CE-specific responses are recognized by CD8 T cells in HIV-1 infection. (A) An IFN-γ ELISPOT assay using antigen-specific stimulation in duplicate was used to determine the magnitude of T cell responses in primary (PHI; n = 24) and chronic (CHI; n = 41) HIV-1 subtype B–infected patients. These responses were compared with SN controls (n = 15). Each symbol represents the response magnitude to an individual CE. The dotted line indicates the cutoff for a positive response (>55 SFCs/10⁶ PBMCs), and horizontal bars represent medians. (B) The percentage of patients or peptides that elicited a CE-specific response are shown. The percent positive is shown on top of the bar.