Magnitude of SIV-specific CD4⁺ and CD8⁺ cellular responses in rYF17D/rAd5 and rAd5 vaccinees.

<p>At one week after the rAd5 vaccination, we obtained PBMC from all animals and performed ICS to determine the frequency of IFN-γ-producing CD8⁺ (A and B) and CD4⁺ (C and D) lymphocytes specific to Gag (black bars), Nef (gray bars), Vif (plaid bars), and the combination of Tat, Rev, Vpr, and Vpx (white bars). The antigen stimuli in this assay consisted of peptide mixtures spanning (i) amino acids 1–291 of Gag, (ii) amino acids 281–510 of Gag, (iii) the Vif ORF, (iv) the Nef ORF, (v) the Tat ORF, (vi) the Rev ORF, and (vii) the Vpr and Vpx ORFs. Reactivity to the Gag protein is reported as the sum of tests (i) and (ii); reactivity to Tat, Rev, Vpr, and Vpx is reported as the sum of tests (v), (vi), and (vii). A and C show the results for the rYF17D/rAd5 group while B and D show results for the rAd5 group.