FIG. 2.

Titration of the CD8⁺ T-cell response to the original Gag 114 peptide, the resynthesized Gag 114 peptide, and the HCMV-NV9 peptide. Autologous BLCL were pulsed with serial 10-fold dilutions of each peptide and then used as antigen-presenting cells in a CFC assay for IFN-γ up-regulation in cryopreserved PBMC from a known HIV-1-seronegative, HCMV-NV9 responder subject. Results are expressed as the percentages of IFN-γ-positive cells in the CD3⁺ CD8⁺ T-cell population. The dotted line shows the interpolated peptide concentration at which the 50% maximal response to the HCMV-NV9 peptide occurred.