Figure 5.

Apoptotic cells provide a stronger adjuvant effect. (A) A20 cells were treated at 37°C with 10 ng/ml Fas ligand (Alexis, San Diego) followed by an anti-Fas ligand antibody and incubated for 4 h. A portion of the cells was used for flow cytometry (see E) and the remainder was frozen and thawed; the indicated number of cell equivalents were coinjected with gp120/latex beads into BALB/c mice. The priming of anti-gp120 CTLs was determined as described in Fig. 1C. (B) Same as A except cells were treated with emetine (20 μM). (C) Same as A except cells were treated with oligomycin (25 μM) for at least 7 h. (D) Same as A except cells were untreated. (E) Treated and untreated cells were stained with Annexin V and propidium iodine (PI) and analyzed by flow cytometry. All Fas ligand-treated cells were Annexin V positive with a 30 min longer incubation (at the time of harvesting for injection, data not shown). 3T3 cells treated with UV as in Fig. 4A also become Annexin V+, PI- (data not shown). E:T ratio, effector-to-target cell ratio.