Integrin αβ expression on peripheral blood CD4 T cells predicts HIV acquisition and disease progression outcomes.

The gastrointestinal (GI) mucosa is central to HIV pathogenesis, and the integrin αβ promotes the homing of immune cells to this site, including those that serve as viral targets. Data from simian immunodeficiency virus (SIV) animal models suggest that αβ blockade provides prophylactic and therapeutic benefits. We show that pre-HIV infection frequencies of αβ peripheral blood CD4 T cells, independent of other T cell phenotypes and genital inflammation, were associated with increased rates of HIV acquisition in South African women. A similar acquisition effect was observed in a Kenyan cohort and in nonhuman primates (NHPs) after intravaginal SIV challenge. This association was stronger when infection was caused by HIV strains containing V2 envelope motifs with a preference for αβ binding. In addition, pre-HIV αβ CD4 T cells predicted a higher set-point viral load and a greater than twofold increased rate of CD4 T cell decline. These results were confirmed in SIV-infected NHPs. Increased frequencies of pre-HIV αβ CD4 T cells were also associated with higher postinfection expression of lipopolysaccharide binding protein, a microbial translocation marker, suggestive of more extensive gut damage. CD4 T cells expressing αβ were rapidly depleted very early in HIV infection, particularly from the GI mucosa, and were not restored by early antiretroviral therapy. This study provides a link between αβ expression and HIV clinical outcomes in humans, in line with observations made in NHPs. Given the availability of a clinically approved anti-αβ monoclonal antibody for treatment of inflammatory bowel disease, these data support further evaluation of targeting αβ integrin as a clinical intervention during HIV infection.