FIG. 2.

Decreasing frequencies of Gag-specific T-cell responses during the chronic phase of HIV infection. Gag peptide pool responses were detected at baseline and 9 months later with fresh PBMC and pools of consecutive overlapping 15-mer peptides in an IFN-γ ELISPOT assay. The proportion of Gag pool responses that either remained the same, increased in magnitude, were newly detected, were lost, or decreased in magnitude after a 9-month interval is shown. The estimated SD of the mean of ±16% for the quality control samples was used to define a range of “unchanged” as within 32% of the original response. Responses that changed over the 9 months by more than 32% were considered as decreased or increased.