PBMCs from an HIV-infected patient (patient A17) were cultured for 10 days in medium alone, or with 10 nmol/l αCD40.HIV5pep and then rechallenged for 6 h with or without gag17, nef66 and pol325 HIV long peptides in the presence of brefeldin A prior to intracellular cytokine staining. The FACS plots show coordinate analysis of IFNγ versus CD107a externalization (a), or IFNγ versus granzyme B (b), or IFNγ versus perforin (c). The profiles are gated on the overall CD8+ T-cell population, with the percentage of populations responding to the designated peptides shown in each plot. Data are representative of two to three independent experiments using three different patients. The scales are log10 from 0 to 105, and in some cases bi-exponential transformation was applied.