KSHV latent antigen-specificELISPOTanalysis of PBMCs from KSHV seropositive and seronegative donors. PBMCs from 14 KSHV seropositive donors (A) and 16 KSHV seronegative donors (B) were tested by IFN-γ ELISPOT against pools of overlapping peptides that spanned the KSHV latent antigens. Results are reported as number of spot-forming cells (SFC) per million PBMCs. Background responses to the DMSO control have been subtracted from the values presented; mean values were 10 and 3 SFC/million PBMCs for the seropositive and seronegative donors, respectively.