TABLE 4.

Epitope specificities of serum antibodies determined by MAb binding competition

Group	Binding to JRFL gp120a	Neutralization of JRFLb		Competition titerc
				CD4BS			Glycan (2G12)	V3		CD4i (X5/sCD4)	Cluster I (7B2)
		Standard	After CD4	b6	15e	b12		LE311	LE311/sCD4
SF162gp140	5,000	<100	6,000	<100	<100	<100	<100	125	250	<100	<100
ΔV2gp140	4,000	<100	3,000	100	225	<100	<100	100	500	<100	<100
ΔV3gp140	10,000	<100	120	<100	100	<100	<100	100	500	150	<100
ΔV2ΔV3gp140	17,000	<100	<100	100	125	<100	<100	<100	150	<100	<100
SHIVSF162P4d	150,000	250	>30,000	300,000	500	<100	500	17,000	70,000	24,000	>25,000
Prebleede	<1,000	<100	<100	<100	<100	<100	<100	<100	<100	<100	<100
Selff				0.01	0.08	0.02	0.2	0.008	0.008	0.005	0.005

^aValues indicate the reciprocal serum dilution resulting in half-maximal binding.

^bValues indicate reciprocal serum dilution resulting in 50% neutralization in the absence of sCD4 (standard) or following preincubation of viruses with sCD4 (after CD4).

^cValues indicate the reciprocal serum dilution at which MAb-mediated virus capture was competed 50%.

^dFor SHIV_SF162P4, the sera tested were collected 643 days postinfection.

^eFor prebleed, preimmunization sera pooled from all animals were included in all groups.

^fSelf denotes competition with the same MAb used for capture recorded in μg/ml.