Mannose Binding Lectins (MBL) and Ficolins Are the Two Classes

Multiple Choice

Mannose binding lectins (MBL) and ficolins are the two classes of proteins that can initiate the lectin pathway of complement activation. These proteins are selective for activating complement on the surfaces of microbial pathogens rather than host cells because:

A) Their higher-order oligomeric structure can be assembled only after the monomers first bind to pathogen membranes.
B) They only recruit MASP (MBL-associated serine proteases) proteins when bound to pathogen surfaces and not when bound to host cells.
C) They only undergo the conformational change needed to activate MASP proteins when bound to a pathogen and not when bound to a host cell.
D) They only bind to carbohydrate side chains and oligosaccharide modifications found on pathogen surfaces but not on host cell membranes.
E) The activated MASP proteins are rapidly inactivated by hydrolysis when present on the surface of a host cell.