Absence of specific mucosal antibody responses in HIV-exposed uninfected sex workers from the Gambia

Objectives: Specific antibodies to HIV envelope that inactivate virus at th e mucosal surfaces involved in sexual contact are of interest for the desig n of a vaccine against HIV-1. It has been suggested that, in frequently HIV -exposed but uninfected individuals, HIV-specific mucosal antibody response s may exist and play a role in resistance against HIV. This study investiga ted HIV-1 envelope specific mucosal antibody responses in HIV-resistant sex workers in west Africa. Methods: A group of 26 exposed uninfected female commercial sex workers fro m the Gambia, who have had repeated exposures to HIV-1 and HIV-2 were studi ed. We assessed the presence of vaginal IgA and Ige in vaginal swabs agains t a range of HIV-1 and HIV-2 envelope presentations and performed HIV-1 neu tralization assays. Results: No significant vaginal IgA or Ige responses against HIV-1 or HIV-2 were detected, and none of the vaginal secretions tested displayed any HIV -1 neutralizing activity. Conclusion: Vaginal antibody responses against HIV were not found in Gambia n sex workers who resist HIV infection. Resistance against HIV infection ca n therefore occur in the absence of specific antibodies against HIV at the genital mucosa. A protective role for HIV-envelope specific IgA in resistan ce against HIV-1 infection in exposed uninfected individuals as reported in the literature is uncertain. (C) 2000 Lippincott Williams & Wilkins.