MHC- Last Part Flashcards
Each MHC locus has _ alleles in an individual
2
MHC molecules have _ major different classes, and each class contains ___________ loci
2
Different
MHC is poly - ________ and poly- _________
Poly- GENIC
Poly- MORPHIC
What is the combination of alleles on the same chromosome?
MHC Haplotype
What do polygyny and polymorphism contribute to an individual?
MHC diversity
Since MHC molecules bind to peptides through _________ _______, although having a limited number of MHC molecules, and individual can mount an _________ __________ against most invaders such as bacteria
Anchor residues
Immune response
___________ MHC 1 and 2 molecules are highly polymorphic in a population
Classical
MHC polymorphism in a population protects a species from being ___________
Eliminated
______________ MHC 1 molecules display similar structure but are _______ polymorphic in a population
Nonclassical
Less
What type of mutation simply changes in individual nucleotides?
Point
What is it called when small blocks of DNA are exchanged between different class 1 genes in a non reciprocal fashion?
Gene conversion
MHC/peptide complexes are not only _________ antigenic peptides to mature _ cells, but also determine T cell repertoire
Present
T
What percent of positive selection occurs in thymus?
3%
What percent of negative selection occurs in thymus?
7%
What percent of death due to neglect occurs in thymus?
90%
The more MHC molecules = the _________ the chance of the presentation of self-antigens
Higher
The higher the chances of the presentation of self-antigens, the _________ the peripheral T cell repertoire
Smaller
The higher the chances of the presentation of self-antigens, the ________ the chances of autoimmune diseases
Higher
What is the consequence of the balance between the resistance of infection and the risk of autoimmunity in an individual?
MHC diversity
How many different MHC la molecules appears to be a reasonable comprise between maximizing the recognition of foreign antigens while at the same time minimizing he chances of recognizing self-antigens, at least in humans?
6
The presence of certain ____ alleles is associated with human disease
HLA
What does DR4 and DQ8 make humans susceptible to?
Type 1 diabetes
What does B57 and B27 make humans susceptible to?
Psoriasis
Ankylosing spondlytitis
Reiters Syndrome
What is B57 and B27 over represented in?
HIV elite controllers
Transplantation rejection is due to immune responses to?
Allogeneic MHC molecules
Cattle has BoLA-DRB3.2*10 and is infected with bovine leukemia virus, you expect the cattle will have ________ pro viral load
High
What are the 2 mechanisms for MHC polymorphism?
Gene conversion
Point mutation
If a cow has BoLA-DRB3.23,7,8,11, *22, *24, *28 alleles, it has ____ proviral loads
Low
What 2 properties make it difficult for pathogens to evade immune responses in a species?
Polygenic and Polymorphic
