VAMP8 does not colocalize with cytotoxic granule constituents in human CTLs. (A and B) SIM images depicting VAMP8 localization in unconjugated (A) or SEA-target cell-conjugated (B) human CTLs stained with anti-VAMP8 and anti–granzyme B (GzmB). (C and D) SIM images depicting VAMP8 localization in unconjugated (C) or SEA-target cell-conjugated (D) CTLs stained with anti-VAMP8 and anti-perforin. (C) SIM images of resting human CTL stained with anti-VAMP8 and anti-perforin. For SEA-target cell-conjugated CTLs, the Pearson’s coefficient for VAMP8 versus perforin was r = 0.28 (n = 10). Bars, 2.5 µm.