Preservation of lymphocyte functional fitness in perinatally-infected and treated HIV+ pediatric patients displaying sub-optimal viral control

Background Host–pathogen dynamics associated with HIV infection are quite distinct in children versus adults. We interrogated the functional fitness of the lymphocyte responses in two cohorts of perinatally infected HIV+ pediatric subjects with early anti-retroviral therapy (ART) initiation but divergent patterns of virologic control. We hypothesized that sub-optimal viral control would compromise immune functional fitness. Methods The immune responses in the two HIV+ cohorts ( n = 6 in each cohort) were benchmarked against the responses measured in age-range matched, uninfected healthy control subjects ( n = 11) by utilizing tests for normality, and comparison [the Kruskal–Wallis test, and the two-tailed Mann–Whitney U test (where appropriate)]. Lymphocyte responses were examined by intra-cellular cytokine secretion, degranulation assays as well as phosflow. A subset of these data were further queried by an automated clustering algorithm. Finally, we evaluated the humoral immune responses to four childhood vaccines in all three cohorts. Results We demonstrate that contrary to expectations pediatric HIV+ patients with sub-optimal viral control display no significant deficits in immune functional fitness. In fact, the patients that display better virologic control lack functional Gag-specific T cell responses and compared to healthy controls they display signaling deficits and an enrichment of mitogen-stimulated CD3 negative and positive lymphocyte clusters with suppressed cytokine production. Conclusions These results highlight the immune resilience in HIV+ children on ART with sub-optimal viral control. With respect to HIV+ children on ART with better viral control, our data suggest that this cohort might potentially benefit from targeted interventions that might mitigate cell-mediated immune functional quiescence.