Virus reactivation upon PD-L1 blockade is related to increased percentage of Treg cells.

(A) PBMCs were stimulated with Gag peptides in the presence of a PD-L1 blocking antibody or an isotype control antibody. After 4 days in culture, supernatants were harvest to quantify the p24 HIV core antigen by ELISA. The dashed line indicates the ELISA cut-off. Significant differences were determined by a Wilcoxon matched pairs test (*p <0.05; **p <0.01). Ild: inferior to the limit of detection. Panels B to E show correlations between fold change (FC) in p24 and fold change in percentage of proliferating CD4 T cells (B), percentage of Treg cells (including eTreg and rTreg) (C), fold change in the CD4 T cell to Treg cell (CD4/Treg) percentage ratio (D), and fold change in the CD8 T cell to Treg cell (CD8/Treg) percentage ratio (E); respectively. Spearman’s rank correlation coefficients (r) and p values (P) are indicated.