Cross-clade CD8 T-cell responses to HIV(IIIB) and Chinese B' and C/B' viruses in North American and Chinese HIV-seropositive donors

HIV variation presents an obstacle to a global AIDS vaccine. Viral diversity and host variations in MHC expression both affect vaccine responses. Whether CD8 T cells from HIV-infected donors in 1 part of the world cross-recognize isolates from other regions will provide guidance about whether country-specific vaccines are needed. We compared recognition of HIV(IIIB) and representative B' (Thai B) and recombinant C/B' virus strains endemic in China by CD8 T cells from 7 HIV-infected North American donors and 4 Chinese donors. IFN-gamma production in response to HIV(IIIB) or the Chinese viruses was comparable. Although 1.6 +/- 0.8% of American donor CD8 T cells produced IFN-gamma above the background level in response to IIIB virus, 1.5 +/- 0.8% responded to B' virus, and 1.4 +/- 0.7% responded to C/B' virus. Responses to adherent cells infected with vaccinia viruses expressing B' and C/B' virus gag and env were also comparable in magnitude with responses to IIIB virus. Cytolysis of CD4 T cells infected with B' virus was comparable with lysis of cells infected with IIIB virus, but lysis of the more divergent C/B' virus was somewhat reduced. T cells, selected for IFN-gamma production to IIIB virus, also efficiently lysed cells infected with Chinese viruses. Therefore, cross-clade CD8 T-cell responses to IIIB virus and prevalent Chinese viral strains are common.