MHC Polymorphisms and Functions Flashcards
What are the roles of the subunits found in proteosomes?
They insure that the peptide is 8 to 10 aa long
A mutation in which protein will cause anergy?
B7
What three cell types are classified as professional antigen presenting cells?
Dendritic cells
Macrophages
B lymphocytes.
How are CD1 molecules unique?
They share structural similarities with classical MHC I but are functionally similar to MHC II
What needs to happen before an antigen can be presented to a T cell?
It must be processed first
Various types of T cells (expressing_____________receptors , can react against __________ antigens, such as mycolic acid, derived from well-known pathogens, such a ______________
gamma Delta ; lipid; Mycobacterium tuberculosis .
Immunoflurescent labeling
used to determine importances of the trimeric protein, CD74, in transporting the MHC II molecule out of the rER
HIV progression is associated with which susceptibility allele? Which protective allele? Which population?
B35; A1-B8-DR3
B27
USA, EUROPE
Cells that display peptides associated with class I MHC molecules to CD8+ Tc cells are referred to as target cells____________.
Cells that display peptides associated with class II MHC molecules to CD4 + TH cells are called ____________
Target cells
antigen-presenting cells (APCs).
Peptides assemble with class II MHC molecules by displacing____________
CLIP
Which enzymes are found in lysosomes?
Proteases
Nucleases
Glucosidases
Lipases
Phospholipases
Phosphatase
How do professional antigen presenting cells differ from each other?
In their mechanisms of :
- Antigen uptake
- Whether they constitutively express class II MHC molecules.
- In their costimulatory activity
How are macrophages activated?
By phagocytosis of particulate antigens before they express class II MHC molecules or by costimulatory membrane molecules such as B7.
Which cells are the most effective antigen presenting cells? Why?
Dendritic cells because they constitutively express a high level of class II MHC molecules, they have costimulatory signals, and they can activate naive TH cells
What is CLIP?
It is a small part of the trimeric protein that rest directly in the peptide binding cleft preventing the binding of endogenous antigens.
B cells internalize antigen very effectively by ____________ using antigen-specific membrane antibody as the receptor.
receptor mediated endocytosis
Classical genes on MHC
HLA-A, HLA-B, HLA-C
What role does pH play in peptide binding?
A neutral pH allows for the disassembly of the CLIP- cleft complex, which allows for a peptide to fully bind to the complex. A neutral pH is found on the surface of the membrane