HIV-1-specific mucosal IgA in a cohort of HIV-1-resistant Kenyan sex workers
Ngugi, Elizabeth N
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Objectives: Most HIV-1 transmission is sexual; therefore, immune responses in the genital mucosa may be important in mediating protection against HIV infection. This study examined HIV-1-specific mucosal IgA in a cohort of HIV-1-resistant Kenyan female sex workers. Methods: HIV-1-specific immune responses were compared in HIV-1-resistant and HIV-1-infected sex workers, and in lower risk uninfected women. Cervical and vaginal samples from each group were tested for HIV-1-specific IgA and IgG by enzyme immunoassay. Systemic T-helper lymphocyte cell responses to HIV-1 envelope peptide epitopes were assayed using an interleukin 2 bioassay. HIV-1 risktaking behaviours were assessed using standardized questionnaires. Results: HIV-1-specific IgA was present in the genital tract of 16 out of 21 (76%) HIV-1-resistant sex workers, five out of 19 (26%) infected women, and three out of 28 (11%) lower risk women (P < 0.0001). Among lower risk women, the presence of HIV-1-specific IgA was associated with HIV-1 risk-taking behaviour. Systemic T-helper lymphocyte responses to HIV-1 envelope peptides were present in 11 out of 20 (55%) HIV-1-resistant women, four out of 18 (22%) infected women, and one out of 25 (4%) lower risk women (P < 0.001). T-helper lymphocyte responses did not correlate with the presence or titre of virus-specific mucosal IgA in any study group. Conclusions: HIV-1-specific IgA is present in the genital tract of most HIV-1- resistant Kenyan sex workers, and of a minority of lower risk uninfected women, where it is associated with risk-taking behaviour. These data suggest a role for mucosal HIV-1-specific IgA responses in HIV-1 resistance, independent of host cellular responses.
CitationAIDS. 1999 Jan 14;13(1):23-9
Department of Medical Microbiology and Community Health, University of Nairobi, Nairobi, KenyaDivision of Infectious Diseases, Department of Medicine, University of Toronto, Canada,The Cattedra di Immunologia, Universita degli Studi di Milano, Milan, ItalyDepartment of Medical Microbiology, University of Manitoba, Winnipeg, Canada
Commercial sex workers