Structures and receptor recognition mechanism of HLA molecules

Abstract

Human Leukocyte Antigens (HLAs) are glycoproteins that exhibit unusually high genetic polymorphism as well as high polygenecity by forming a wide variety of gene families. HLAs generally display peptides derived from intracellular proteins to T cells, and furthermore, they interact with various immune cell surface receptors to control broad aspects of immune responses pleiotropically, resulting in the maintenance of homeostasis in our body. X-ray crystallography has remarkably contributed to understanding of precise mechanisms for these HLA interactions. In this issue, we describe molecular structures of HLAs and HLA-receptor complexes, showing how HLA molecules regulate immune responses, and further discuss about their relationship with diseases.