CMV-specific CD8+ T lymphocyte memory responses to RhCMV immediate early (IE) proteins and exogenous SIV Gag protein in CD4+ T lymphocyte depleted RhCMV reinfected macaques.

(A) Paired IE-specific responses by CD107a expression and secretion of IFN-γ, IL-2, and TNF-α in four CMV-seropositive macaques reinfected with RhCMV UCD52 and FL-RhCMVΔRh13.1/SIVgag (n = 3) or RhCMV 180.92 (n = 1). Pre-reinfection responses were compared with responses at week 8–10 post RhCMV reinfection using paired t-test. (B) Polyfunctional SPICE analysis of IE-specific responses pre vs post RhCMV reinfection showing the proportion of four-functional, three-funtional, two-functional and single function responses. CD107a (blue arc), IFN-γ (red arc), IL-2 (orange arc), and TNF-α (green arc). Four-functional responses are displayed in white, three-functional responses in dark grey, two-functional response in light grey, and mono-functional responses in black. (C) Bar graph of the polyfunctional responses pre (grey) and post (black) RhCMV reinfection (n = 4) showing the frequency of memory CD8+ T lymphocytes responding to RhCMV IE peptides. The RhCMV IE-specific response was measured by intracellular cytokine staining after stimulation with RhCMV IE1 and / or IE2 peptide pools depending on the baseline immunodominant response in individual animals. Comparison of pre- and post reinfection Boolean responses were compared with the Wilcoxon rank sum test using SPICE v6 software.