Acute phase CTL responses against ARF-10 in two SIV-infected Rhesus macaques.
A) and B) Magnitude of CTL responses against 15-mers in ARF-10 in Rhesus macaques rh2261, A, and r04028, B, as measured by IFN–γ ELISPOT using cryopreserved PBMC harvested 3 weeks after initial SIV infection. The SIV infection history of the animals is described in the text. Bars are color coded to match with remaining panels in the figure. C) and D) Peptide dilutions to fine map the minimal optimal epitopes targeted in ARF-10 by rh2261, C, and r04028, D. For rh2261, we used PBMC harvested in the acute phase of infection. For animal r04028, due to PBMC sample limitations, we expanded antigen-specific CTL by exposing PBMC to autologous irradiated BLCL pulsed with the responsive 15-mer for several weeks and used these cells in an ELISPOT. For panels A–C, we used 100,000 PBMC per well, in duplicate, in ELISPOT plates. For the epitope mapping with r04028, we used 20,000 antigen-specific cells per well combined with 10,000 autologous BLCL per well as antigen presenting cells. Peptides tested are shown at right of each mapping panel and the peptides we determined represented the minimal epitopes are shown in color to match panels A and B. E) The mapped epitopes within ARF-10 are boxed using the color scheme described above.