Figure 3
C3b deposition and complement-mediated cytotoxicity. A: Deposition of opsonizing C3 split products on DAF- and/or MCP-deficient tumour cells (measured as common C3b moiety). Tumor cells were transfected with negative shRNA, MCP shRNA, DAF shRNA and MCP shRNA+ DAF shRNA respectively, as indicated in the diagram. Following complement activation by polyclonal tumor-specific antibodies, deposited C3b molecules were quantified by flow cytometry. Data are shown from one representative experiment (of three). Negative shRNA, MCP shRNA, DAF shRNA versus MCP shRNA+ DAF shRNA. **p < 0.01; MCP shRNA, DAF shRNA versus negative shRNA. *p < 0.05, respectively. B: Complement-dependent cytolysis of DAF- and MCP-deficient ME180 cells. Tumor cells were transfected with negative shRNA, MCP shRNA, DAF shRNA and MCP shRNA+ DAF shRNA respectively, as indicated in the diagram. 72 h later, complement-dependent cytolysis of ME180 cells was measured. Data are presented as means ± SD of triplicates of one representative experiment (of three). DAF shRNA, MCP shRNA, MCP shRNA+ DAF shRNA versus negative shRNA. **p < 0.01; ***p < 0.001; MCP shRNA, DAF shRNA versus MCP shRNA+ DAF shRNA.*p < 0.05, respectively.