FIG. 5.

Effector cells generated by HIV-1 Gag peptide stimulation of PBMC are more effective than those generated by stimulation of PBMC with recombinant vaccinia virus–HIV-1 gag for lysing target cells infected with vaccinia virus–HIV-1 gag. Aliquots of PBMC from chimpanzees C-487 and C-1196 were stimulated with paraformaldehyde-fixed, autologous B-LCL infected with vaccinia virus–HIV-1 gag. Other aliquots of these PBMC were stimulated with the appropriate HIV-1 Gag peptide. On day 3 of culture, 20 U of recombinant human interleukin-2 per ml was added to the cultures. On day 12 of culture, the lymphocytes were assessed as effector cells in cytotoxicity assays using as target cells ⁵¹Cr-labeled autologous B-LCL infected with vaccinia virus–HIV-1 gag. Lysis of the vaccinia virus–HIV-1-gag-infected targets by recombinant vaccinia virus–HIV-1-gag-stimulated PBMC is represented by filled squares, whereas filled triangles show lysis by effectors generated by stimulation of PBMC with HIV-1 Gag peptides.