Major Histocompatibility Complex I and II Flashcards
Features of Major Histocompatibility Complex
Encoded by HLA genes; present antigen fragments to T-cells and bind TCRs
MHC-I loci
HLA-A; HLA-B; HLA-C
MHC-I binds to…
TCR and CD8
Structure of MHC-I
1 long chain and 1 short chain
Cells that express MHC-I are…
all nucleated cells, APCs, platelets; not on RBCs
Function of MHC-I
Present endogenously synthesized antigens (viral or cytosolic proteins) to CD8+ cytotoxic T cells
Antigen loading MHC-I steps
Antigen peptides loaded onto MHC-I in RER after delivery via TAP
MHC-I associated structures
beta-2 microglobulin
MHC-II loci
HLA-DP, HLA-DQ, HLA-DR
MHC-II bind to…
TCRs and CD4
MHC-II structure
2 equal length chains
Cells that express MHC-II are…
APCs
Function of MHC-II
Present exogenously synthesized antigens (bacterial proteins) to CD4+ helper T-cells
Antigen loading MHC-II steps
Antigen loaded following release of invariant chain in an acidified endosome
MHC-II associated structures
Invariant chain