Enhanced T-Cell Maturation, Differentiation and Function in HIV-1-Infected Individuals after Growth Hormone and Highly Active Antiretroviral Therapy

Abstract

Strong virus-specific helper and cytotoxic T-cell responses correlate with non-progression during HIV-1 infection. Administration of antiretroviral therapy (ART) during the chronic phases of HIV-1 infection fails to restore these responses in most patients. We assessed the changes in immune function of 12 HIV-1-positive individuals treated with ART for over 4 years, who received 4 mg/day of recombinant human growth hormone (rhGH) for 12 weeks and were then randomized into groups receiving either placebo, twice weekly or alternate day dosing of rhGH. Peripheral blood was drawn for phenotypic analysis and functional assays at time points 0, 12 and 24 weeks. At week 12, we observed significant increases in naive CD4 T cells (P<0.01) and effector CD8 T cells based on CD45RA and CCR7 expression (P<0.02). In addition, we observed a rise in HIV-1 antigen-specific CD4 (P<0.005) and CD8 (P<0.05) T-cell responses. Twelve weeks post-randomization into placebo, alternate day or twice weekly dosing (24 weeks post-baseline), the phenotype and function of the virus-specific effector CD8 T cells seen at week 12 was maintained in most patients regardless of randomization arm and despite the disappearance of HIV-1-specific CD4 T-cell responses. Concomitant administration of rhGH at 4 mg/day with highly active ART appears to partially reverse some of the defects exerted on the immune system by HIV-1. This combination may represent a valuable immunotherapeutic intervention aiding in the treatment of chronic HIV-1 infection.