L6 MHC Locus - Hudig Flashcards
What two proteins make up the MHC I ?
MHC I alpha and B2microglobulin
is B2microglobulin coded with MHC?
no, gene is outside MHC complex
What proteins make up the MHCII?
MHCII alpha and beta chains
Are CD proteins coded with MHC?
NOOPE, on a different chromosome
HOw many alleles of MHC does each person have?
2
is MHC inherited with crossing over?
NO
How many loci are there for MHCI? what are they called?
3; a, b, and c
How many loci are there for MHCII? What are they called?
3; DP, DQ, AND DR
what sets DR apart from DQ and DP?
It encodes two beta chains and one alpha chain instead of one each
Distinguish between multi-allelic and multigenic?
multigenic= three genes come together to make MHC multiallelic:= there are multiple variants of each of the three genes
which MHC I gene has the most alleles?
b
What is the pattern of MHC gene and allele expression?
both are codominant
How many different MHC I proteins will there be on a cell of a completely heterzygous person?
6
What cells would present with six types of MHCI?
all cells except APCs and RBCs
MHCI (blank) maximizes the antigenic peptide presentation in humans
allelic variation
Is it the way the proteasome degrades foreign peptides or MHCI construction that dictates antigen presentation?
MHCI construction, proteasome cuts the same protein up the same in everyone
Each memory CTL needs a match of the same peptide in the (same/any) MHC I (that fits into its TCR) to kill
SAME PEPTIDE IN SAME MHCI, NEEDS TO BE FUCKING IDENTICAL
What do you must have to test CTL anti-viral vaccines?
target cells of the SAME MHCI as the immune donor of the CTLs
Which MHC is inducible on endothelial cells during inflammation?
MHCII
MHC class II allelic polymorphism means that some individuals will be (more/less) able to respond to some pathogens
LESS :(
WHat cells lack both MHCI and II?
RBCs
Neutrophils strongly express which MHC?
MHCI
Which cells express both MHCI and MHCII?
APCs, macrophages, Bcells, and *occasionally T cells
organ specific cells express MHCI or II?
MCHI
What is relative risk?
is the incidence of the disease in individuals bearing the MHC locus/divided by the incidence in the population of individuals lacking the allele.
What happens when preproinsulin binds to DR3, DR4, or DQ8 MHC proteins?
These MHC-peptides are selectively recognized by IDMM Type I immune patients. These anti-self T helpers could then support development of CTL anti-pancreatic beta cell killer cells.
what is the order of importance when looking at barriers to transplantation?
- ABO BLOOD GROUP
- HLA class II
- HLA class I
- minor histocompatibility Ags
What is an autograft?
tissue grafted from the same person OR between two genetically IDENTICAL people
What is an allograft?
grafted between HLA and other loci ALLOGENIC individuals
How quickly are allografts rejected?
within two weeks without immunosuppresion
What is the result when transplant patients are MHC haplotype matched?
better survival and health
Is there any way to have an organ transplant without immunosuppresion?
get your unfortunate twin to cough an organ up fer ya
Can you still have graft rejection even with complete HLA matching?
yes
Do T cells respond with greater frequency to foreign MHC molecules or to self MHC bearing an Ag?
Respond more to foreign MHC (1/100 tcells) while self mHC + Ag (1/1million t cells)
MHCIII genes are non (blank)
allellic
Haplotypes are linked sets of genes inherited as a (blank)
unit
How many MHC haplotypes do you get from each parent?
one
What bug produces super Ags?
staphylococci, staph aureus, including MRSA
What makes something a super Ag?
they bind to a large number of t cells and trigger MASSIVE t cell response
What about their binding pattern makes things super Ags?
they bind to the MHCII and TCR Vbeta receptor simultaneously
Do superAgs bind in the MHCII binding groove?
no
what are two diseases associated with super Ags?
toxic shock syndrome and food poisoning
Can a super ag bind to any TCR Vbeta?
No, only specific ones
What percent of T cells can a given super Ag bind to?
2-20%
What does IL1 do systemically?
release of pyrogens and create a fever
What happens after exposure to enterotoxins?
acute diarrhea