2 Hour Surprise Complement Lecture

Question 1

Immunization

Answer 1

Ag stimulus that stimulus specific adaptive immune response that can be recalled during subsequent infections
Passive - Ab/antiserum only
Active - intro Ag that induces adaptive immune response

Question 2

Herd immunity

Answer 2

Immunity acquired when a critical number of individuals in a population are vaccinated

Question 3

Considerations for immunization schedule

Answer 3

Timing of exposure
Immunological maturity of child
Passively transferred Ab that may interfere with immune response of vaccine
Interference

Question 4

Passively transferred maternal IgG is completely degraded

Answer 4

At 9 months of age

Question 5

Criteria for effective vaccine (only indicated item)

Answer 5

Must induce protective T cells
Some pathogens, particularly intracellular, are more effectively dealt with by cell-mediated responses
Also need T cells to activate B cells for Ab production

Question 6

Inactivated vaccines contain

Answer 6

Killed/ inactivated viruses
Subunits or components
Toxoid
Conjugated Ag

Question 7

Adjuvants

Answer 7

Increase vaccine efficacy
Bacterial components or media that prolongs exposure or induces mild inflammation to attract phagocytes (increases chance that Ag will be picked up and presented)

Question 8

Conjugate vaccines

Answer 8

Capsular polysaccharides from pathogenic bacteria elicit a t independent response
Must conjugate the vaccines by linking to a polysaccharide to Ag or toxoid to form an immunogen (t-dependent Ag)

HiB vaccine

Question 9

Immunological tolerance

Answer 9

Unresponsiveness of adaptive immune system to Ag as a result of inactivation or death of Ag-specific lymphocytes, induced by exposure to the Ag

Question 10

Factors that promote immune tolerance

Answer 10

Soluble, aggregate free, simple small molecules
Improper processing 
Oral/IV presentation 
Age (too young or too old) 
Dose (too large or small)

Question 11

Characteristics that promote adaptive immune response

Answer 11

Large, aggregated complex molecules 
Proper processing 
Subcutaneous or IM exposure 
Intermediate dose 
not young af or old af

Question 12

Functions of complement

Answer 12

Triggering, amplification of inflammation 
Attraction of phagocytes by chemotaxis 
Clearance of immune complexes 
Cellular activation 
Direct microbial killing
Development of humoral response

Question 13

Classical pathway is activated by

Answer 13

Ab-Ag complex stimulates C1 binding

Either IgG or IgM (must bind multiple globular domains of C1q in order to activate)

Question 14

Alternative pathway activated by

Answer 14

Spontaneous lysis of C3

Question 15

Lectin pathway initiated by

Answer 15

MBL binding lectin and recruiting MASP1 + MASP2

Question 16

C1qrs can be inhibited by

Answer 16

C1 inhibitor

Binds C1r and C1s to prevent cleave of C4 and C2

Question 17

C3 convertase classical pathway consists of

Answer 17

C4b2a

Question 18

C5 convertase classical pathway consists of

Answer 18

C4b2a3b

Question 19

Inserts into membrane and forms small pore

Answer 19

C4b67

Question 20

Recruits 10-16 copies of C9

Answer 20

C8

Question 21

Host cells protect themselves from spontaneous lysis of C3 by expressing high levels of what on their cell surface

Answer 21

Sialic acid

Question 22

Factor D

Answer 22

Cleaves factor B –> Bb and Ba

Question 23

Binds C3bBb and C3bBb3b and prevents increases half-life

Answer 23

Properdin

Question 24

Alternative C3 convertase

Answer 24

C3bBb

Question 25

Alternative C5 convertase

Answer 25

C3bBb3b

Question 26

Binds N-acetylglucosamine on bacterial cell wall to induce autocleavage of MASP1 and MASP2

Answer 26

Ficolin

Question 27

Deficiency resulting in: High degree of SLE from failure to clear circulatory immune complexes - deposits on endothelial cells and activates alternative complement, local inflammation

Answer 27

C2 deficiency

Question 28

Deficiencies in Factor H and Factor I mimic

Answer 28

C3 deficiencies - unregulated C3b generation exhausts C3 from serum

Question 29

Deficiency results in increased susceptibility to Neisseria gonorrhoeae and N. meningitidis

Answer 29

MAC deficiencies (C5-C9)

Question 30

Factor I

Answer 30

Cleaves C3b and C4b Cofactors: Factor H, MCP, C4BP, CR1 SERINE PROTEASE

Question 31

Factor H

Answer 31

Binds C3b and displaces Bb | Also serves as a cofactor for Factor I cleavage of C3b

Question 32

C4BP

Answer 32

C4 binding protein - binds C3b and displaces C2 | Cofactor for Factor I cleavage of C4b

Question 33

DAF functions in a similar capacity as what two RCAs?

Answer 33

``` Factor H (alternative pathway) C4BP (classical pathway) ```

Question 34

MCP

Answer 34

Also known as CD46 | Cofactor for Factor I cleavage of C3b and C4b

Question 35

DAF

Answer 35

Displaces C2b from C4b (classical) Displaces Bb from C3b (alternative) Aka inactivates the C3 convertases

Question 36

CD59

Answer 36

Blocks C9 binding and prevents formation of MAC

Question 37

Vibronectin

Answer 37

S protein - prevents C5b67 from penetrating (heh) membrane

Question 38

Hereditary Angioneurotic Edema

Answer 38

C1 inhibitor deficiency Swelling attacks from physical trauma/emotional stress Affects extremities, face, GI tract Treat with androgens (increase transcription of C1 inhibitors)

Question 39

Paroxysmal nocturnal hemoglobinuria

Answer 39

Deficient DAF Hemolytic disorder with spontaneous episodes of RBC lysis, leukocytes, platelets sensitive to complement Treat with EPO

Question 40

Type III Hypersensitivity

Answer 40

Little Ab and excess Ag will lead to small immune complexes that are not cleared from circulation because they do not fix complement --> local inflammation --> basophils degranulation, platelet aggregation --> increase vascular permeability --> complex deposition --> attract neutrophils who further mess it up ==> increased Bp and vascular turbulence

Question 41

Biological functions of complement

Answer 41

``` Opsonization (C3b, and a little C4b) Waste management (C3b binds CR1 of RBCs to transport Immune complexes to spleen/liver) Cell lysis (mac) Inflammatory mediators (anaphylatoxins C3a, C5a, C5b67) ```

Question 42

Prokinin

Answer 42

Also known as C2b - cleaved by plasmin to yield kinin --> edema

Question 43

Epstein Barr virus abuses complement to gain entry into cells by

Answer 43

Using CR2 as a receptor for attachment

Question 44

Measles utilizes the complement system to infect cells by

Answer 44

Using MCP (CD46) as a receptor

Question 45

West Nile hijacks complement machinery by

Answer 45

Coating viral particles in C3b to gain entry into cells by CR3

Question 46

Neisseria meningitidis escapes complement degradation by

Answer 46

Expressing protein on its cell surface that block the formation of convertases

Question 47

CH50 assay tests for

Answer 47

Test ability of patients blood to perform Complement mediated hemolysis

Question 48

Classical deficiency

Answer 48

Increases risk of developing immune complex diseases like SLE

Question 49

MBL deficiency

Answer 49

Increases risk of infection by yeast sacchromyces cerevisiae and encapsulated bacteria

Question 50

Alternative pathway deficiency

Answer 50

Decreases opsonization activity and increases risk of infection by encapsulated bacteria

Question 51

C3 deficiency

Answer 51

``` Leads to Defective opsonization Defective leukocyte chemotaxis Decreased bactericidal killing activity (no MAC) Also indicated in immune complex disease ```

Question 52

MAC deficiency

Answer 52

Increased risk of infection to N. meningitidis