Increase in IFN-γ–producing effector/memory (E/M) CD8 T cells significantly correlates with disease duration in virus-inoculated marmosets. (A) Representative flow cytometry plot of CD8+ CD45RA/CD27 T cell subsets, with histogram showing highest IFN-γ production by E/M subset. E, effector; M, memory. (B) Representative flow cytometry plots showing a decrease in naïve CD8+ T cells at terminal EAE time points in virus/EAE, but not control/EAE, marmosets. (C and D) Contraction of naïve CD8 (C) and expansion of E/M CD8 (D) T cells correlate with EAE disease duration in virus-inoculated marmosets. (E and F) In the control/EAE marmosets, no such correlation was observed for either the naïve CD8 (E) or the E/M CD8 (F) subset.