Table 3.

Characteristics of CD22 that make it a good target for antibody-based therapy

•The normal function of CD22 is to regulate signal transduction of the surface immunoglobulin receptors on B cells.
•CD22 is expressed on the cells of the majority of B-lymphocyte malignancies.
•It is not expressed on hematopoietic stem cells or any other nonlymphoid hematopoietic or nonhematopoietic cells.
•Memory B cells do not express CD22.
•Based on in vitro testing of human cell lines, CD22 is one of the better internalizing molecules among several B-lymphoid lineage-specific surface antigens.
•CD22 is not shed into the extracellular environment.