Immuno 3 MHC 1 Flashcards
1
Q
HLA System
- what is it?
- another name?
- code for?
- what do they mark?
A
- A complex of genes on the short arm of chromosome six
- Major Histocompatibility Complex (MHC)
- Code for HLA molecules that are expressed on the surface of all nucleated cells
- HLA genes are most polymorphic genes in the human genome.
- HLA antigens are the markers of “Self” for the immune system
- Foreign HLA provoke a storng immune repsonse
2
Q
Defining new HLA: antigens using multiparous Sera
A
- isolate lymphotcytes from blood of many individuals -this is your cell panel
- expose cells to serum you are testing
- note which cells are reactive in cytotoxicity test
- send serum to other HLAD labs to test
- establish a conesus that this serum can identify HLA-something
3
Q
Serological HLA nomenclature
A
- letter for the genetic locus
- accession number - official number of antigen on that locus recognized
4
Q
HLA terinology
- antigen?
- allele?
A
- antigen is specific for one of the HLA gene products
- HLA “allele” is a unique HLA antigen, as defined by sequencing the DNA o the gene of an individual
5
Q
Frequencies of HLA antigens
A
- Each HLA antigen has a unique frequency which will varies according to the ethnic group of the individual
- Frequencies vary due to geographical isolation of mutations occurring early in human history
6
Q
Distribution of HLA Class I and Class II Molecules on Lymphocytes
- T-cells?
- B- cells?
- Platelets?
A
- T-cells
- HLA A, B, and C when resting
- HLA A,B,C, DR, DQ, when activated - B cells
- HLA A, B, C, DR + DQ - Platelets
- HLA A, B, C only
7
Q
Genetics of HLA Antigens
- name of Block of block of genes?
- what group?
- how many haplotypes?
- inheritance?
A
- Inherited together as a group on chromosome 6
- block of gene is called a haplotye
- each individual has two haplotypes
- two haplotypes comprise the persons genotypes
- Inheritance is Mendelian and co-dominant
