On the trail of empty MHC class-I

Since being proposed nearly 25 years ago that MHC-I molecules free of peptide ligand possess a conformation that is distinct from that of the mature loaded form, considerable research has been conducted in order to isolate and characterise such a species. While some progress has been made in our understanding, many questions still surround the nature and loading of empty MHC-I. However, the necessary tools to address these questions may finally be at hand.

► Overview of MHC class-I assembly and loading. ► Current status of research into the nature of empty MHC class-I molecules. ► Developments and future directions in the study of empty MHC-I.