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

While host genetic factors may predispose an individual for delayed disease progression, there is substantial evidence that antiviral T cell responses are required to sustain non-progressor status. Earlier studies have demonstrated an important role for Gag-specific CTL in delaying disease progression [20, 21] . Non-progressors that control viraemia in the absence of antiviral therapy also have strong CD4 T cell proliferative responses to the Gag protein p24 [22] . Importantly, for Gag CTL to be efficient in killing HIV-infected cells and therefore protective in controlling viraemia, these must also be accompanied by p24-specific T cell proliferative responses [23] [24] [25] . Appropriate T cell help is also required to achieve maturation and display of effector phenotypes on CTL associated with effective virological control [26] .