Summary ELISPOT data. PBMC from HTLV-1-infected and uninfected subjects were screened with the indicated peptides in IFN-γ ELISPOT assays. In the cases of HERV-K-Env, HERV-K-Gag and HERV-Opt the mean background (0.5% DMSO) subtracted responses to individual peptide pools (18 pools for Env, 17 pools for Gag, 4 pools for Opt) were summed to give a total response. Responses are expressed as spot forming units (SFU) per million PBMC. P values were calculated using Student’s T-test.