A Correlate of HIV-1 Control Consisting of Both Innate and Adaptive Immune Parameters Best Predicts Viral Load by Multivariable Analysis in HIV-1 Infected Viremic Controllers and Chronically-Infected Non-Controllers

HIV-1 infected viremic controllers maintain durable viral suppression below 2000 copies viral RNA/ml without anti-retroviral therapy (ART), and the immunological factor(s) associated with host control in presence of low but detectable viral replication are of considerable interest. Here, we utilized a multivariable analysis to identify which innate and adaptive immune parameters best correlated with viral control utilizing a cohort of viremic controllers (median 704 viral RNA/ml) and non-controllers (median 21,932 viral RNA/ml) that were matched for similar CD4 + T cell counts in the absence of ART. We observed that HIV-1 Gag-specific CD8 + T cell responses were preferentially targeted over Pol-specific responses in viremic controllers ( p = 0.0137 ), while Pol-specific responses were positively associated with viral load (rho = 0.7753, p = 0.0001 , n = 23). Viremic controllers exhibited significantly higher NK and plasmacytoid dendritic cells (pDC) frequency as well as retained expression of the NK CD16 receptor and strong target cell-induced NK cell IFN-gamma production compared to non-controllers ( p<0.05 ). Despite differences in innate and adaptive immune function however, both viremic controllers ( p<0.05 ) and non-controller subjects ( p<0.001 ) exhibited significantly increased CD8 + T cell activation and spontaneous NK cell degranulation compared to uninfected donors. Overall, we identified that a combination of innate (pDC frequency) and adaptive (Pol-specific CD8 + T cell responses) immune parameters best predicted viral load (R 2  = 0.5864, p = 0.0021, n = 17 ) by a multivariable analysis. Together, this data indicates that preferential Gag-specific over Pol-specific CD8 + T cell responses along with a retention of functional innate subsets best predict host control over viral replication in HIV-1 infected viremic controllers compared to chronically-infected non-controllers.