Uses
CD19 is a 95kDa protein localized on the surface of nearly all B lymphocytes, and is considered to be the specific surface marker for B cells. This protein belongs to the immunoglobulin (Ig) superfamily with a cytoplasmic region of ~240 amino acids, and is involved in the regulation of B cell function. The protein is encoded by the 7.41kb cd19 gene, mapped on the short arm of human chromosome 16p11.2.
There are certain localized regions of strong net negative charge with nine tyrosine residues in the cytoplasmic region of CD19. These regions might regulate the interaction of CD19 with the proto-oncogene Vav, phosphatidylinositol-3 kinase (PI-3 kinase), and the Lyn, Lck, and Fyn protein tyrosine kinases.
Biological Activity
CD19 expression is restricted to normal and malignant B-lineage cells. Therefore, it is considered to be a striking target for immunotherapies aimed at B-cell malignancies. CD19 helps B lymphocytes to initiate primary immune response even at low concentrations of antigen. The encoded protein plays a crucial role in initiating intrinsic B cell signaling thresholds by regulating both B cell receptor (BCR)-dependent and independent signaling. It also functions as a biomarker for B-cell development.
