ABSTRACT
BACKGROUND: We investigated immune activation, exhaustion markers and cytokine expression upon stimulation in adolescents with vertical HIV infection. METHODS: Thirty adolescents receiving antiretroviral therapy (ART) for vertical HIV infection, including 12 with detectable viral load (HIV/DET), 18 with undetectable viral load (HIV/UND) and 30 control adolescents without HIV infection (CONTROL), were evaluated for immune activation and programmed cell death protein-1 expression by flow cytometry, and 21 cytokines by Luminex Multiple Analyte Profiling technology after in vitro peripheral blood phytohemagglutinin stimulation. RESULTS: Lower CD4 T cells and higher T cell activation and exhaustion markers were noted on CD4 T and on CD8 T cells and memory subsets from HIV/DET group, who also produced lower in vitro IFN-gamma, IL-10, IL-13, IL-17A, IL-5 and IL-6 than HIV/UND group. HIV/UND were comparable with CONTROL group in respect to CD4 T cell counts and T cell activation and exhaustion markers, but with higher in vitro production of ITAC (a chemokine with leukocyte recruitment function), IL-4 and IL-23. An inverse correlation between cytokine production and programmed cell death protein-1 expression on CD4 T and CD8 T subsets was detected. CONCLUSIONS: Persistent viremia despite ART leads to T cell activation and immune exhaustion with low cytokine production, whereas viral suppression by ART leads to parameters similar to CONTROL, although a different cytokine profile is observed, indicating residual HIV impact despite absence of detectable viremia.
