Figure 1.

The complement cascade, factor H (encoded by CFH), and its interactions with N. meningitidis factor H binding protein (fHBP). The milieux shown here are the host endothelial cells, the interstitium, and invading N. meningitidis cells. Factor H normally binds to glycosaminoglycan sugars on host cells. This same region in Factor H is bound by the N. meningitidis through factor H binding protein (fHBP). There is significant diversity in fHBP, which is more variable in N. meningitidis serogroup B than in other serogroups. The serum concentration of CFH also varies with CFH genotype. Adapted from Tan et al. [66].