A. Representative flow cytogram from a healthy control showing the gating scheme for PD-1, coexpression of PD-1 and PD-L1 on CD4+ T cells and PD-L1 expression on monocytes; B. Expression of PD-1 (MFI) on CD8+ T cells in viremic and aviremic patients and healthy controls (HC); C. PD-1 expressing CD8+ T cells had a positive correlation with viral load (r = 0.366, P<0.05, dotted line) and negative correlation with CD4+ T cell counts (r = − 0.11, ns, bold line); D. PD-1 expressing CD8+ T cells had a positive correlation with HLA-DR and CD38 on CD8+ T cells (r = 0.5, P<0.05); E. PD-1 expression on CD8+ T cells decreased after 48 weeks on ART; ns, not significant; *, P<0.05.