Fig. 4.

Influence of the classical and the alternative pathway on deposition of C3 on apoptotic Jurkat cells. Purified C1q (a) or factor D (b) was added to a mannose binding lectin (MBL)-deficient serum depleted of C1q and factor D. Cells were incubated with the C1q- and D-depleted serum at serum concentration of 25%. Deposition of C3 is given as the percentage of positive cells and as mean fluorescence intensity (MFI) using antibodies against C3d. (a) Deposition of C3 after addition of C1q at 0·1% (0·7 mg/l) to 100% (70 mg/l); (b) deposition of C3 after addition of factor D at 0·1% (0·001 mg/l) to 100% of normal (1 mg/l). Mean values and the standard deviation of three experiments are shown. Early apoptotic and late apoptotic cells are given as early AC and late AC respectively.