MONOCLONAL ANTIBODIES THAT BLOCK LIGAND BINDING TO THE CD22 RECEPTOR IN MATURE B CELLS

摘要

The present invention is concerned with a series of novel monoclonal antibodies directed against CD22, a B lineage-restricted member of the Ig-superfamily which serves as an adhesion receptor expressed by matu re B lymphocytes and is believed to function in the regulation of B cell activation. The monoclonal antibodies (mAb) specifically block red blood cell and leukocyte adhesion (80-100 %) to COS cells transfected with CD22 cDNA and also identify a region of CD22 distinct from those defined by previously described CD22 mAb. The invention also encompasses therapeutic compositions including therapeuticall y effective amounts of a polypeptide comprising the CD22 ligand or portion thereof or of a polypeptide comprising the first two amino - terminal Ig-like domains of CD22, or the ligand binding portion thereof. The antibodies and polypeptides of the invention find use in therapeutic methods for treatment of humans to retard or block CD22 adhesive function, particularly in autoimmune disease.