Chapter 6

Question 1

Only () is allowed to bind to MHC molecules.

Answer 1

Peptides

Question 2

T cells recognise () peptides but not conformational determinants of protein antigens.

Answer 2

Linear

Question 3

Define MHC restriction.

Answer 3

A single T cell can recognise a specific peptide displayed by only 1 of the large number of different MHC molecules that exist.

Question 4

() interaction is required for class II MHC & costimulators expression in APC.

Answer 4

CD40L-CD40

Question 5

Define priming.

Answer 5

DC presents antigen to naive T cell in initiation of T cell response into protein antigen.

Question 6

Which cell is the most effective APC for activating naive T cells in initiating T cell response?

Answer 6

Dendritic cells

Question 7

Why DC, macrophage & B lymphocyte are called professional antigen presenting cells?

Answer 7

Express class II MHC capable of activating CD4+ T cells

Question 8

Name the cytokines involved in positive feedback loop of

1) CD4+ T cell
2) other T cell

Answer 8

1) CD40L (CD154)

2) IFN-gamma

Question 9

Class I MHC is expressed in ().

Answer 9

All nucleated cells

Question 10

Name 2 cell types that express class II MHC & may present antigens to T cells other than the 3 APC.

Answer 10

Endothelial cells

Thymic epithelial cells

Question 11

() is a major determinant of graft acceptance & rejection.

Answer 11

HLA alleles encoding HLA antigen

Question 12

Which gene is specific for graft rejection?

Answer 12

Immune response (Ir) genes

Question 13

MHC genes are the most polymorphic genes present in any mammalian genome. True or false?

Answer 13

True

Question 14

Name the entities of class I & II MHC genes.

Answer 14

Class I MHC (HLA-A, HLA-B & HLA-C)

Class II MHC (HLA-DP, HLA-DQ, HLA-DR)

Question 15

() is the master regulator of class II MHC gene expression in which its mutation leads to ().

Answer 15

Class II transcription activator (CIITA)

Bare lymphocyte syndrome

Question 16

List 7 molecules that class II genes encode for.

Answer 16

DP, DQ, DR
DM
Proteasome 
TAP1 & TAP2
DOA & DOB

Question 17

List 3 molecules encoded by class III region.

Answer 17

Factor B
TNF-alpha
Complement C4a, C4b & C2

Question 18

List 6 molecules encoded by class I region.

Answer 18

HLA-A to HLA-C

HLA-E to HLA-G

Question 19

In class I MHC, name

1) polypeptide chains involved
2) locations of polymorphic residues
3) binding site for T cell coreceptors
4) entities of human MHC

Answer 19

1) a & b2-microglobulin
2) a1 & a2 domains
3) CD8 binds a3 domain
4) HLA-A, HLA-B & HLA-C

Question 20

In class II MHC, name

1) polypeptide chains involved
2) location of polymorphic residues
3) binding site for T cell coreceptors
4) human nomenclature

Answer 20

1) a & b
2) a1 & b1
3) CD4 binds a2 & b2 domains
4) HLA-DP, HLA-DQ & HLA-DR

Question 21

In class I MHC pathway, list

1) type of antigen presenting cells involved
2) responsive T cells
3) site of antigen degradation
4) source of protein antigens
5) enzymes responsible for protein degradation
6) site of peptide loading of MHC
7) molecules for peptide transport

Answer 21

1) all nucleated cells
2) CD8+ T cells
3) proteasome
4) cytosolic/nuclear/membrane proteins
5) b1, b2 & b5 subunits of proteasome
6) endoplasmic reticulum
7) TAP in ER

Question 22

In class II MHC pathway, list

1) types of APC involved
2) responsive T cells
3) site of antigen degradation
4) source of protein antigen
5) enzymes responsible for protein degradation
6) site of peptide loading of MHC
7) molecules for peptide transport

Answer 22

1) DC, macrophage, B cell, endothelial cell, thymic epithelium
2) CD4+ T cells
3) endosome & lysosome
4) endosomal & lysosomal proteins
5) cathepsin
6) late endosome & lysosome
7) invariant chain in ER & Golgi, HLA-DM

Question 23

Name 2 chaperones involved in folding of nascent alpha chain in ER under class I MHC pathway.

Answer 23

Membrane chaperone calnexin

Luminal chaperone calreticulin

Question 24

() promotes assembly of class I MHC with peptides.

Answer 24

Tapasin

Question 25

() trims peptides into appropriate sizes in proteasome.

Answer 25

ERAP (ER associated protease)

Question 26

Give 2 reasons for which peptides transported into ER do not bind class I or II MHC.

Answer 26

Luminal TAP complex with class I MHC
Invariant chain on class II MHC

Question 27

() catalyses dissociation of invariant chain & CLIP from class II MHC.

Answer 27

HLA-DM

Question 28

() recognises lipids & glycolipids displayed by class I-like non-classical MHC molecules called ().

Answer 28

NKT cells

CD1d

Question 29

() recognises proteins, lipids, phosphorylated molecules & alkyl amines which are not presented by MHC molecules (non-MHC restriction).

Answer 29

Gamma delta T cells