Cross-clade CD8 T-cell Responses to HIV_IIIB and Chinese B’ and C/B’ viruses in north American and Chinese HIV-Seropositive Donor

Francois-Bongarcon V., Yi Feng, Sang-Kyung Lee, Gang Chen, Premlata Shankar, Ying Liu, Xin Tao, Yiming Shao, Judy Lieberman

Summary: 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 HIVⅢB 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-g production in response to HIVⅢB or the Chinese viruses was comparable. Although 1.6±0.8% of American donor CD8 T cell produced IFN-g 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-g 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.

Key word: HIV, vaccine, CD8 T lymphocyte, cytolysis, IFN-g, cross-clade