Antigen Presentation and MHC

Question 1

MHC proteins

Answer 1

the spoon feeding protein

expressed on the surface of nucleated cells

Question 2

MCH haplotype

Answer 2

total set of MHC genes on each chromosome. Inherit one haplotype from each parent

Question 3

polygenic

Answer 3

multiple different genes within each individual

Question 4

Polymorphic

Answer 4

multiple varients of each gene exist in the population

Question 5

codominant

Answer 5

alleles on both chromosomes will be expressed simultaneously

Question 6

Which MHC genes code for class I

Answer 6

A,B,C genes

Question 7

Which MHC genes code for class II

Answer 7

D region genes

Question 8

Cell types where class I MHC proteins are found

Answer 8

expressed on nearly all nucleated body cells

Question 9

Cell types where class II MHC proteins are found

Answer 9

professional antigen present cells (ex. dendritic cells, macrophages, and B lymphocytes)

Question 10

Structure of class I MHC proteins

Answer 10

large cleft

ends of cleft are pinched in

Question 11

Function of class I MHC proteins

Answer 11

hold foreign peptides, recognized by the T cell antigen receptor of CD8T lymphocytes

Question 12

Function of class II MHC proteins

Answer 12

hold foregin peptides, recognized by CD4T lymphcytes

Question 13

Structure of Class II MHC proteins

Answer 13

can hold larger peptides than class I because cleft is open at the ends (foot long hotdog in regular size bun)

Question 14

Why is there polymorphism among MHC proteins

Answer 14

allows different individuals to bind a broad range of antigens, thereby conferring a protective advantage on the population

Question 15

Class I pathway

Answer 15

peptide class I MHC complexes formed in ER
shuttle out to plasma membrane of virally infected cell
alerts T lymphocytes that cell is infected
in uninfected cells, class I MHC proteins bind to self peptides

Question 16

Class II pathway

Answer 16

Class II MHC proteins bound by MHC class II associated invarient chain to prevent binding of cellular proteins
vesicles fuse with plasma membrane
in absence of antigen, class II MHC binds to self peptides

Question 17

Importance of MHC protein peptide binding region during presentation of antigen to T lymphocytess

Answer 17

T lymphocytes can only respond to processed antigen presenting on MHC proteins
T lymphocytes can’t recognize/respond to nonprotein antigens because they can’t bind to MHC proteins

Question 18

2 clinical uses for MHC typing of leukocytes

Answer 18

Organ transplant, Paternity testing