Complement activation in the innate immune system can be initiated in the absence of antibody.Which of the following molecular components of the complement system is involved in initiation of antibody-independent complement activation?
A)C1
B)C9
C)Mannose binding lectin
D)CR2
E)Mannose receptor

Question

Quizplus · Accepted Answer

Mannose-binding lectin (MBL)is a soluble serum component that is structurally similar to C1 of the classical complement pathway.MBL binds to mannan residues on microbial surfaces and triggers proteolytic cleavage and activation of downstream components of the complement system.C9 is not involved in initiation of complement activation but is part of the common final membrane attack complex (MAC)pathway.CR2 is a cell surface receptor for complement fragments.A mannose receptor is a cell surface receptor on phagocytes that binds mannan residues and promotes phagocytosis of microbes.

Complement Activation in the Innate Immune System Can Be Initiated