Out, Damned CLIP! Out, I Say! Paul A. Roche

摘要

Major histocompatibility complex (MHC) class II molecules are the billboards of the immune system. Peptides derived from foreign proteins are inserted into MHC's binding groove and displayed on the surface of antigen-presenting cells (APCs). These pep-tides are then recognized by T lymphocytes so that the immune system is alerted to the presence of foreign material. One of the most hotly investigated topics in immunology ,js the mechanism by which these antigenic peptides are generated and bind to class II molecules within APCs. In this issue, a major advance in our understanding of this process has been achieved: Weber et al. describe how the antigen-processing protein human leukocyte antigen (HLA)-DM (DM) facilitates the insertion of foreign peptides into the groove.