Structure of Class I and Class II HLA Antigens

Considerable information is now available about the overall structure of both class I and class II HLA antigens and in the not too distant future should be available in atomic detail in the crystal structures. The present challenge is to relate these structures to the functions of these antigens in presentation of viral antigens in the generation of CTL (class I HLA antigens) or in presentation of foreign antigens to T helper cells in the generation of the antibody response (class II HLA antigens) and in particular to relate their polymorphism to these specific functions.