Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
17 Cards in this Set
- Front
- Back
|
Differences of MHC compared to Ig and TCR
|
Encoded by conventional stable genes; no rearangements
multiallelic - accounts for polymorphism Helps T Cells see antigen? |
|
|
Most Polymorphic of Class I MHC
|
A,B,C
Polymorphic involved in Antigen presentation Monomorphic is for recognition by NK cells |
|
|
What chromosome is MHC encoded on and how is it inherited?
|
Chromosome 6
Inherited as a unit or haplotype each person receives two one from mother and father |
|
|
What role does MHC play in organ transplantation?
|
It allows it basically to be accepted or not.
25% chance both haplotypes match 50% chance 1 haplotype will match if given from parent But the best is from a sibling |
|
|
What type of cells do class I and II MHC distribute on?
|
Class I: All nucleated cells (not erythrocytes)
Class II: Restricted to professional antigen presenting cells ( T, B, Macs, etc..) |
|
|
What does the Beta 2 microglobulin do for Class I?
|
Allows it to leave the ER
|
|
|
Where are peptides anchored on Class I MHC?
|
Anchored on both ends
|
|
|
What is the structural diffence between class I and Class II
|
peptide binding cleft of II is not closed at the ends
Results are peptides are less uniform in size |
|
|
Different MHC isoforms bind different peptides
|
Reason for polymorphism
Selective peptide binding Not antigen specific One isoform can bind many different peptides with the same overall shape |
|
|
What do non-polymorphic areas bind?
|
CD4 for Class II
CD8 for Class I |
|
|
What size of peptide do Class I and II bind?
|
Class I with shorter peptides b/c bound at both ends
Class II more variable in size b/c not constrained |
|
|
What class prefers exogeneous?
|
MHC class II for presentation to CD4+
|
|
|
What class prefers endogeneous?
|
MHC class I for presesntation to CD8+
|
|
|
What does binding of the invariant chain to MHC Class II do?
|
Prevents binding of peptides in the ER
|
|
|
What does HLA-DM do?
|
Helps remove the invariant chain from Class II and leaves behind in the peptide cleft a small residue called CLIP.
Then removes CLIP and Class II can now be moved to surface to be recognized by CD4+ |
|
|
What do chaperones do?
|
Aid in the proper folding of Class II formation of dimers
|
|
|
TAP transporter
|
Transports peptides to ER after they were degraded proteins marked with ubuquitin by a Proteosome
|
