Table 1.
Effect of heat treatment or the presence of polymyxin B on cytokine secretion by PMA-differentiated U937 macrophages stimulated with the recombinant SspA (33 μg/ml) of S. suis.
| Conditions | Amount secreted (pg/ml) | ||
|---|---|---|---|
| CCL5 | IL-6 | CXCL8 | |
| Control (no stimulation) | 2081 ± 14 | 100 ± 1 | 3170 ± 9 |
| Recombinant SspA of S. suis | 2370 ± 61* | 1922 ± 31* | 108557 ± 620* |
| Heat-inactivated recombinant SspA of S. suis | 72409 ± 848* | 2111 ± 71* | 102287 ± 1062* |
| Recombinant SspA of S. suis + polymyxin B | 2081 ± 32 | 2099 ± 254* | 107446 ± 590* |
The data are the means ± SD of triplicate assays for three separate experiments. Asterisks indicate a significant difference in comparison with the unstimulated control at P < 0.01.