title: Quantitative ex vivo analysis of functional virus-specific CD8 T lymphocytes in the blood and genital tract of HIV-infected women.
abstract: BACKGROUND
  CD8 T lymphocytes are important in HIV-1 control and mediate virus-specific immunity in the blood and genital tract. The induction and monitoring of mucosal CD8 cell responses will be an important component of HIV-1 vaccine trials, but information regarding the frequency, phenotype and function of genital tract CD8 cell responses is lacking.
  
  
  METHODS
  Simultaneous blood and cervical cytobrush samples were obtained from 16 HIV-1-infected Kenyan sex workers. Epitope-specific CD8 T lymphocyte frequencies in the blood and genital tract were analysed after short-term peptide incubation and intracellular cytokine staining for interferon-gamma (IFN gamma).
  
  
  RESULTS
  Cervical sampling resulted in adequate cell numbers for analysis in 10/16 women. Background IFN gamma production was higher in CD3+/CD8+ lymphocytes from the genital tract than from blood (0.48% versus 0.1%; P < 0.01). Responses to staphylococcal enterotoxin B were detected in cervical CD8 lymphocytes from 10/10 women, at a similar frequency to blood (16.7% in cervix and 13.3% in blood; P = 0.4). HIV-1-specific responses were detected the cervix of 8/10 women, with a trend to higher response frequencies in the genital tract than blood (2.1% versus 0.8%; P = 0.09). Co-expression of integrin CD103 (alpha E beta 7), a mucosal marker, was used to confirm the mucosal origin of cervical responses.
  
  
  CONCLUSIONS
  Cytobrush sampling and intracellular cytokine staining is well suited to the analysis of cervical CD8 cell responses. The frequency of functional virus-specific CD3+/CD8+ T cells is similar in the genital tract and blood of HIV-1-infected women. The role of genital tract CD8 cell responses in HIV-1 control warrants further investigation.
authors.affiliation: Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya.
authors.forename: Rupert
authors.initials: R
authors.lastname: Kaul
authors.forename: Paul
authors.initials: P
authors.lastname: Thottingal
authors.forename: Joshua
authors.initials: J
authors.lastname: Kimani
authors.forename: Peter
authors.initials: P
authors.lastname: Kiama
authors.forename: Charles W
authors.initials: CW
authors.lastname: Waigwa
authors.forename: Job J
authors.initials: JJ
authors.lastname: Bwayo
authors.forename: Francis A
authors.initials: FA
authors.lastname: Plummer
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Rowland-Jones
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002584:Cervix Uteri / Q000276:immunology*; D004768:Enterotoxins / Q000276:immunology; D005260:Female; D015658:HIV Infections / Q000276:immunology* / Q000635:transmission; D015497:HIV-1; D006801:Humans; D018928:Immunity, Mucosal; D007371:Interferon-gamma / Q000096:biosynthesis; D011477:Sex Work
chemical_list: D004768:Enterotoxins; C031818:enterotoxin B, staphylococcal; D007371:Interferon-gamma