Association of drug abuse with inhibition of HIV-1 immune responses: Studies with long-term of HIV-1 non-progressors

Recreational drug use has been proposed to affect the course of human immunodeficiency virus (HIV) infections. To investigate the effects of substance abuse on HIV infections, we compared virus-specific cytotoxic T lymphocyte (CTL) responses and the expression of IL-16, TGF-β1, and CXCR4 in three different cohorts of HIV-infected patients: (1) long-term nonprogressors (LT-NPs) of HIV infection who do not use recreational drugs; (2) nondrugs using normal progressors (NPs), and (3) drugs using NPs. Our results show that LT-NPs manifest increased CTL activity and IL-16 expression and decreased expression of TGF-β1 and CXCR4 compared to NPs, regardless of recreational drug usage. Furthermore, drugs using NPs showed significantly lower levels of CTL and IL-16 expression and increased TGF-β1 and CXCR4 expression compared to nondrugs using NPs. Our results suggest that recreational drug use may reduce CTL and IL-16 expression and increase the expression of TGF-β1 and CXCR4, all of which may facilitate progression of HIV infections.