What is the role of class II MHC proteins on donor cells in the process of graft rejection?
|A||They are recognized by helper T cells, which then activate cytotoxic T cells to kill the donor cells|
|B||They are the receptors for interleukin-2, which is produced by macrophages when they attack the donor cells|
|C||They cause the release of perforins to lyse the cells|
|D||They induce IgE, which mediates graft rejection|
They are recognized by helper T cells, which then activate cytotoxic T cells to kill the donor cells
In acute graft rejection donor’s class II MHC proteins are recognized by host’s T helper cells. These T helper cells in turn activate Cytotoxic T cell, which kill the donor’s cells. Therefore, acute graft rejection mimics delayed hypersensitivity reaction.