Robust Gag-specific T cell responses characterize viremia control in HIV-2 infection

Journal article

HIV-2 infection in the majority of infected subjects follows an attenuated disease course that distinguishes it from infection with HIV-1. Antigen-specific T cells are pivotal in the management of chronic viral infections but are not sufficient to control viral replication in HIV-1-positive subjects, and their function in HIV-2 infection is not fully established. In a community-based cohort of HIV-2 long-term nonprogressors in rural Guinea-Bissau, we performed what we believe is the first comprehensive analysis of HIV-2-specific immune responses. We demonstrate that Gag is the most immunogenic protein. The magnitude of the IFN-γ immune response to the HIV-2 proteome was inversely correlated with HIV-2 viremia, and this relationship was specifically due to the targeting of Gag. Furthermore, patients with undetectable viremia had greater Gag-specific responses compared with patients with high viral replication. The most frequently recognized peptides clustered within a defined region of Gag, and responses to a single peptide in this region were associated with low viral burden. The consistent relationship between Gag-specific immune responses and viremia control suggests that T cell responses are vital in determining the superior outcome of HIV-2 infection. A better understanding of how HIV-2 infection is controlled may identify correlates of effective protective immunity essential for the design of HIV vaccines.

Authors: Leligdowicz, A; Yindom, L; Onyango, C; Sarge-Njie, R; Alabi, A

• Journal: Journal of Clinical Investigation
• Volume: 117
• Issue: 10
• Pages: 3067-3074
• Publication date: 2007-10-01
• DOI: 10.1172/JCI32380
• EISSN: 1558-8238
• ISSN: 0021-9738
• Language: English