TABLE 1.
Classification and characterization of virus stocks of HIV-1 group M and group O isolates used in this study
| Virus isolate | Group | Subtype | Coreceptor usagea | p24 CA level (ng/ml)b | TCID50 (IU/ml)c | Infectivity (IU/ng of p24 CA)d |
|---|---|---|---|---|---|---|
| NL4-3 | M | B | X4 | 35,144 | 68,080 | 1.94 |
| 2005 | M | B | X4 | 3,827 | 1,540 | 0.40 |
| 2044 | M | B | X4 | 1,743 | 1,778 | 1.02 |
| ELI | M | D | X4 | 4,570 | 178 | 0.04 |
| JR-FL | M | B | R5 | 4,315 | 41,248 | 9.56 |
| Ba-L | M | B | R5 | 9,400 | 316,228 | 33.64 |
| IN22 | M | C | R5 | 1,448 | 2,610 | 1.80 |
| RU570 | M | G | R5 | 442 | 562 | 1.27 |
| RW9 | M | A | R5 | 440 | 1,000 | 2.27 |
| D117 | M | B | R5 | 2,870 | 1,778 | 0.62 |
| 2901 | O | X4 | 55 | 1,540 | 28.00 | |
| 1639 | O | R5 | 56 | 562 | 10.04 | |
| 2549 | O | R5 | 117 | 562 | 4.80 | |
| 6778 | O | R5 | 405 | 178 | 0.44 | |
| 8913 | O | R5 | 58 | 178 | 3.07 | |
| 13127 | O | R5 | 193 | 3,162 | 16.38 | |
| 13740 | O | R5 | 124 | 562 | 4.53 | |
| 9435 | O | R5 | 500 | ND | ND |
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.