TABLE 1.
Inhibition of human PBMC proliferation in response to rSPEA, rM5 protein, and PHA by S. pyogenes Manfredo unfractionated CEa
| CE (μg/ml) | Uptake of [3H]thymidine
(cpm)
|
||||
|---|---|---|---|---|---|
| 3-day assay
|
7-day assay
|
||||
| Cells only | PHA (1.0 μg/ml) | rSPEA (1 nM) | Cells only | rM5 (5.0 μg/ml) | |
| 0 | 54 ± 2 | 4,575 ± 413 | 1,543 ± 6 | 160 ± 13 | 606 ± 63 |
| 0.04 | 102 ± 10 | 4,356 ± 605 | 1,397 ± 56 | 283 ± 113 | 799 ± 189 |
| 0.2 | 155 ± 22 | 4,251 ± 309 | 996 ± 178 | 393 ± 62 | 758 ± 75 |
| 0.5b | 66 ± 30 | 1,811 ± 140 | 195 ± 25 | 36 ± 4 | 46 ± 10 |
| 1.0b | 31 ± 3 | 933 ± 80 | 56 ± 4 | 32 ± 6 | 42 ± 5 |
| 5.0b | 12 ± 2 | 26 ± 5 | 21 ± 1 | 20 ± 3 | 29 ± 2 |
a
Human PBMC (2 × 106/ml) were incubated in 96-well plates with CE at a range of concentrations and with either rSPEA (3 days), PHA (3 days), or rM5 (7 days) prior to pulsing with tritiated thymidine for the final 6 h of culture. Results show mean values ± SEM for triplicate cultures and are representative of data obtained from two separate experiments.
b
Proliferation of human PBMC was significantly inhibited (P < 0.004) by CE at final concentrations of 0.5 μg/ml or higher.