Immunity

Question 1

IL-1

Answer 1

Activates NF𝜅B/AP1 (transcription factors)

Proinflammatory, endogenous pyrogen

Question 2

IL-6

Answer 2

Pro-inflammatory, acute phase protein response, endogenous pyrogen

Question 3

IL-12

Answer 3

Stimulates T/NK cells

Increases IFNɣ/TNFα production, cytotoxicity and TH1 response

Question 4

TNFα

Answer 4

Activates NF𝜅B/AP1 (transcription factors)
Acute phase protein response, endogenous pyrogen
Involved in spetic shock

Question 5

CXCL8 (IL-8)

Answer 5

Chemokine: attracts neutrophils/other cells

Question 6

Complement activation

Answer 6

Alternative: spontaneous - iC3Bb convertase
Lectin: MBL/MASP-1/2, MBL binds mannose, C4b2a formed by MASP-2 cleavage
Classical: C1 (C1q/r/s), C1q binds Fc/CRP, C4b2a formed by C1s cleavage

Question 7

C3a/C5a

Answer 7

Anaphylatoxins: stimulate mast cell degranulation

Question 8

C3b/C4b/C5b

Answer 8

Opsins: enhance phagocytosis

Question 9

MAC

Answer 9

C3bBb + C3b → (C3b)(C3b)Bb cleaves C5 → C5b
C5b complexes with C6, C7, C8 which recruits C9 monomers to form MAC
MAC and perforin similar molecules
C3b opsonisation more important (except in some infections eg gonorrhoea and Neisseria meningitis)

Question 10

Properdin

Answer 10

Stabilises C3bBb on microbial surfaces

Question 11

Factor H

Answer 11

Binds C3b, recruits factor I which cleaves into iC3b

Question 12

Decay accelerating factor

Answer 12

Causes Bb to dissociate from C3bBb

Question 13

Membrane cofactor protein

Answer 13

Causes Bb to dissociate from C3bBb and recruits factor I

Question 14

CD59

Answer 14

Binds assembling MAC and prevents C9 recruitment

Question 15

MHC binding pocket

Answer 15

Class I: closed ends 8-9 a.a.

Class II: open ends 13-25 a.a.

Question 16

TAP

Answer 16

Peptide pump found in MHC locus (allows co-regulation) which pumps peptides into the ER for MHC class I loading

Question 17

Invariant chain

Answer 17

Binds MHC class II in ER to prevent self-peptides binding, cleaved in endosome to CLIP before being removed completely

Question 18

CD40

Answer 18

Crosslinking stimulates isotype switching and B-cell activation without co-stimulation (and promotes survival)

Question 19

Co-stimulation

Answer 19

CD40L (T-cell) - CD40 (APC)
CD28 (T-cell) - B7 (APC)
Results in IL-2 secretion: autocrine proliferative signal

Question 20

TH1-response

Answer 20

Stimulated and produce IFNɣ/IL-12 (IL-12 secreted by macrophages)
Inhibited by IL-4 (macrophages by IL-10)
Proinflammatory, intracellular infections
Cellular response (macrophage activation etc)

Question 21

TH2-response

Answer 21

Stimulated by IL-4 (from mast cells)
Production of IL-10 (inhibits macrophages), IL-4, 5, 13
Promotes humoral response and repair
Defence against helminths

Question 22

TH17-response

Answer 22

Enhanced neutrophils, IL-17 (also activate fibroblasts/epithelial cells to secrete chemokines)