STRUCTURAL COMPARTMENTALIZATION OF MHC CLASS-II SIGNALING FUNCTION

Major histocompatibility complex (MHC) class II molecules are critical restricting elements in the generation of thymus-dependent immune res ponses. Recent studies indicate that in addition to providing a compos ite epitope for recognition by T-cell antigen receptors, MHC class II molecules function in signal transduction through interaction with oth er cellular proteins. Mutational analyses indicate that structural inf ormation necessary for these functions is compartmentalized in differe nt aspects of the molecular complex. Here, William Wade and colleagues review the structual basis of this MHC class II function as defined i n the I-Aalpha and -beta chains.