MHC class II molecules are found on:
|A|| Virtually all cells in the body.|
|B|| B cells, dendritic cells and macrophages.|
|C|| Only gamma-interferon activated cells.|
|D|| Virtually all nucleated cells in the body.|
|E||Only on virally-infected cells|
a. The MHC is part of the genome that codes for molecules that are important in immune recognition and rejection of allografts.
b. Complex is present on short arm of chromosome 6.
c. The gene complex contains a large number of individual genes which are grouped into 3 classes.
d. The MHC class I molecules are located on all nucleated cells. They contain two separate non-covalently associated polypeptide chains, the heavier alpha chain(α) and the lighter beta chain(β2 microglobulin).
e. A peptide-binding groove is formed between α1 and α2 helices with beta-pleated sheet as its floor.
f. CD8 T lymphocytes recognizes peptide antigen only when it is presented by the antigen presenting cell in the peptide binding groove of MHC I molecules
g. The class II are located on antigen presenting cells like macrophages, dendritic cells, monocytes, langerhans cells and B cells.
h. MHC class II molecules comprise two non-identical and non-covalently associated polypeptide chains (α and β).
i. A peptide binding groove is formed in between α1 and β1 domains with a beta pleated floor.
j. CD4 T lymphocytes recognizes peptide antigen only when it is presented by the antigen presenting cell in the peptide binding groove of MHC II molecules.
k. Complement components, properdin factor B, heat shock proteins and TNF alpha and beta are encoded by the genes located in the MHC Class III.
HLA Typing →Microcytotoxicity test; Dye used is trypam Blue