Evolution of the epitope specificity of SIV-specific CD8 T cell responses in SIVΔnef-vaccinated animals.

(A) The total magnitude of the PBMC CD8 T cell response as measured by IFN-γ ELISPOT assays using whole protein overlapping peptide pools. (B) The breadth of the PBMC CD8 T cell response as measured by the average number of positive pools at weeks 5 and 20. (C) The magnitude and the breadth of lymph node CD8 T cell responses. The total magnitude of lymph node CD8 T cell response to SIV was determined by adding the responses for all 30 peptide pools spanning the entire SIVΔnef proteome. (D) The Gag and Pol-specific CD8 T cell response as a fraction of the total SIV-specific CD8 T cell response increased significantly between weeks 5 and 16/20 (p<0.0001), plateauing at week 16.