[Specific immune responses to human immunodeficiency virus type 1 Gag, Tat, Rev and Nef proteins].

Aim: To investigate the features of HIV-1-Gag-, Tat-, Rev- and Nef- specific cytotoxic T-lymphocyte (CTL) responses in infected individuals in China.

Methods: The HIV-1-specific CTL responses were analyzed with an IFN-gamma ELISPOT assay by using 220 overlapping peptides spanning the entire HIV-1 Clade B (HIV-1B) and C (HIV-1C) Gag, Tat, Rev and Nef proteins consensus sequences.

Results: For either HIV-1B or HIV-1C, Gag and Nef were preferentially targeted by HIV-1 specific CTLs, Rev and Tat proteins were also recognized to different extent. In comparison of the immune responses between HIV-1B and HIV-1C, the magnitude and frequency were roughly identical but there were some differences in the immunodominant regions. For HIV-1B, the highest response magnitude was detected in 288-313 amino acids of Gag p24, and for HIV-1C, in 155-181 amino acids of Gag p24. The most frequently recognized region was located in 106-143 amino acids of Nef either in HIV-1B or in HIV-1C (48.1%).

Conclusion: HIV-1-specific CTLs mainly directed against HIV-1 Gag and Nef in Chinese, and there is some difference between HIV-1B and HIV-1C. There exists the cross-recognition between the Clade B and Clade C. These data suggest that the study on HIV-1-specific CTL responses in Chinese will provide strategies for the vaccine design in China.