HIV-1 protective epitope-specific CD8+ T cells in HIV-1-exposed seronegative individuals

Abstract

Although previous studies have reported HIV-1-specific Tcell responses in HIV-1-exposed seronegative (HESN) individuals, there has been no detailed analysis of these Tcells against HIV-1 infection. We investigated HIV-1-specific CD8+ Tcell responses in 200 Japanese HESN men who have sex with men (MSM). Tcell responses to 143 well-characterized HIV-1 epitope peptides were analyzed by intracellular cytokine staining assay consisting of 3-week cultures of PBMCs stimulated with peptides. HLA-B∗51:01-restricted Pol TI8-specific and HLA-A∗02:06-restricted Pol SV9-specific CD8+ Tcells were identified in two and one individuals, respectively, whereas CD8+ Tcells specific for other HLA-A∗02:06-restricted or HLA-B∗51:01 epitopes were not present in these individuals. These epitope-specific Tcells recognized HIV-1-infected cells. Because these two epitopes were previously reported to be protective in HIV-1-infected individuals, these protective epitope-specific Tcells might suppress HIV-1 replication in HESN-MSM individuals. The present study suggests the contribution of protective epitope-specific Tcells to protection against HIV-1 infection.