MHCⅡ类抗原基因为免疫应答基因,它控制着动物机体对某一特定抗原应答的特异性T细胞的产生与否。完成控制的机制还不十分清楚。而且,该基因的多效性,即它们控制着许多似乎是互不相关的性状这一事实,使人们对其本质更为困惑不解。特别是,T细胞的同种异体反应性和MHC限制性这两种现象代表着多年来一直未能回答的主要问题。 MHC class II antigen gene is an immune response gene that controls the production of specific T cells that respond to a particular antigen in the body of an animal. The mechanism for completing the control is not yet clear. Moreover, the pleiotropy of the genes, that is, the fact that they control many seemingly unrelated traits, makes people more puzzled by their nature. In particular, both T cell alloreactivity and MHC restriction represent the main problems that have not been answered for many years.