Capacidade de diferentes ligantes de TLR em modular in vitro o status funcional de células T CD4⁺ de pacientes com doenças do espectro da neuromielite óptica

• Autor(a) principal: Dias, Aleida Soraia Oliveira
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/14384
• topic: Neuromyelitis optica; Toll-like receptor; T helper 17; Neuromielite óptica; Receptores do tipo Toll; T auxiliary 17; Nervo ótico Doenças; Neuromielite Óptica Microbiologia; Células T Receptores; Receptores Toll-Like; CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA::MICROBIOLOGIA APLICADA::MICROBIOLOGIA MEDICA

Neuromyelitis optica spectrum disorders (NMOSD) are rare autoimmune conditions from the central nervous system with a more unfavorable outcome than multiple sclerosis. Despite being considered a disease mediated by autoantibodies, different studies suggest the participation of CD4⁺ T cell subtypes and its severity has been associated with the influence of genetic and environmental factors, such as infections. A recent study published by our group demonstrated a high expansion of Th17 cells positives for TLR2, TLR4 and TLR9 in the peripheral blood of NMOSD patients. Therefore, the objective of this study was to evaluate the ability of different PAMPs in modulating the in vitro functional status of CD4⁺ T cells in those patients and its correlation with clinical parameters. For this, peripheral blood samples were collected from 15 NMOSD patients, in clinical remission, and CD4⁺ T cells were purified by negative selection using magnetic columns. The plasmatic analysis of cytokines and sCD14 were done by the ELISA technique. CD4⁺ T cells were maintained in the presence of medium alone or TLR2 (Pam3C), TLR4 (LPS), TLR5 (FLA) and TLR9 (ODN) agonists. Their ability to modulate the activation of these lymphocytes via TCR was assessed following addition of anti-CD3/anti-CD28. After 3 days, the proliferative response and cytokine production were determined by [3H] TdR uptake and ELISA, respectively. Our results demonstrated that both cell proliferation and IL-6, IL-17 and IL-21 production were higher in the supernatants of NMOSD-derived CD4⁺ T cell cultures in response to LPS, Pam3C and FLA, as compared with the control group. In addition, all these PAMPs amplified the TCR-dependent lymphocytes activation. A positive correlation was observed between the degree of neurological disability of the patients and the secretion of cytokines related to the Th17 profile in cell cultures maintained in the presence of Pam3C and LPS. Plasma sCD14 levels were higher in the patients, in purchased with the control group, and their levels were directly correlated to IL-6 and IL-1β cytokines, measured in vivo, and IL-6, IL-17 and IL-21 levels produced by CD4⁺ T cells in response to LPS. The same correlation was observed between sCD14 and IL-6 and IL-17 released byCD4⁺ T cells from patients in response to Pam3C. Although sCD14 levels were not associated with clinical parameters, the production of IL-6, IL-17 and IL-21 by CD4⁺ T cells in response to Pam3C and LPS, as well as IL-17 and IL-21 following addition of FLA, were positively correlated to the degree of neurological disability. The risk of new relapses was mainly detected in patients whose CD4⁺ T cell cultures responded to LPS releasing high levels of IL-6 and IL-17. In summary, our results suggest that TLR ligands and, especially, TLR2 and TLR4 agonits may exert adverse effects in the course of NMOSD. Although preliminary, these findings help to explain how infections and dysbiosis affect NMOSD severity.