TABLE 1.
NO production and control of parasites during T-cell-mediated activation of TNFR-deficient PECsa
| Cells | Treatment | NO2 (μM) | Parasites/100 macrophages |
|---|---|---|---|
| TNFRp55p75−/− | Medium | <4 | 348 ± 29 |
| Anti-CD3 | 47 ± 1 | 42 ± 19 | |
| Anti-CD3 + XMG | 5 ± 1 | 331 ± 14 | |
| Anti-CD3 + l-NMMA | 5 ± 1 | 376 ± 2 | |
| Anti-CD3 + d-NMMA | 41 ± 1 | 16 ± 4 | |
| TNFRp55−/− | Medium | <4 | 215 ± 110 |
| Anti-CD3 | 47 ± 1 | 16 ± 1 | |
| Anti-CD3 + XMG | <4 | 465 ± 6 | |
| Anti-CD3 + l-NMMA | 6 ± 1 | 436 ± 19 | |
| Anti-CD3 + d-NMMA | 42 ± 1 | 15 ± 11 | |
| Wild type | Medium | <4 | 264 ± 10 |
| Anti-CD3 | 57 ± 1 | 26 ± 7 | |
| Anti-CD3 + XMG | <4 | 301 ± 19 | |
| Anti-CD3 + l-NMMA | 8 ± 1 | 292 ± 29 | |
| Anti-CD3 + d-NMMA | 53 ± 1 | 16 ± 4 |
a
Resident PECs were harvested, suspended at 106 macrophages/ml, and infected for 2 h with two amastigotes per macrophage in the presence of the anti-CD3 (5 μg/ml) and indicated blocking reagents. NO2 was quantitated from the supernatants at 72 h of culture by the Greiss reagent, and parasites per 100 macrophages was determined by counting differential stains of duplicate cultures (minimum of 400 macrophages/experimental group) 72 h postinfection. The data shown are the mean NO2 levels ±SE or the mean number of parasites per 100 macrophages ± SE from one experiment. The experiment was repeated, with similar results.