CDW50 AND ICAM-3 - 2 NAMES FOR THE SAME MOLECULE

CDw50 differentiation antigen is a molecule broadly expressed on hemat opoetic cells but not on other cells. Previous experiments showed that CDw50 monoclonal antibodies (mAb) inhibited primary mixed lymphocyte culture (MLC). To understand the function of CDw50 better, we purified it and obtained peptide sequence. At the same time, intercellular adh esion molecule (ICAM)-3, the third ligand of lymphocyte function-assoc iated molecule 1, was described by mAb and subsequent cDNA cloning. Im munochemical, functional, and protein sequencing studies show that ICA M-3 and CDw50 are the same glycoprotein, a 120-kDa surface molecule wi th presumably an important role in the immune responses.