Which type of molecules are the most frequent target of allogeneic immune responses against transplanted organs and why?
A)Endothelial adhesion molecules,because they are present in the blood vessels of grafted organs,where donor lymphocytes can interact with them
B)Human leukocyte antigens (HLA),because they are the most polymorphic proteins in the organs.
C)Lipids,because they easily cross through the membranes of lymphocytes
D)Polymorphic cytosolic proteins,because they are readily processed into peptides that can bind class I MHC molecules
E)Blood group antigens,because they are expressed on all red blood cells and endothelial cells

Question

Quizplus · Accepted Answer

The genes encoding HLA molecules,which include class I and class II major histocompatibility complex (MHC)proteins are the most polymorphic genes in the genome,with thousands of different alleles.Therefore,allogeneic responses against HLA proteins are more likely to occur than any against other type of molecules,including endothelial adhesion molecules or cytosolic proteins.Since HLA molecules are present on graft endothelial cell membranes,they are also easily seen by recipient antibodies and T cells.Differences in blood group antigens between donor and recipient are screened for and transplantation between blood group incompatible individuals is rarely performed.

Which Type of Molecules Are the Most Frequent Target of Allogeneic