THE CD69 RECEPTOR - A MULTIPURPOSE CELL-SURFACE TRIGGER FOR HEMATOPOIETIC-CELLS

CD69 was initially described as being restricted to recently activated lymphoid cells, brat is now known to be expressed on the surface of a ll hematopoietically derived leukocytes. Crosslinking of CD69 generate s intracellular signals in all cell lineages studied, both mouse and h uman, and results in a variety of cellular end I responses. Since a sp ecific ligand has not yet been identified, a definite functional ident ity for CD69 is still missing. However, as discussed here by Roberto T esti and colleagues, the broad expression of CD69 and its conserved ab ility to generate intracellular signals suggests a general role for th e CD69 receptor in the biology of hematopoietic cells.