Mechanisms of HIV non-progression; robust and sustained CD4+ T-cell proliferative responses to p24 antigen correlate with control of viraemia and lack of disease progression after long-term transfusion-acquired HIV-1 infection

Dyer, Wayne B; Zaunders, John J; Yuan, Fang Fang; Wang, Bin; Learmont, Jennifer C; Geczy, Andrew F; Saksena, Nitin K; McPhee, Dale A; Gorry, Paul R; Sullivan, John S

The other distinguishing feature of most slow and nonprogressor subjects that we have studied is the predominance of Gag CTL, but the SBBC non-progressors were exceptional in having a Pol-dominant CTL response. This observation is unexpected, considering the extensively published role for Gag CTL in controlling viraemia [20, 21, 23] . Also peculiar to SBBC members, the strongest CTL responses were detected in those with detectable viraemia, and were weaker in subjects with undetectable viraemia [15] . In the non-attenuated HIV-infected nonprogressors, strong immunodominant CTL combined with detectable proliferative responses to p24 appears to have contributed to viraemia remaining <100 copies/ml after 23 years HIV-1 infection in patient C53. The individual with the strongest CTL response was C122, but CTL increased as viraemia increased in this patient, while proliferative responses to Gag p24 declined. Given the predominant CTL response in this subject was directed against an immunodominant HLA B27 restricted p24