2nd line of defense: complement basic properties Flashcards Preview

immunology 1139 > 2nd line of defense: complement basic properties > Flashcards

Flashcards in 2nd line of defense: complement basic properties Deck (19):
1

what is the complement cascade system

enzyme cascade system consist of 30+ serum/plasma proteins involved in immune and inflammatory response

2

difference of plasma and serum

plasma- separated from unclotted whole blood. serum separated from clotted blood no fibrinogen

3

where are complements produced

liver

4

complements exist as

inactive forms (some are protease enzymes called zymogens). C3 is inactive C3a and C3b is active

5

how does complement work as acute phase protein/reactant

increase of APR/APP can be detected in blood/serum during acute phase of inflammation. eg C reactive protein

6

define biological amplification

small initiating stimulus triggers a rapid and vigorous response to an infection

7

purpose of enzymatic rxns in regards to complement

activations sequential complement system. each rxn cleaves inactive from to 2 active form

8

which fragment diffuses away

smaller fragment "a" diffuses away. bigger "b" will remain close to site of activation

9

consequences of complement activation

inflammation, chemotaxis, opsonization, MAC

10

Describe how anaphylatoxins cause inflammation

anaphylatoxins (C3a and C5a) bind to receptors (C3aR C5aR) on mast cells & basophils leading to degranulation w/ release of vasoactive mediators like histamine

11

chemotaxis

chemotactic agents C3a and C5a diffuse away creates [gradient] attracting WBC like phagocytes

12

opsonization

opsonin C3b coats surface of microbes rendering them easily capture by phagocytes

13

Membrane attack complex

C5-C9 join to from MAC can puncture microbe's membrane leading to lysis

14

how is the alternate pathway initiated

C3 binds to surface of microorganism

15

how is classical pathway activated

C1 binding to receptor on antibody IgG/ IgM that is complexed with specific antigen (antigen-antibody or immune complex)

16

what is the most direct and simplest pathway

alternate

17

how is the lectin pathway initiated

C4 binding to mannose-binding protein that is attach to microbial surface

18

what is mannose

type of sugar found on microbe surfaces

19

example of APR/APP acute phase protein/reactant

bacteria induce macrophage to make IL-6 which acts on hepatocytes to induce synthesis of acute phase proteins. CRP binds phosphoryline cholie on surface actin as opsonin and complement activator