The viral load during the early stages of infection inversely correlated with number of CL-10–specific tetramer-positive CD8⁺CTLs in colonic lamina propria before SHIV challenge, but not in blood. (A) Correlation between log viral load in blood on day 17 and number of CL-10–specific tetramer-positive CD8⁺CTLs in colonic lamina propria before SHIV challenge. (B) Correlation between log viral load in blood on day 17 and number of CL-10–specific tetramer-positive CD8⁺CTLs in peripheral blood before SHIV challenge. (C) Correlation between CL-10–specific perforin-positive CD8⁺ T cells in peripheral blood and log viral load in blood on day 17. Animal (67M) in group 2 with more than 1600 spots/million cells was included in determining the correlation but is not shown on this scale.