Differences in immunoregulatory cytokine expression patterns in the systemic and genital tract compartments of HIV-1-infected commercial sex workers in Benin

Initial exposure to human immunodeficiency virus type 1 (HIV-1) during heterosexual transmission occurs in the genital tract. Although much of the literature on the immune response to HIV-1 infection is based on studies performed at the systemic level, our understanding of tissue-specific immunity is lacking. Levels of both genital mucosal and blood interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma production were compared between 57 HIV-1-uninfected and 52 HIV-1-infected female commercial sex workers (CSWs) as well as 73 HIV-1-uninfected non-CSW control women at low risk for exposure. HIV-1-infected CSWs had significantly higher genital mucosal levels of TNF-alpha and IFN-gamma compared with those in both the HIV-uninfected CSW and non-CSW groups. In contrast, the serum levels of all the cytokines tested were lower in HIV-1-infected CSWs compared with those in the other groups. The increased production of genital mucosal pro-inflammatory cytokines in HIV-1-infected CSWs possibly reflects susceptibility to HIV-1 infection and disease progression/perpetuation at the initial site of exposure.