Chapter 8 Flashcards
MHC molecules:
are recognized by T cells.
A mutation in which part of a viral protein might allow the virus to evade the adaptive immune response because it MHC binding?
An anchor residue
MHC polymorphisms tend to cluster:
in the peptide-binding groove.
How many different MHC classical class I proteins does each nucleated cell in a human heterozygous at the MHC locus express?
Six
Which of the following would be the MOST likely source of a peptide bound to an MHC class I molecule?
The cytoplasm
One way a developing fetus is protected from attack by the maternal immune system is:
expression on nonclassical class I molecules.
Which of the following is NOT a mouse MHC gene?
DP
Peptide binding diversity is increased by:
Both A and B
Your chances of having the same MHC haplotype as your sibling are:
1:4.
The human MHC locus is one of the most polymorphic regions of the genome. What does this mean?
There are many different alleles of these genes.
MHC diversity ultimately affects the:
variety of peptides that bind to MHC.
Which of the following BEST represents the relationship of polypeptide units in MHC class II?
Only α and β chains from the same gene can pair with each other.
Tasmanian devils are a largely inbred population with little diversity in the MHC. Which of the following would be a likely outcome of this?
They would be at higher risk of infection.
Which of the following cell types would be LEAST likely to express MHC class II?
T cells
Which of the following cell types would be MOST likely to express MHC class I?
All of the above
Which of the following is the BEST example of self-MHC restriction of T cells?
A T-cell clone only recognizes foreign peptides when presented by self MHC.
Under which of the following conditions would T-cell activation be LEAST likely to occur?
Macrophages are fixed with paraformaldehyde, then incubated with antigen, then incubated with antigen-specific T cells.
Place the class I processing pathway in the correct order:
Proteins are digested by the proteasome > peptides are imported into the ER by TAP > peptides are loaded onto MHC class I > class I is exported to the cell surface
In people infected with human cytomegalovirus, class I MHC and β2-microglobulin are produced, but very little mature class I MHC is found at the cell surface. Inhibition of which of the following molecules by human cytomegalovirus may account for this phenomenon?
TAP
T-cell activation can be inhibited by treating antigen-presenting cells with chloroquine. What is chloroquine’s mechanism of action?
It increases the pH of the lysosome.
What is the role of the invariant chain (Ii)?
All of the above
A mutation that renders the MHC class II molecule DM nonfunctional would likely lead to:
cells with class II MHC only bound with CLIP.
Which of the following is an example of cross-presentation?
An exogenous peptide being presented on MHC class I
