TABLE 1.

Differences between the infectivities of wild-type and vif-deleted HIV gpt virions produced from heterokaryons assayed on HeLa-CD4 cells

Expta	Time of virus harvest (h)b	HIV gpt infection (no. of colonies/dish)c
		Wild type	vif deleted
1	24	20	0
	48	13	0
	72	4	0
2	24	36	7
	48	10	0
	72	2	0
3	24	41	7
	48	16	3
	72	10	3
4	48	110	0
	48	39	0
	48	34	0

^aIn experiments 1, 2, and 3, H9-42 cells that expressed high levels of CD4 were used for coculturing with HeLa-tc-gp160 cells. H9-42 cells were made by transducing H9 cells with pSFF-CD4 retroviral vectors, as described previously (13), and were generously donated by Emily J. Platt. 

^bHeterokaryons were formed by coculturing H9 cells with HeLa-tc-gp160 cells as described in the legend to Fig. 1. Virus harvested at 24, 48, and 72 h after coculturing of cells was used to infect HeLa-CD4 cells. 

^cHeLa-CD4 cells were infected with wild-type or vif-deleted HIV gpt virus produced from heterokaryons. Infected cells were selected with medium containing mycophenolic acid, and selected colonies were counted 15 to 21 days later.