Image redrawn from Ann Rev Biochem, 72:717–42, 2003
Antigens bound by major histocompatibility complex (MHC) molecules interact with T-cell receptors (TCRs) at the heart of the interface for T-cell recognition. But, many other players are involved. Massive polyvalency within this confined space may compensate for low-affinity receptors, giving added sensitivity.
In some ways, science resembles gold mining: Eager practitioners congregate around rich veins of discovery while leaving less-promising territory nearly deserted. Yet even neglected are as can produce a mother lode.
So it has been with cell-cell recognition. Despite its importance in almost every aspect of development, organ function, and in the hematopoietic and nervous systems, the molecular basis of cellular recognition has failed to incite a scientific gold rush, largely due to the daunting technical difficulties in working with membranes, membrane proteins, and their cytoskeletal underpinnings.
Scientific prospectors, though, are migrating to the field in ever-greater numbers, thanks largely ...
