TABLE 3.
Fraction of Salmonella bacteria inside J774A.1 cells in which the SOS response was induced at 4 h and 24 h postinfection
| Treatment | 4 h postinfection |
24 h postinfection |
||
|---|---|---|---|---|
| % bacteriaa | % SOS+ cellsb | % bacteria | % SOS+ cells | |
| DMEM | 66.7 ± 4.4 | 1.4 ± 1.3 | 74.3 ± 1.7 | < 0.01 |
| 0.6% DMSO | 80.2 ± 3.5 | 0.3 ± 0.2 | 57.8 ± 08 | < 0.01 |
| 50 μM wrwycr | 57.1 ± 5.8 | 0.3 ± 0.1 | 45.2 ± 10.2 | 0.4 ± 0.2 |
| 1.2% DMSO | 76.1 ± 4.0 | 0.1 ± 0 | 57.1 ± 13.3 | 0.03 ± 0.1 |
| 100 μM wrwycr | 19.0 ± 1.7 | 1.3 ± 0.6 | 2.8 ± 0.5 | 16.5 ± 4.8 |
| 1.8% DMSO | 82.5 ± 3.7 | 0.1 ± 0.1 | 54.2 ± 9.8 | < 0.01 |
| 150 μM wrwycr | 3.0 ± 0.9 | 8.5 ± 3.1 | 1.9 ± 0.2 | 28.4 ± 5.2 |
% bacteria, the fraction of Salmonella bacteria, determined by reactivity with LPS antibody, among the number of particles released by lysis of J774A.1 cells that fit the forward-scatter versus side-scatter parameters characteristic of bacterial cells. The other particles may be mitochondria and/or other nonbacterial particles.
% SOS+ cells, the fraction of fluorescein-positive Salmonella bacteria (LPS-positive particles). All the differences between the percentage of SOS response-positive cells in 1.2% DMSO versus the percentage obtained after treatment with 100 μM peptide and in 1.8% DMSO versus the percentage obtained after treatment with 150 μM peptide at either 4 h or 24 h are significant (P values of 0.0022 in all cases, in Wilcoxon exact one-tailed t tests).