Major Histocompatibility Complex Lecture

Question 1

The major histocompatibility complex (MHC) was discovered through

Answer 1

transplantation studies

Question 2

Products of genes in the MHC region of the genome are responsible for

Answer 2

rapid rejection of tissue grafts

Question 3

MHC are

Answer 3

polymorphic
each common variant of a polymorphic gene is called an allele

Question 4

syngeneic

Answer 4

inbreed sibling mice for around 20 generations-offspring genetically identical- will accept others tissue grafts
inbred strain

Question 5

allogeneic

Answer 5

different inbred strains- will not accept tissue grafts from another inbred strain

Question 6

Congenic

Answer 6

identical at all loci except the trait that you select, and for which you bred them
developed by a cross between 2 inbred straisn

Question 7

MHC genes control

Answer 7

allograft rejection

Question 8

MHC’s real job

Answer 8

present Ag epitopes to TCRs and are recognized together with the epitopes by the TCR

Question 9

2 classes of MHC molecules

Answer 9

class I
Class II

Question 10

Both classes of MHC are

Answer 10

polymorphic
structurally distinct but homologous proteins

Question 11

MHC classes are _____ expressed

Answer 11

co-dominantly expressed

Question 12

Co-dominant expression

Answer 12

products of the alleles on each chromosome are expressed on a cell at the same time

Question 13

A gene on a chromosome is a

Answer 13

haplotype

Question 14

Class I molecules present epitopes to

Answer 14

CD8+ T cells

Question 15

Class I molecules are expressed on

Answer 15

all nucleated cells on the body

Question 16

Class II molecules present epitopes to

Answer 16

CD4+ T cells

Question 17

Class II molecules are expressed on

Answer 17

APCs: Macs, Dendritic cells, B cells
often differentially regulated

Question 18

each MHC molecule consists of

Answer 18

extracellular, peptide-binding groove and is anchored through a transmembrane and cytoplasmic domain

Question 19

Polymorphism of MHC molecules is due to

Answer 19

AA residues in and adjacent to the peptide-binding groove

Question 20

Non-polymorphic, extracellular lg domains contain

Answer 20

binding sites for the T cell surface “markers” CD4 or CD8

Question 21

Each class I or class II molecule has a single

Answer 21

peptide binding cleft that can accommodate many different peptides

Question 22

epitopes that trigger specific T cells compete with

Answer 22

each other for MHC molecule binding cleft

Question 23

MHC molecules present peptide Ags from

Answer 23

different cellular locations

Question 24

Class I molecules present peptides from where

Answer 24

cytosol

Question 25

Class II presents peptides from

Answer 25

extracellular

Question 26

Class I molecules are _____ expressed on

Answer 26

constitutively
essentially ALL nucleated cells

Question 27

Class II are usually expressed only on

Answer 27

Antigen Presenting Cells

Question 28

Class II expression is up-regulated by

Answer 28

cytokines during both innate and adaptive immune responses