Decay kinetics of HIV-1 specifict cell responses in vertically HIV-1 exposed seronegative infants

Abstract

Objective: The majority of infants born, in developed countries, to HIV-1 positive women are exposed to the HIV-1 virus inutero or peri/post-partum, but are born uninfected.We, and others, have previously shown HIV-1 specificT cell responses in HIV-1 exposed seronegative (HESN) neonates/infants. Our objective in this study was to examine the rate of decay in their HIV-1 specificT cell response over time from birth. Design: Cross-sectional and longitudinal studies of HIV-1 specificT cell responses in HESN infants were performed. Methods: Peripheral blood mononuclear cells (PBMC) were isolated from 18 HIV-1 DNA PCR negative infants born to HIV-1 infected mothers receiving care at the Jacobi Medical Center, Bronx, NY USA. PBMC were examined forT cell responses to HIV-1 antigens by interferon-gamma (IFN-γ) ELISPOT. Results: PBMC from 15 HESN neonates/infants were analyzed. We observed a decay of HIV-1 specificT cell responses from birth at a rate of -0.599 spot forming unit/106 cells per day, with a median half-life decay rate of 21.38 weeks (13.39-115.8). Conclusion: Our results support the dynamic nature of T cell immunity in the context of a developing immune system. The disparate rate of decay with studies of adults placed on antiretroviral drugs suggests that antigen specificT cell responses are driven by the natural rate of decay of theT cell sub-populations themselves. © 2012 Holditch.