HLA Region

Question 1

what are polymorphic genes

Answer 1

different alleles that are present in the genes

Question 2

what is co-dominant expression

Answer 2

both parental alleles of each mhc gene are expressed at the same point

Question 3

what are the cell types for expressing mhc class II

Answer 3

dendritic cells, macrophages, b cells

Question 4

what are the cell types for expressing mhc class I

Answer 4

all nucleated cells

Question 5

why is it important for mhc class I to be polymorphic

Answer 5

becauase mhc class I is a part of the endogenous pathway to present every endogenous antigen that’s possible

Question 6

for hla class I why is it important you have three different genes and what are they

Answer 6

its important to have three different genes because all three can present antigens and the gives more potential for a more functional immune system a HLA-A HLA-B HLA-C

Question 7

what causes variability in the HLA genes and why is this good

Answer 7

there are a high number of alleles in each gene just in case one went wrong you have another to back it up

Question 8

what are common alleles

Answer 8

they are alleles that when expressed have the same binding pocket and tend to pick up the same peptides which is the commonality between them

Question 9

what are non classical hla genes are what are they useful for

Answer 9

HLA-E HLA-F HLA-G non classical genes are less polymorphic

Question 10

what are classical hla genes and what are they useful for

Answer 10

they are involved in the presentation of peptides to CD8+ cells

Question 11

what are the three main ways to protect foetus in the maternal-foetal interface

Answer 11

cytokine shift, influence of female sex hormones and unique hla expressions by trophoblasts

Question 12

functions of hla e

Answer 12

hla resides on the surface of placental cells and trophoblasts, they intract with NK cells to see if anything needs to be broken down

Question 13

what are trophoblasts

Answer 13

are the outer layer of cells forom the blastocyst are it provides nutrients to cell

Question 14

functions of hla g

Answer 14

activates maternal t-regs and inhibits maternal natural killer cells to cause cell death

Question 15

what genes play a role when a cell becomes stressed and what do they do

Answer 15

MICA and MICB genes and they activate natural killer cells

Question 16

what are the subtypes of classical class II molecules and their role

Answer 16

HLA -DR
HLA- DQ
HLA -DP
they make their own mhc and they are involved on presenting exogenous antigen for recognition by CD4 t cells

Question 17

why is important to have multiple HLA D genes

Answer 17

if one fails or is comprised there are other genes that are back ups

Question 18

what does it mean when HLA-DRB it made to non-polymorphic alpha chains

Answer 18

alpha chains are identical

Question 19

are the beta chains in HLA_DRB non-polymorphic or polymorphic

Answer 19

they are VERY polymorphic to make up the fact the alpha are not

Question 20

what does oilogomorphic mean

Answer 20

a little bit of polymorphism but not much

Question 21

how are HLA class I or class II expressed

Answer 21

they are expressed in a co-dominant matter

Question 22

what is linkage disequilibrium

Answer 22

the non random association of alleles at different loci in a given population with a higher or lower chance of being associated whereas normally it would be inherited randomly

Question 23

what are haplotypes

Answer 23

group of genes inherited together from single parent