Subpopulações e ativação de linfócitos T CD4+ e T CD8+ em crianças e adolescentes HIV positivos vacinados contra Neisseria meningitidis C

Abstract

Neisseria meningitidis serogrupo C (MenC) has been causing outbreaks in Brazil, since 2005. MenC conjugated vaccines has been available since 1999 in developed countries and more recently in Brazil. They are effective in immunologically normal patient, but little is known about impact in HIV+ patients. The main purpose was investigate whether there are correlations between memory CD4 T cell response and specific antibodies response for MenC, as well as, to know memory CD8 T cell populations in HIV-infected children and teens, responders or not to MenC conjugated vaccine. Blood sample from 36 HIV patients were collected, before and after immunization, for laboratory analysis. Serum and collected cells were frozen and sent to our laboratory for cellular and humoral response analysis. We used bactericidal tests to evaluate the humoral response and share the population, in positive or negative seroconversion. The flow cytometry was used to identify the six CD4 T cells and CD8 T cells subpopulations and evaluate profile activation. We didn´t find changes in the distribution profile, before and after vaccination. The LT CD4 Int subpopulation positively correlated with antibodies titers. Generally, the activation was increased in responders, giving relevance to this cell. Similarities were observed between CD4 T cells and CD8 T cells subpopulations. In conclusion, this study revealed important associations between the bactericidal antibodies response after vaccination, the distribution profile of CD4 T cells and CD8 T cells subsets and their activation status.