers of neuroprotective M2 microglia. As a result, R723 did not alter disease progression or survival of mSOD1G93A mice. CONCLUSIONS: JAK2 inhibitor was not effective against ALS symptoms in mSOD1G93A mice, irrespective of suppression in several inflammatory molecules. Simultaneous suppression of anti-inflammatory microglia with a failure to inhibit critical other inflammatory molecules might explain this result.
Assuntos
Esclerose Lateral Amiotrófica/patologia , Inibidores Enzimáticos/farmacologia , Janus Quinase 2/antagonistas & inibidores , Microglia/efeitos dos fármacos , Degeneração Neural/prevenção & controle , Animais , Modelos Animais de Doenças , Citometria de Fluxo , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Degeneração Neural/enzimologia , Degeneração Neural/imunologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/imunologia , Medula Espinal/patologiaRESUMO
The intestinal immune system is constantly challenged by commensal bacteria; therefore, it must maintain quiescence via several regulatory mechanisms. Although intestinal macrophages (Ms) have been implicated in repression of excessive inflammation, it remains unclear how their functions are regulated during inflammation. In this study, we report that semaphorin 7A (Sema7A), a GPI-anchored semaphorin expressed in intestinal epithelial cells (IECs), induces IL-10 production by intestinal MÏs to regulate intestinal inflammation. Sema7A-deficient mice showed severe signs of dextran sodium sulfate-induced colitis due to reduced intestinal IL-10 levels. We further identified CX3CR1(+)MHC class II(int)F4/80(hi)CD11b(hi) MÏs as the main producers of IL-10 via αvß1 integrin in response to Sema7A. Notably, Sema7A was predominantly expressed on the basolateral side of IECs, and its expression pattern was responsible for protective effects against dextran sodium sulfate-induced colitis and IL-10 production by MÏs during interactions between IECs and MÏs. Furthermore, we determined that the administration of recombinant Sema7A proteins ameliorated the severity of colitis, and these effects were diminished by IL-10-blocking Abs. Therefore, our findings not only indicate that Sema7A plays crucial roles in suppressing intestinal inflammation through αvß1 integrin, but also provide a novel mode of IL-10 induction via interactions between IECs and MÏs.
Assuntos
Antígenos CD/fisiologia , Colite/patologia , Receptores de Vitronectina/fisiologia , Semaforinas/fisiologia , Animais , Comunicação Celular , Colite/etiologia , Células Epiteliais/metabolismo , Interleucina-10/biossíntese , Interleucina-10/genética , Intestinos , Macrófagos , CamundongosRESUMO
Multiple sclerosis (MS) is a demyelinating autoimmune disease of the CNS and a leading cause of lasting neurologic disabilities in young adults. Although the precise mechanism remains incompletely understood, Ag presentation and subsequent myelin-reactive CD4(+) T cell activation/differentiation are essential for the pathogenesis of MS. Although semaphorins were initially identified as axon guidance cues during neural development, several semaphorins are crucially involved in various phases of immune responses. Sema4A is one of the membrane-type class IV semaphorins, which we originally identified from the cDNA library of dendritic cell (DC). Sema4A plays critical roles in T cell activation and Th1 differentiation during the course of experimental autoimmune encephalomyelitis, an animal model of MS; however, its pathological involvement in human MS has not been determined. In this study, we report that Sema4A is increased in the sera of patients with MS. The expression of Sema4A is increased on DCs in MS patients and shed from these cells in a metalloproteinase-dependent manner. DC-derived Sema4A is not only critical for Th1 but also for Th17 cell differentiation, and MS patients with high Sema4A levels exhibit Th17 skewing. Furthermore, patients with high Sema4A levels have more severe disabilities and are unresponsive to IFN-ß treatment. Taken together, our results suggest that Sema4A is involved in the pathogenesis of MS by promoting Th17 skewing.
Assuntos
Diferenciação Celular/imunologia , Interferon beta/uso terapêutico , Esclerose Múltipla/imunologia , Esclerose Múltipla/terapia , Semaforinas/biossíntese , Células Th17/imunologia , Regulação para Cima/imunologia , Sequência de Aminoácidos , Animais , Diferenciação Celular/genética , Células Cultivadas , Técnicas de Cocultura , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Dendríticas/patologia , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/patologia , Feminino , Humanos , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Masculino , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Esclerose Múltipla/patologia , Ratos , Semaforinas/sangue , Semaforinas/deficiência , Semaforinas/metabolismo , Células Th17/metabolismo , Células Th17/patologia , Regulação para Cima/genéticaRESUMO
CD4+ T cells are key mediators of various autoimmune diseases; however, their role in disease progression remains unclear due to cellular heterogeneity. Here, we evaluated CD4+ T cell subpopulations using decomposition-based transcriptome characterization and canonical clustering strategies. This approach identified 12 independent gene programs governing whole CD4+ T cell heterogeneity, which can explain the ambiguity of canonical clustering. In addition, we performed a meta-analysis using public single-cell datasets of over 1.8 million peripheral CD4+ T cells from 953 individuals by projecting cells onto the reference and cataloging cell frequency and qualitative alterations of the populations in 20 diseases. The analyses revealed that the 12 transcriptional programs were useful in characterizing each autoimmune disease and predicting its clinical status. Moreover, genetic variants associated with autoimmune diseases showed disease-specific enrichment within the 12 gene programs. The results collectively provide a landscape of single-cell transcriptomes of CD4+ T cell subpopulations involved in autoimmune disease.
Assuntos
Doenças Autoimunes , Transcriptoma , Humanos , Transcriptoma/genética , Linfócitos T , Doenças Autoimunes/genética , Linfócitos T CD4-PositivosRESUMO
Myasthenia gravis (MG) is etiologically associated with thymus abnormalities, but its pathology in the thymus remains unclear. In this study, we attempt to narrow down the features associated with MG using spatial transcriptome analysis of thymoma and thymic hyperplasia samples. We find that the majority of thymomas are constituted by the cortical region. However, the small medullary region is enlarged in seropositive thymomas and contains polygenic enrichment and MG-specific germinal center structures. Neuromuscular medullary thymic epithelial cells, previously identified as MG-specific autoantigen-producing cells, are enriched in the cortico-medullary junction. The medulla is characterized by a specific chemokine pattern and immune cell composition, including migratory dendritic cells and effector regulatory T cells. Similar germinal center structures and immune microenvironments are also observed in the thymic hyperplasia medulla. This study shows that the medulla and junction areas are linked to MG pathology and provides insights into future MG research.
RESUMO
OBJECTIVES: This study aimed to evaluate whether switching disease-modifying therapies (DMTs) from sphingosine-1 phosphate (S1P) receptor modulators to either natalizumab (NTZ) or dimethyl fumarate (DMF) could restore the effectiveness of SARS-CoV-2 mRNA vaccination in patients with multiple sclerosis (MS). METHODS: This study included 9 controls and 33 patients with MS: 7 patients treated with DMF, 7 patients treated with NTZ, 9 patients treated with S1P receptor modulators, and 10 patients who had switched DMTs from S1P receptor modulators to DMF or NTZ by the second vaccine dose. The patients who had switched DMTs were classified into two groups, based on whether their lymphocyte counts were above or below 1000/µL at the time of vaccination. In addition, relapses within 6 months after switching DMTs were also evaluated in these patients. Six months after the second dose of the vaccination, anti-SARS-CoV-2 spike antibodies were evaluated in all participants, and spike specific CD4+ T cells were also assessed in patients who had switched DMTs from S1P receptor modulators. RESULTS: Patients treated with S1P receptor modulators had lower levels of anti-SARS-CoV-2 spike antibodies than the controls and patients treated with DMF and NTZ. On the other hand, in patients who had switched DMTs from S1P receptor modulators, a recovery of lymphocyte counts above 1000/µL resulted in restored humoral and cellular immune responses to the vaccination. There were no neurological relapses in patients who had switched DMTs from S1P receptor modulators to NTZ. CONCLUSION: SARS-CoV-2 mRNA vaccination is expected to be effective in patients whose lymphocyte counts have recovered due to switching DMTs from S1P receptor modulators. Switching DMTs from S1P receptor modulators to NTZ before vaccination may be beneficial in achieving efficacy for SARS-CoV-2 mRNA vaccination, with a reduced risk of relapse.
Assuntos
COVID-19 , Fumarato de Dimetilo , Esclerose Múltipla , Natalizumab , SARS-CoV-2 , Humanos , Feminino , Fumarato de Dimetilo/uso terapêutico , Masculino , Adulto , Natalizumab/uso terapêutico , Pessoa de Meia-Idade , Esclerose Múltipla/imunologia , Esclerose Múltipla/tratamento farmacológico , COVID-19/prevenção & controle , COVID-19/imunologia , SARS-CoV-2/imunologia , Moduladores do Receptor de Esfingosina 1 Fosfato/uso terapêutico , Moduladores do Receptor de Esfingosina 1 Fosfato/farmacologia , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/uso terapêutico , Imunossupressores/uso terapêutico , Vacinação/métodos , Substituição de Medicamentos , Anticorpos Antivirais/sangueRESUMO
BACKGROUND: The previous Japanese clinical practice guidelines for multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) were published in 2017. Recently, for the first time in 6 years, the MS and NMOSD guideline development committee revised the Japanese guidelines for MS, NMOSD, and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). METHODS: The committee utilized the Grading of Recommendations Assessment, Development, and Evaluation system based on the "Minds Handbook for Clinical Practice Guideline Development 2020 Ver. 3.0â³ with a focus on clinical questions (CQs). The committee also discussed clinical issues other than CQs, categorizing them as a question-and-answer (Q&A) section, including "issues on which experts' opinions agree to a certain extent" and "issues that are important but not included in the CQ". RESULTS: The committee identified 3, 1, and 1 key CQs related to MS, NMOSD, and MOGAD, respectively, and presented recommendations. A Q&A session regarding disease-modifying therapies and relapse prevention therapies for MS, NMOSD, and MOGAD was conducted. The revised guidelines were published in September 2023. CONCLUSIONS: The Japanese guidelines for clinical practice on MS, NMOSD, and MOGAD were updated. Treatment strategies for MS, NMOSD, and MOGAD are changing, and these updated guidelines may assist with treatment decisions for these diseases in clinical practice.