MHC

Question 0

What chromosome is the MHC complex on?

Answer 0

Human chromosome 6, mouse chromosome 17

Question 1

What important T-cell suppressing drug increased the success of tissue transplantation?

Answer 1

Cyclosporine (disc 1969)

Question 2

What is the MHC gene complex called in mice?

Answer 2

H-2 complex

Question 3

What is the MHC gene complex called in humans?

Answer 3

HLA complex

Question 4

What does HLA stand for?

Answer 4

Human leukocyte antigen

Question 5

MHC is generally inherited as a unit, known as what?

Answer 5

A haplotype

Question 6

How is MHC inherited?

Answer 6

One haplotype from each parent

Question 7

What percentage of the MHC gene product is expressed?

Answer 7

All of it; no allelic exclusion

Question 8

What are the subunits of a class 1 MHC molecule?

Answer 8

α1, α2, α3; β2 microglobulin

Question 9

Where is the binding groove located on the class 1 MHC?

Answer 9

Between subunits α1 and α2

Question 10

What length of peptide Ag is bound by class 1 MHC?

Answer 10

8-10 AA

Question 11

The TCR of the Tc cell binds what on the target cell?

Answer 11

Class 1 MHC molecule α1 and α2 subunits with bound peptide Ag

Question 12

What does CD8 interact with on the target cell?

Answer 12

Class 1 MHC domains α2, α3, and β2 microglobulin

Question 13

Which MHC class 1 subunits exhibit the greatest genetic diversity between individuals?

Answer 13

Subunits α1 and α2

Question 14

What is the gene arrangement of HLA?

Answer 14

Class 2-Class 3-Class 1

Question 15

Class 2 loci contains what genes?

Answer 15

DP, DQ, and DR

Question 16

Class 1 loci contains what genes?

Answer 16

B, C, and A

Question 17

What do the ABC genes of Class 1 encode for?

Answer 17

The α chain

Question 18

What do Class 2 genes DP, DQ, and DR encode?

Answer 18

Both α β chains

Question 19

On what cells are class 1 MHC molecules expressed?

Answer 19

Nearly all uncleared cells

Question 20

What cells exhibit low expression of MHC1?

Answer 20

Hepatocytes

Question 21

What cells exhibit no expression of MHC1?

Answer 21

Sperm, neurons, and erythrocytes

Question 22

What cells express MHC2?

Answer 22

APCs: macrophages, dendritic cells, and B cells

Question 23

Expression of MHC molecules is both _____ and _____.

Answer 23

Coordinate and codominant

Question 24

What is meant by coordinate expression?

Answer 24

All class 1 or 2 genes are expressed at the same time; ex: a dendritic cell will constitutively express HLA-DP, DQ, and DR molecules on its surface at any given time

Question 25

What is meant by codominant expression?

Answer 25

Both maternal and paternal haplotype are expressed

Question 26

Why are MHC genes called polygenic?

Answer 26

Each individual has multiple genes for MHC 1 and 2

Question 27

What 3 things are required for T cell activation?

Answer 27

Ag processing, Ag presenting, MHC must be self

Question 28

What molecule is exogenous Ag presented on?

Answer 28

MHC2

Question 29

What molecule is endogenous Ag presented on?

Answer 29

MHC1

Question 30

What Ags aren't presented on MHC molecules?

Answer 30

Non-protein Ags (lipids and glycolipids)

Question 31

What T cells recognize non-protein Ags?

Answer 31

γδ Τ cells

Question 32

What are "professional" APCs?

Answer 32

Dendritic cells, macrophages, and B cells

Question 33

What are "nonprofessional" APCs?

Answer 33

Fibroblasts (skin), vascular endothelial cells, thymic epithelial cells

Question 34

Where are MHC2 α and β chains synthesized?

Answer 34

Rough endoplasmic reticulum

Question 35

What roles does the invariant chain play?

Answer 35

Acts as a chaperone to ensure correct folding of chains, acts as a peptide blocker to prevent endogenous peptide from binding, acts as a router to transport the MHC2 to the membrane

Question 36

After synthesis, where does the MHC2 + invariant chain complex go?

Answer 36

Acidic, peptide containing endosome

Question 37

Partial digestion of the invariant chain results in only _____ remaining in the MHC2 binding groove

Answer 37

CLIP (class-2 associated invariant chain peptide)

Question 38

CLIP is exchanged for peptide via what protein?

Answer 38

The chaperone HLA-DM

Question 39

What are two examples of endogenous peptide Ag?

Answer 39

Viral proteins, mutated cancer proteins