TABLE 4.

Coreceptor usage by primary HIV-2 isolates tested in GHOST(3) cells coexpressing CD4 and CCR5, CXCR4, or the orphan receptor Bonzo or BOB

Virus isolate	HIV-2 antigen production (Ag) and GFP activation (F) in GHOST(3) cells coexpressing CD4 and the following HIV coreceptora:
	None		CCR5		CXCR4		Bonzo		BOB
	Ag	F	Ag	F	Ag	F	Ag	F	Ag	F
1010	0	+	0.5	++	2.2	+++	0.2	++	0.4	++
1654	0	−	1.3	+++	0	−	0	+	0.2	++
1682	0	−	0	+++	0	−	0	+	0	+
1808	0	−	1.2	+++	0	−	0	+	0	+
1812	0	−	1.3	+++	0	−	0	+	0.2	++
2297	0	+	1.4	+++	0	+	0	+	2.2	+++
2298	0	−	1.2	+++	0	−	0	+	0	+
2300	0	−	1.2	+++	0	−	0	+	0	++
6669	0	+	0	+	1.2	+++	0	+	0	+
1653	0	−	0.2	+++	0	−	0	−	0	+
IIIBb	0c	+	0c	+	>2.7c	+++	0	+	0	+

^aInfection assays were performed by cell-free virus infection with 1,000 to 2,000 TCID₅₀ of each HIV-2 isolate. Experiments were carried out twice. Ag, cell culture supernatants were harvested at day 8 postinfection and monitored for HIV-2 antigen with an in-house capture ELISA; values represent the mean optical density at 490 nm from two independent experiments (0 indicates an optical density of <0.2). F, HIV-induced GFP activation in GHOST(3) cell cultures was detected by observing the cultures with a fluorescence microscope. The percentage of cells showing fluorescence was estimated at day 8 postinfection: +++, >30%; ++, 5 to 30%; +, 1 to 5%; −, 0%. 

^bPrototype TCLA laboratory HIV-1 strain. 

^cp24 production measured with an in-house HIV-1 p24 capture ELISA.