Fig 9. Comparison of strong and weak cellular vaccine response within TV+TLR7 infant RMs.

(A) Magnitude of anti-SIV cellular immunity measured by IFN-γ ELISPOT prior to ATI at 62 weeks post infection of strong and weak responders. Dashed bars represent median. Groups were compared using a two-sided Mann-Whitney test (P < 0.05 was considered significant). (B) Pie charts depicting the ability of memory CD8⁺ and CD4⁺ T cells isolated from strong and weak TV+TLR7 responders to produce IFN-γ, IL-2 and/or TNF-α in response to stimulation with SIVmac239 Gag peptide pool at 52 weeks post infection (n = 4). (C) Longitudinal analysis of HLA-DR and PD-1 expression on effector memory (EM) and central memory (CM) CD8⁺ T cells in strong and weak responders within TV+TLR7 RMs (n = 8). The shaded area represents the period of ART treatment. AUC on ART was compared between groups using a two-sided Mann-Whitney test. (P < 0.05 was considered significant) Association between (D) HLA-DR expression on EM, (E) PD-1 expression on CM, and (F) PD-1 expression on EM CD8⁺ T cells during ART represented by AUC and magnitude of SIV-specific T cells following end of vaccine regimen prior to ATI measured by ELISPOT in TV+TLR7 RMs. Two-sided Spearman rank correlation test was used to determine statistical significance. R value indicates correlation coefficient. (G) Comparison of time to viral rebound in strong and weak TV+TLR7 responder RMs depicted by Kaplan-Meier curves. (H) Median longitudinal plasma SIV RNA levels between strong and weak responders following ATI. The solid line represents the median, the shaded area represents interquartile range, and the horizontal dashed line represents the limit of detection of the assay. (I) Set point viremia following 16 weeks of ATI of strong and weak TV+TLR7 responders determined by the mean of the final three viral load measurements. Dashed bars represent median. Groups were compared using a two-sided Mann-Whitney test (P < 0.05 was considered significant).