Major transplantation antigens in host responses to infection.

There is increasing support for the concept that in all of their varied immunologic functions, T lymphocytes act through a dual specificity. In the case of intracellular viral infections, the recognition required for cytolysis involves both a "self" component, coded for by the genes that specify the major transplantation antigens, and an "X" component, provided by viral antigens expressed on the target-cell surface.