title: Cross-clade CD8(+) T-cell responses with a preference for the predominant circulating clade.
abstract: Human immunodeficiency virus (HIV) genetic diversity is a major impediment to the design of a successful vaccine. Even if an HIV vaccine is proven effective, it remains to be seen whether this protection will extend to inter-clade, intra-clade, and recombinant strains. We used recombinant vaccinia-based interferon gamma (IFN) Elispot assays to test the inter-clade crossreactivity of clades A, B, C, and D HIV Env in two cohorts of HIV-infected Kenyans. Despite the tremendous diversity in this HIV protein, a substantial proportion of multi-clade responses were observed. Although these multi-clade responses correlated well with each other in regression analyses, clade A responses were seen at a higher frequency and at greater relative magnitudes in a proportion of these patients, when compared to the other three clades. Epitope mapping indicates CD8(+) T cell recognition of conserved regions of Env, accounting for the high degree of cross-reactivity but not the clade A preference. A better understanding of cross-clade CD8(+) T cell responses to HIV may help to predict whether a successful vaccine could be used to stop geographically and genetically distinct HIV epidemics.
authors.affiliation: Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Lyle R
authors.initials: LR
authors.lastname: McKinnon
authors.forename: T Blake
authors.initials: TB
authors.lastname: Ball
authors.forename: Joshua
authors.initials: J
authors.lastname: Kimani
authors.forename: Charles
authors.initials: C
authors.lastname: Wachihi
authors.forename: Lucy
authors.initials: L
authors.lastname: Matu
authors.forename: Ma
authors.initials: M
authors.lastname: Luo
authors.forename: Joanne
authors.initials: J
authors.lastname: Embree
authors.forename: Keith R
authors.initials: KR
authors.lastname: Fowke
authors.forename: Francis A
authors.initials: FA
authors.lastname: Plummer
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D015331:Cohort Studies; D003429:Cross Reactions; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005260:Female; D014644:Genetic Variation / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007630:Kenya
chemical_list: D018984:Epitopes, T-Lymphocyte; D015699:HIV Envelope Protein gp120