TABLE 1.

Classification and characterization of virus stocks of HIV-1 group M and group O isolates used in this study

Virus isolateGroupSubtypeCoreceptor usageap24 CA level (ng/ml)bTCID50 (IU/ml)cInfectivity (IU/ng of p24 CA)d
NL4-3MBX435,14468,0801.94
2005MBX43,8271,5400.40
2044MBX41,7431,7781.02
ELIMDX44,5701780.04
JR-FLMBR54,31541,2489.56
Ba-LMBR59,400316,22833.64
IN22MCR51,4482,6101.80
RU570MGR54425621.27
RW9MAR54401,0002.27
D117MBR52,8701,7780.62
2901OX4551,54028.00
1639OR55656210.04
2549OR51175624.80
6778OR54051780.44
8913OR5581783.07
13127OR51933,16216.38
13740OR51245624.53
9435OR5500NDND
  • a Coreceptor usage was determined as described in Materials and Methods, and representative data are shown in Fig. 1.

  • b CA, capsid protein.

  • c The infectious titer was determined on a pool of phytohemagglutinin/IL-2-activated PBMCs from six donors by end-point limiting dilution 5 days after inoculation as reported previously (32). ND, not determined; IU, infectious units.

  • d The arithmetic mean ± standard error of the mean of relative infectivity (IU/ng of p24 CA) was 5.26 ± 3.27 for group M isolates and 9.6 ± 3.65 for group O isolates. ND, not determined; IU, infectious units.