Mannan-binding lectin activates C3 and the alternative complement pathway without involvement of C2
J. Clin. Invest. Barbro Selander, et al. 116:1425 doi:10.1172/JCI25982 [Go to this article.]

Figure 6
Effect of serum dilution on C3 deposition induced by CO antigen (1,000 ng/well) in C2D:21 serum (combined C2 and MBL deficiency). The serum was reconstituted with MBL (2 mg/l) and C2 (6.5 mg/l) as indicated. PNHS was used as a control. MBL-dependent C2 bypass activation was abolished in 5–10% serum. By contrast, these serum concentrations appeared to be optimal for lectin pathway activation mediated through C4b2a. C3 incubations with serum were carried out at 37°C for 30 minutes. The experiment was performed in duplicate and was repeated once with similar results.