title: HIV-1-specific mucosal IgA in a cohort of HIV-1-resistant Kenyan sex workers.
abstract: OBJECTIVE
  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 risk-taking 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.
authors: Department of Medical Microbiology and Community Health, University of Nairobi, Kenya.
authors: R
authors: R
authors: Kaul
authors: D
authors: D
authors: Trabattoni
authors: J J
authors: JJ
authors: Bwayo
authors: D
authors: D
authors: Arienti
authors: A
authors: A
authors: Zagliani
authors: F M
authors: FM
authors: Mwangi
authors: C
authors: C
authors: Kariuki
authors: E N
authors: EN
authors: Ngugi
authors: K S
authors: KS
authors: MacDonald
authors: T B
authors: TB
authors: Ball
authors: M
authors: M
authors: Clerici
authors: F A
authors: FA
authors: Plummer
mesh_terms: D018791:CD4 Lymphocyte Count; D002584:Cervix Uteri / Q000276:immunology*; D015331:Cohort Studies; D005260:Female; D015483:HIV Antibodies / Q000276:immunology*; D015658:HIV Infections / Q000453:epidemiology / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology; D007070:Immunoglobulin A / Q000276:immunology*; D007074:Immunoglobulin G; D007630:Kenya / Q000453:epidemiology; D009092:Mucous Membrane / Q000276:immunology; D011477:Sex Work; D014621:Vagina / Q000276:immunology*
chemical_list: D015483:HIV Antibodies; D007070:Immunoglobulin A; D007074:Immunoglobulin G