MHC Flashcards
what do extracellular PAMPs trigger?
PRR to (capture, process & present - APC) to MHC II cells
what does MHC II lead to?
humoral immunity (antibodies - circulating, compliment)
what are examples of extracellular PAMPs?
parasite, worms, fungi, bacteria
what are examples of intracellular PAMPs?
virus, protozoa, bacteria
what does intracellular PAMPs trigger?
MHC I, CD4+ T cells
what does MHC II, CD4+ T cells lead to?
cell-dependent immunity (antibodies, complement, macrophage)
what is the difference between cell-dependent immunity (MHC II) and humoral immunity (CD8+)?
cell-dependent has macrophage involvement
where are MHC I found?
all nucleated cells
where is MHC II found?
dendritic cells (blood, mucous membranes, lymph nodes), macrophage, B cells
how do the antigen proteins enter the cell in MHC I (intracellular)?
pathogen makes own proteins in cells (endogenous proteins)
bacterial endogenous protein enters host cell and goes to proteosome (degrades bacterial protein into fragments) - 10-15AA
what happens to the small bacterial proteins in MHC I (after interaction with proteosome)?
enter the RER (via TAP transporters), where the bacterial protein is broken down even more (8-10AA)
where are MHC1 proteins made within the cell?
by ribosomes in RER
how does MHC 1 interact with small bacterial proteins?
MHC1 has peptide binding cleft (variable region) - temp covered
MHC1 chaperoned to TAP transporter (where bacterial protein broken down further)
MHC1 interacts with small bacterial peptide fragment (via peptide binding cleft) - unique, specific
what happens after MHC1 and small bacterial protein interaction if they are complimentary?
complex leaves RER via endosome –> golgi apparatus –> exocytosis, to be presented on cell surface (APC)
what happens after the complex is presented on cell surface (APC)?
wait for interaction with CD8+ T cell - specific interaction
if complimentary, then can trigger cell-dependent immunity (macrophage, antibodies, complement
