RESUMO
Connective tissue growth factor (CTGF/CCN2) is a matricellular protein susceptible to proteolytic degradation. CCN2 levels have been suggested as a potential risk biomarker in several chronic diseases. In body fluids, CCN2 full-length and its degradation fragments can be found; however, their in vivo effects are far from being elucidated. CCN2 was described as a profibrotic mediator, but this concept is changing to a proinflammatory cytokine. In vitro, CCN2 full-length and its C-terminal module IV (CCN2(IV)) exert proinflammatory properties. Emerging evidence suggest that Th17 cells, and its effector cytokine IL-17A, participate in chronic inflammatory diseases. Our aim was to explore whether CCN2(IV) could regulate the Th17 response. In vitro, stimulation of human naive CD4+ T lymphocytes with CCN2(IV) resulted in differentiation to Th17 phenotype. The in vivo effects of CCN2(IV) were studied in C57BL/6 mice. Intraperitoneal administration of recombinant CCN2(IV) did not change serum IL-17A levels, but caused an activation of the Th17 response in the kidney, characterized by interstitial infiltration of Th17 (IL17A+/CD4+) cells and upregulation of proinflammatory mediators. In CCN2(IV)-injected mice, elevated renal levels of Th17-related factors (IL-17A, IL-6, STAT3 and RORγt) were found, whereas Th1/Th2 cytokines or Treg-related factors (TGF-ß and Foxp-3) were not modified. Treatment with an anti-IL-17A neutralizing antibody diminished CCN2(IV)-induced renal inflammation. Our findings unveil that the C-terminal module of CCN2 induces the Th17 differentiation of human Th17 cells and causes a renal Th17 inflammatory response. Furthermore, these data bear out that IL-17A targeting is a promising tool for chronic inflammatory diseases, including renal pathologies.
Assuntos
Fator de Crescimento do Tecido Conjuntivo/metabolismo , Interleucina-17/sangue , Rim/imunologia , Células Th17/fisiologia , Animais , Fator de Crescimento do Tecido Conjuntivo/administração & dosagem , Humanos , Rim/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fatores de Transcrição/metabolismo , Regulação para CimaRESUMO
The small guanine nucleotide binding proteins of the Ras family, including in mammals the highly homologous H-ras, N-ras, and K-ras isoforms, are rapidly activated on ligation of the T-cell antigen receptor (TCR), but whether each isoform plays specific roles in T cells is largely unknown. Here, we show, with the use of mice specifically lacking H-ras or N-ras, that these isoforms are dispensable for thymocyte development and mature T-cell activation. By contrast, CD4⺠T cells from Ras-deficient mice exhibited markedly decreased production of the Th1 signature cytokine IFN-γ early after TCR stimulation, concomitantly with impaired induction of the Th1-specific transcription factor T-bet. Accordingly, Ras-deficient mice failed to mount a protective Th1 response in vivo against the intracellular parasite Leishmania major, although they could be rendered resistant to infection if a Th1-biased milieu was provided during parasite challenge. Collectively, our data indicate that the TCR recruits distinct Ras isoforms for signal transduction in developing and mature T cells, thus providing a mechanism for differential signaling from the same surface receptor. Furthermore, we demonstrate for the first time that H-ras and N-ras act as critical controllers of Th1 responses, mostly by transmitting TCR signals for Th1 priming of CD4⺠T cells.
Assuntos
Diferenciação Celular/genética , Genes ras/imunologia , Ativação Linfocitária/genética , Transdução de Sinais/imunologia , Células Th1/imunologia , Animais , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular/imunologia , Separação Celular , Citometria de Fluxo , Immunoblotting , Leishmaniose/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/genética , Células Th1/citologiaRESUMO
Natalizumab is a widely accepted drug for the relapsing-remitting subtype of multiple sclerosis (RRMS). The present longitudinal exploratory study in RRMS patients analyzes the effects of natalizumab treatment on the levels of pro-inflammatory and anti-inflammatory cytokine protein levels and also the frequency and suppressor function of regulatory T cells. Flow cytometry was used to determine cytokines and regulatory T cell frequency while regulatory T cell suppressor function was assayed in vitro at different time-points after starting with natalizumab. Results showed serum levels of pro-inflammatory interferon gamma and interleukin (IL)-12p70, as well as anti-inflammatory IL-4 and IL-10, were elevated just a few hours or days after first IV infusion of natalizumab. Interestingly, other cytokines like IL-5 or IL-13 were also elevated while pro-inflammatory IL-17, IL-2, and IL-1ß increased only after a long-term treatment, suggesting different immune mechanisms. In contrast, we did not observe any effect of natalizumab treatment on regulatory T cell frequency or activity. In conclusion, these results suggest natalizumab has other immunological effects beyond VLA-4 interaction and inhibition of CNS extravasation, the relevance of which is as yet unknown and warrants further investigation.
Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Citocinas/sangue , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Linfócitos T Reguladores/imunologia , Adulto , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/farmacologia , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Integrina alfa4beta1/imunologia , Estudos Longitudinais , Masculino , Esclerose Múltipla Recidivante-Remitente/imunologia , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Natalizumab , Recidiva , Linfócitos T Reguladores/metabolismoRESUMO
The therapeutic potential of natural anti-T-cell receptor (TCR) antibodies is largely unknown. We investigated whether passive administration of C1-19, a novel natural anti-TCRVß8 monoclonal antibody, could interfere with the development of EAE. Treatment with C1-19 prevented myelin basic protein (MBP)-induced EAE in Vß8-sufficient B10.PL but not in Vß8-deficient SJL mice. Furthermore, C1-19 reduced disease severity when administrated shortly after disease onset. These protective effects of C1-19 correlated with a Th2 bias of the cytokine response, in the absence of T-cell deletion or anergy. Together, these findings indicate that natural anti-TCR antibodies could function as therapeutic tools in autoimmune inflammatory diseases.