FIG. 6.

SIV-specific cytotoxic activities against SIV gag- and env-expressing target cells were detected in the primary IEL. Primary IEL from a rhesus macaque at 4 weeks p.i. were cultured overnight in RPMI 1640 medium supplemented with 10% FCS, antibiotics, and 5% human lymphocyte-conditioned medium and 20 U of recombinant human IL-2 per ml. Autologous B lymphocytes were transformed by herpesvirus papio and infected overnight with wild-type vaccinia virus (vvWR) or recombinant vaccinia virus expressing the SIV major core protein, p55^gag (vvgag), or envelope glycoprotein, gp160^env (vvenv), of SIVmac239. Effector and target cells were added together at multiple E:T ratios in a 4-h chromium release assay, and percent specific lysis against WR (▪), gag (•)-, and env (✚)-expressing target cells was calculated.