Shiga toxin binding to platelets as determined by flow cytometry
| Stimulant . | Mean intensity* . | P . | Inhibition after preincubation with anti-Stx1 (%) . |
|---|---|---|---|
| Unstimulated | 2.17 | ||
| Stx1 10 pg/mL | 84.84 | < .05 | nt |
| Stx1 100 pg/mL | 192.32 | < .05 | nt |
| Stx1 1 ng/mL | 184.97 | < .05 | nt |
| Stx1 10 ng/mL | 317.23 | < .05 | nt |
| Unstimulated | 0 | ||
| Stx1B 10 pg/mL | 392.54 | < .05 | nt |
| Stx1B 100 pg/mL | 385.23 | < .05 | 100 |
| Stx1B 1 ng/mL | 423.85 | < .05 | 57 |
| Stx1B 10 ng/mL | 547.47 | < .05 | 72 |
| Stimulant . | Mean intensity* . | P . | Inhibition after preincubation with anti-Stx1 (%) . |
|---|---|---|---|
| Unstimulated | 2.17 | ||
| Stx1 10 pg/mL | 84.84 | < .05 | nt |
| Stx1 100 pg/mL | 192.32 | < .05 | nt |
| Stx1 1 ng/mL | 184.97 | < .05 | nt |
| Stx1 10 ng/mL | 317.23 | < .05 | nt |
| Unstimulated | 0 | ||
| Stx1B 10 pg/mL | 392.54 | < .05 | nt |
| Stx1B 100 pg/mL | 385.23 | < .05 | 100 |
| Stx1B 1 ng/mL | 423.85 | < .05 | 57 |
| Stx1B 10 ng/mL | 547.47 | < .05 | 72 |
Stx indicates Shiga toxin; nt, not tested; IgG, immunoglobulin G; FITC, fluorescein isothiocyanate.
Numbers represent the median of mean fluorescence intensity of the entire population after subtraction of the background fluorescence (mouse IgG and antimouse-FITC). Results from 5 experiments for Stx1 and 4 experiments for Stx1B are shown. Stx1/BStx1 bound to 5% to 21% of platelets in the different experiments. Inhibition experiments with anti-Stx1 antibody were carried out twice for Stx1B. Pvalues compare the median for each stimulant with the unstimulated platelets.