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

Illustrating the importance of these combined Gag-specific T cell responses over time, low viraemia was intermittently detected at earlier time points in C122, with sharp increases in Gag CTL temporally associated with control of transient viraemia at 17 years post infection. However, Gag CTL later failed to contain viraemia in C122 beyond approximately 20 years, coinciding with weakening proliferative responses that gradually became negative. A similar correlation between anti viral immune responses and a spike in viral replication was demonstrated in SBBC member C18, shown in more detail in Figure 3 . Over the course of 12 months, in response to an increase in viraemia peaking at 3600 copies/ml, the p24 proliferative response increased, along with substantial expansions of Pol-specific CTL in both precursor [15] and effector CTL populations. The durability of immune control in this individual was not determined as he died soon after from causes unrelated to HIV disease, aged 83.