CD22, soluble

CD22 is a 135 kDa B-cell restricted sialoglycoprotein that binds to oligosaccharides containing 2-6-linked sialic acid residues. It is present in the cytoplasm of nearly all B-lineage cells and is also expressed on the surface of B-cells during advance stages of differentiation. Although the exact physiological function of CD22 is unclear, it appears to play a role in B-cell activation and to act as an adhesion molecule. The potential therapeutic use of CD22 and anti-CD22 may be useful in diagnostic and/or treatment of leukemia, lymphoma, non-Hodgkin's lymphoma and certain autoimmune conditions. (Cesano A. and Gayko U. Semin. Oncol. Apr. 2003 (2) : 253-257) . Recombinant human CD22 is a soluble 75.0 kDa (666 amino acid residues) protein which corresponds to the extracellular domain of CD22.