Fig. 2.

C3 and C5 binding via the lectin (E-M-MBL) and classical (EA) pathways, respectively, in a constant amount of C8D serum using cells sensitized with varying amounts of mannan and antibody in order to yield comparably high (a) and low (b) binding of C4; the darkened bars refere to C8D serum which was depleted of factor D in order to exclude alternative pathway amplification. Much less C3 and C5 were bound via the lectin pathway at both high and low levels of C4 deposition; inhibition of alternative pathway amplification reduced the level of C3 and C5 binding via the lectin pathway, as well as via the classical pathway at the lower level of C4 deposition. Standard errors of the mean are indicated by error bars.