title: Elevation of immune activation in kenyan women is associated with alterations in immune function: implications for vaccine development.
abstract: The infectious burden leading to immune activation can vary between different populations and lead to various immune dysfunctions. We compared the effect of immune activation on apoptosis and T cell function in HIV uninfected individuals from Nairobi, Kenya (n=34), and Winnipeg, Canada (n=10). Women from Nairobi had a significantly greater number of CD8+ T cells expressing the activation markers CD38 and HLA DR. Kenyan women also had significantly higher levels of CTLA-4+ CD4 and CD8+ T cells, and reduced levels of CD28+ CD8+ cells. Levels of CD95+ CD4+ T cells were higher in Kenyan women and, correspondingly, showed higher levels of spontaneous apoptosis. Kenyan women also demonstrated hyper-responsiveness to T cell activation as assessed by interferon gamma production. This study demonstrates that in a population of Kenyan women with high levels of T cell activation, there were also elevated levels of T cell apoptotic death and hyper-responsiveness. These differences may influence the efficacy of immune responses to pathogens and must be considered when testing candidate vaccines.
authors.affiliation: Department of Medical Microbiology, University of Manitoba, William Avenue, Winnipeg, MB, Canada.
authors.forename: Sandra A
authors.initials: SA
authors.lastname: Koesters
authors.forename: Lucy
authors.initials: L
authors.lastname: Matu
authors.forename: Peter
authors.initials: P
authors.lastname: Kiama
authors.forename: Omu
authors.initials: O
authors.lastname: Anzala
authors.forename: Joanne
authors.initials: J
authors.lastname: Embree
authors.forename: Francis A
authors.initials: FA
authors.lastname: Plummer
authors.forename: Joshua
authors.initials: J
authors.lastname: Kimani
authors.forename: Keith R
authors.initials: KR
authors.lastname: Fowke
mesh_terms: D017209:Apoptosis / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002170:Canada / Q000208:ethnology; D005006:Ethnicity; D005260:Female; D006801:Humans; D007109:Immunity; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000096:biosynthesis; D007630:Kenya / Q000208:ethnology; D008213:Lymphocyte Activation / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D014612:Vaccines / Q000276:immunology*
chemical_list: D014612:Vaccines; D007371:Interferon-gamma