Table 3.
Effect of combined membrane-bound complement regulatory protein (mCRP) blockade on complement susceptibility of OAW42, OAW42-Tax and the revertant OAW42-Tax-rev cells.
| Cell type | Adjusted lysis (%)* | Significance |
|---|---|---|
| OAW42 | 100 ± 1·3 | |
| OAW42 + Mg2+ EGTA | 1·4 ± 5·3 | P < 0·001 (versus OAW42) |
| OAW42 + α-mCRP* | 105·6 ± 2·9 | P < 0·05 (versus OAW42) |
| OAW42-Tax | 17 ± 1·5 | P < 0·001 (versus OAW42) |
| OAW42-Tax + Mg2+ EGTA | −3·8 ± 1·3 | P < 0·001 (versus OAW42-Tax) |
| OAW42-Tax + α-mCRP | 117·9 ± 4·2 | P < 0·001 (versus OAW42-Tax) |
| P < 0·05 (versus OAW42+αmCRP) | ||
| OAW42-Tax-rev | 32·4 ± 3·2 | P < 0·01 (versus OAW42-Tax) |
| P < 0·001 (versus OAW42) | ||
| OAW42-Tax-rev + Mg2+ EGTA | 1·2 ± 0·7 | P < 0·001 (versus OAW42-Tax-rev) |
| OAW42-Tax-rev + α-mCRP | 114 ± 2·5 | P < 0·001 (versus OAW42-Tax-rev) |
| P < 0·05 (versus OAW42+αmCRP) |
OAW42 cells and their variants OAW42-Tax and OAW42-Tax-rev were preincubated with a combination of non-complement-activating monoclonal antibodies against CD59, CD55 and CD46 to block mCRP. Results are presented as mean percentage adjusted lysis ± standard deviation (as triplicates). Mg2+-ethylene glycol tetraacetic acid (EGTA) was added in one set of experiments to test for classical versus alternative complement activation. Specific complement-induced lysis of parental OAW42 (85·3%) was set as 100% and the specific lysis rates of the MDR-variants and cells after mCRP blockade are presented relative to the parental cells.