Which of the following is an opsonin?
Correct Answer: C3b
Description: Ans. b. C3bRef: Robbins and Cotran Pathologic Basis of Disease 9th Ed; Page No-132Complement: System of hepatically synthesized plasma proteins that play a role in innate immunity and inflammation. Membrane attack complex (MAC) defends against gram [?] bacteria.Function of the ComplementC3b--opsonization.C3a, C4a, C5a--anaphylaxis.C5a--neutrophil chemotaxis.C5b-9--cytolysis by MACMnemonicC3b binds bacteriaOpsonins--C3b and IgG are the two 1deg opsonins in bacterial defense; enhance phagocytosis. C3b also helps clear immune complexes.Inhibitors--decay-accelerating factor (DAF, also known as CD55) and C1 esterase inhibitor help prevent complement activation on self-cells (e.g. RBCs).
Category:
Pathology
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now