TABLE 1.
Protease activities in peritoneal exudates
Cell-free peritoneal exudates collected at indicated time points after intraperitoneal infection with T. gondii and from noninfected animals (n = 3) were assayed for chymotrypsin-, trypsin-, and CPA-like activities as described under “Experimental Procedures.”
| Time point/Mice | Chymotrypsin-like activity (substrate S-2586)a | Trypsin-like activity (substrate S-2288)a | Carboxypeptidase A-like activity (substrate M-2245)a |
|---|---|---|---|
| Noninfected | |||
| SG+/+ | 0.2 ± 0.1 | 13.6 ± 3.2 | ND |
| SG−/− | NDb | 1.0 ± 0.1 | ND |
| 12 h | |||
| SG+/+ | 0.8 ± 0.1 | 13.8 ± 0.5 | ND |
| SG−/− | 0.7 ± 0.5 | 21.2 ± 1.6 | ND |
| 24 h | |||
| SG+/+ | 0.4 ± 0.1 | 4.9 ± 1.1 | ND |
| SG−/− | 0.7 ± 0.2 | 15.6 ± 4.9 | ND |
| 48 h | |||
| SG+/+ | 0.9 ± 0.4 | 26.4 ± 7.1 | −3.4 ± 1.7 |
| SG−/− | 1.2 ± 0.4 | 31.0 ± 1.5 | −2.9 ± 0.8 |
| Day 8 | |||
| SG+/+ | 4.4 ± 0.9 | 32.7 ± 0.70 | −2.7 ± 0.8 |
| SG−/− | 7.6 ± 3.8 | 31.3 ± 0.30 | −5.0 ± 0.5 |
a Activities are expressed as mean change in absorbance (Δmilli OD/(min × ml of cell-free exudates) ± S.E.). Note that hydrolysis of the CPA substrate results in decreased absorbance.
b ND, not detected.