FIG 4.

VSV-gp160G is capable of inducing apoptosis in ATL cells and depends upon CD4 and gp120 interaction. (A and B) ATL cells were infected with either VSV-XN2 or VSV-gp160G at an MOI of 0.01. Cells and supernatants were collected at 6, 12, 24, and 48 hpi. Cell death at each time point was determined by using annexin V-PI staining. Representative gating results are shown. (C) Bright-field microscopy of infected ATL cells pretreated with neutralizing antibody against CD4 (1 μg/well, MT-2, MT-4, TLO-m1) or gp120 (2 μg, VSV inoculum) for 1 h prior to infection at an MOI of 0.01. MT-2 and MT-4 cells were assessed at 24 hpi, and TLO-m1 cells were assessed at 96 hpi. (D) Cell death of infected ATL cells pretreated with neutralizing antibody was determined using annexin V-PI staining at 24 hpi. MT-2, MT-4, or TLO-m1 cells were infected with VSV-XN2 at an MOI of 0.5, 0.01, or 0.05, respectively, or infected with VSV-gp160G at an MOI of 0.1, 0.01, or 0.5, respectively. (Student t test, two tailed, equal variance; *, P < 0.01; **, P < 0.001 [panel D, untreated control versus antibody treated]).