CD45 antibody human specific - HS-427 003

CD45, also designated as Leukocyte Common Antigen (LCA) or protein tyrosine phosphatase receptor type C (PTPRC), is a type I transmembrane protein expressed on all nucleated cells of the hematopoietic system, except mature erythrocytes and platelets (1). Several isoforms of CD45 have been identified which are generated by differential splicing of exons 4, 5, and 6, thereby generating the CD45RA, RB and RC isoforms, respectively (2). Expression of the isoforms differs according to cell type and functional status. The CD45RABC (B220) long isoform is almost exclusively expressed on B cells (3). Naïve human T cells express the high molecular weight isoform CD45RA. Activation of T cells and differentiation to memory T cells is accompanied by exon exclusion for production of the short isoform CD45RO (3). CD45 has been shown to be an essential regulator of T- and B-cell antigen receptor signaling. Thus, CD45-deficient humans and mice develop a severe-combined immunodeficiency (SCID) phenotype (4). In macrophages, CD45 plays a central role in their adhesion, morphology and motility (5).