Inhibition of NK activity by the addition of platelets
| The inhibitory capacity of platelets from mice of different strains and the influence of aggregation inhibitors hirudin (1 unit/ml), heparin (1 unit/ml), apyrase (5 units/ml), anti-P-selectin MAb (10 μg/ml), 2-h platelet supernatant, or 2-h platelet + YAC1 supernatant were determined in a 4-h 51Cr-release NK assay using C3H/HeN spleen cells as source of NK cells. The data given were obtained with an E:T ratio of 100:1 and in the presence of 10,000 platelets per YAC1 tumor cell. Specific lysis without the addition of platelets or inhibitors was 36.6 ± 1.2% in A, 46.5 ± 1.1% in B, and 11.6 ± 0.4 in C. | ||
|---|---|---|
| Platelet donor mouse strain | Added substance | Inhibition of specific lysis % |
| A | ||
| − | − | 0 |
| C3H/HeN | − | 54.7 ± 4.5 |
| C57BI/6 | − | 56.1 ± 1.1 |
| C57BI/6/SVJ129 | − | 53.8 ± 2.5 |
| NMRI | − | 64.2 ± 0.8 |
| β2-Microglobulin−/− | − | 46.6 ± 2.4 |
| B | ||
| C3H/HeN | Hirudin | 0.5 ± 4.4 |
| C3H/HeN | Heparin | 41.3 ± 3.2 |
| C3H/HeN | Apyrase | 38.1 ± 4.3 |
| C3H/HeN | Anti-P-selectin | 36.0 ± 4.5 |
| C3H/HeN | Rat IgG | 65.8 ± 7.0 |
| C | ||
| − | − | 0 |
| C3H/HeN | − | 77.4 ± 4.6 |
| − | Platelet supernatant | 32.8 ± 5.2 |
| − | Platelet + YAC1 Supernatant | 30.4 ± 4.8 |