Avaliação de diferentes subtipos de linfócitos T produtores de IL-17 e de células T reguladoras em pacientes cronicamente infectados pelo vírus da hepatite C

• Autor(a) principal: Cachem, Fabio Christiane de Oliveira Felix
• Data de Publicação: 2018
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/14344
• topic: Hepatitis C virus; T cells; Interferon-γ; Interleukin-21; Interleukin-17; Core HCV protein; Hepatite C; Interferon gama; Vírus da hepatite C; Células T; Interferon-γ; Interleucina-21; Interleucina-17; Proteína core do HCV; Linfócitos T; Interleucina 17; CNPQ::CIENCIAS BIOLOGICAS::IMUNOLOGIA

Chronic hepatitis C (CHC) is often associated with liver fibrosis, which can lead to cirrhosis and hepatocellular carcinoma. Many studies have suggested that immunological activity in response to HCV antigens is strongly related to liver fibrosis. The role of different IL-17 secreting CD4+ (Th17) and CD8+ (Tc17) T cells in CHCis not fully understood. In our study, elevated plasma levels of IL-1β, IL-6 and IL-17 were positively correlated with fibrosis and alanine transaminase (ALT) rates in patients with CHC. In addition, these cytokines, secreted by peripheral blood mononuclear cell (PBMC) cultures in response to core antigen from virus, were also correlated to advanced liver injury. While the percentage of IL-17 producing Th17/Tc17 cells in association with IFN-γ or IL-21 was higher in patients with lower liver damage, accumulation of single IL-17-producing T lymphocytes was correlated with liver fibrosis. Interestingly, core protein favored the expansion of Th17/Tc17 cell subtypes related to disease progression, identified by production of IL-17 alone or IL-17 in association with IL-6. Further, although the percentage of Tregs FoxP3+CD25+CD4+) was higher in CHC patients with more advanced disease, the proportions of both TregsCD39+or Treg17 (IL-17+ IL-10 +) subsets were significantly lower in these individuals. Addition of HCV core protein to the PBMC cultures elevated the percentage of CD39-Tregs cells. In addition, the percentage of exhausted (PD-1+ CD28+) and senescent (CD28-CD57+) T cells were not only higher in patients with advanced hepatic fibrosis, but also their proportion were elevated by core antigen. Finally, we believe that the presence of a persistent and pro-fibrotic inflammatory state is facilitated by an elevated bacterial translocation, since, in the present study, plasma levels of sCD14 were not only higher in patients with worse prognosis, but their concentrations were directly correlated with the systemic levels of IL-1β, IL-6 and IL-17, as well as the percentage of Th17 / Tc17 cells negatives for IL-21 and IFN-γ. In summary, although preliminary, our results suggest that the expansion of different Th17 / Tc17 and Tregs cell subsets may influence the evolution of liver disease in patients with CHC, and reveals that the core antigen may exert adverse effects by amplifying the imbalance among these different subtypes of these T cells. In addition, inflammatory events favoring the expansion of different Th17/Tc17 cells implicated in hepatic fibrosis may be favored by greater intestinal microbial translocation.