Fig. 5.

Measurement of C7 in the human umbilical vein endothelial cell (HUVEC) supernatant as free molecule or as a component of terminal complement complex (TCC). The cells were cultured in 15% C7-deficient human serum and samples were harvested daily for the assessment of the level of C7 (a) and of TCC (b). The lower curve of (b) (Δ) represents the TCC assembled spontaneously in the medium containing C7-deficient serum. The upper curve of (b) (□) represents the TCC formed following yeast cell wall treatment of medium containing further 20% C7-deficient serum to a final concentration of 35%. The results of TCC levels are expressed as equivalent amount of C7 used to set up a standard curve of TCC formed in the activated mixture of C7-deficient serum and increasing amounts of purified C7. Values are the mean ± s.d. for triplicate determinations of three cell cultures.