Complement Flashcards

Complement Fixation Pathways

Question	Answer	Article
What are the names of the different pathways of the complement cascade?	Classical Alternative Mannose-binding Lectin	Link to Answer Article
Which immunoglobulins can activate the classical pathway?	IgM IgG	Link to Answer Article
What are the components of the C1 complex	C1q C1r C1s	Link to Answer Article
Which two complexes bind to make the enzyme C3 convertase?	C2b C4b	Link to Answer Article
What initiates the membrane attack complex (MAC)?	C3b	Link to Answer Article
What functions do the Ca fragments have?	Chemotactic for neutrophils Induces acute inflammation Increases vascular permeability Causes mast cell and basophil degranulation	Link to Answer Article
What are efficient activators of the alternative pathway?	Gram-negative bacteria Yeasts Fungi	Link to Answer Article
What are the main functions of the alternative pathway?	To coat bacteria with iC3b To induce an acute inflammatory response	Link to Answer Article
What are lectins?	Proteins which bind carbohydrates	Link to Answer Article
What does MASP stand for?	Mannose-binding lectin associated proteases	Link to Answer Article

Question	Answer	Article
Which complement inhibitor exorts control over the classical pathway and how does it function?	Delay acclerating factor (DAF) Increases the degredation of C1 esterase	Link to Answer Article
What do factors I and H do?	Breaks down C3b Controls positive feedback by inhibiting C3b¯Bb Prevents the complement cascade from running to exhaustion every time it is activated	Link to Answer Article
Which complement inhibitor binds inflammatory immune complexes in the plasma, transporting them to the liver for phagocytosis?	Complement receptor 1 (CR1)	Link to Answer Article
What does CD59 do?	Prevents cell lysis and pore formation It is a protective mechanism for cells	Link to Answer Article

Question	Answer	Article
What are the stages of opsonisation?	The complement system deposits a shell of protein on the bacterial cell surface, e.g. complement fragments Complement fragments released are chemotactic for phagocytes iC3b acts as a target for phagocytosis Phagocytes bind with the complement fragments destroying the bacteria	Link to Answer Article
What role do complement fragments have to promote inflammation?	Smaller complement fragments attract granulocytes to the site of inflammation Smaller complement fragments stimulate the degranulation of granulocytes	Link to Answer Article
By which process can C5-C9 directly kill pathogens?	Cell lysis	Link to Answer Article