MHC structure and function

Question 1

MHC located on chrmosome

Answer 1

6

Question 2

what is most polymorphic gene in hman genome

Answer 2

MCH class I and II genes

Question 3

What are the classical prodcuts of Class I genes?

Answer 3

HLA-A, B and C heavy chains

Question 4

What the the classical products of MHC II genes?

Answer 4

heterodimer of HLA- DR, DQ, and DP

alpha and beta chains

Question 5

Three key characteristics of MHC gene

Answer 5

polymorphic
polygeneic
codominant

Question 6

How do T cell regocnize antiG

Answer 6

recognize foreign antigen in context of self MHC

Question 7

Gene products for class II

Answer 7

6 gene products

Question 8

What molecules are responsible for transplant rejection?

Answer 8

MHC I and II thus need to do tissue typing bfore transplant.

Question 9

How many gene products do we match for

Answer 9

10

Question 10

what gene producted is not accounted for during transplant match

Answer 10

HLA-DP

Question 11

Chance of sibling being a match

Answer 11

1:4

Question 12

Class I/II expressed on all nuclearted cells

Answer 12

Class I

Question 13

What makes up Class I structure?

Answer 13

Class I heavy chain will form heterodimer with the light chain Beta2 microgoblulin

Question 14

What type of association is there btwn the beta2micro and heavy chain of MHC 1

Answer 14

non-covalent and alpha chain goes through membrane

Question 15

which domain spans membrane in Class I

Answer 15

alpha 3

Question 16

is the beta 2microgob MCH endoced?

Answer 16

nope

Question 17

Is beta2 micorglobulin polymorphic?

Answer 17

nope

Question 18

what is the B2m structulally related to

Answer 18

immunoglobulin

Question 19

Where are MHC II molecules expressed

Answer 19

only at specialized APCs

Question 20

What does Class II MHC present antiG to

Answer 20

CD4T cells

Question 21

What composes a class II MHC

Answer 21

alpha and beta chain each encoded by different gene

Question 22

which chain of MHC II is more polymorphic

Answer 22

beta chain.. thus only one considrered for tissue typing

Question 23

which domains of MHC II form peptide binding domain?

Answer 23

alpha 1 and beta 1

Question 24

what’s significant about the alpha 2 and beta 2 domains of mch II

Answer 24

these domains fold and form the immunoglobulin fold

Question 25

A TCR recognizes:

Answer 25

combination of peptide and self MHC

Question 26

Where do polymorphisms occur in MHC I

Answer 26

in alpha helices adn beta sheet of the heavy chain

Question 27

Where do polymorphisms occur in MHC II

Answer 27

alpha helices and beta sheets of the beta chain

Question 28

size limit for peptides binding in MHC I groove

Answer 28

8-10 peptides

Question 29

Determined that _________ distinct peps can bind to each class I MHC

Answer 29

>1000

Question 30

T/F: Each type of class I MHC binds to unique set of peptides

Answer 30

true

Question 31

T/F a single nucleated cell expresses 10 to the 5th copies of each class I molecule thus each of the 1000 distinct peptides are presented at least once

Answer 31

False, each expressed 100-4000 copies per cell

Question 32

Class ____ peptides are anchored at the end while Class ____ are not

Answer 32

Class I anchored | Class II not anchored

Question 33

Class II peptides size:

Answer 33

10-16

Question 34

Within a population there are _____ allelic variants thus while individual may be susceptible, population as a whole has protection d/t polymorphic characteristic of MHC

Answer 34

1000

Question 35

High percentage of people that don't respond to Hep B vaccine have:

Answer 35

HLA-DR7

Question 36

This in an inflammatory, possibly autoimmune disease of vertebral joints

Answer 36

Anklyosing spondoytis

Question 37

That HLA marker is responsible for predisposing ppl to AS

Answer 37

B27

Question 38

HLA B27 found in : | but ___% with this will have AS

Answer 38

6% population | 93% get AS