Protein tyrosine phosphatase receptor type C isoform RA (CD45RA)

Protein tyrosine phosphatase receptor type C isoform RA (CD45RA) is a high-molecular-weight variant of the CD45 antigen, a transmembrane glycoprotein expressed on all hematopoietic cells except mature erythrocytes [1, 15]. CD45RA is specifically found on naïve T cells and is produced by the alternative splicing of exons 4, 5, and 6 of the PTPRC gene [7, 15]. As a receptor-type protein tyrosine phosphatase, it plays a vital role in regulating T cell receptor (TCR) signaling by dephosphorylating and activating Src family kinases such as Lck and Fyn [12, 17]. In clinical medicine, CD45RA is a primary target for selective T cell depletion in allogeneic hematopoietic stem cell transplantation (HSCT) [1, 4]. By depleting CD45RA+ naïve T cells from donor grafts, the risk of severe graft-versus-host disease (GVHD) is minimized, as these cells are the main drivers of alloreactivity [1, 8]. Simultaneously, the preservation of CD45RO+ memory T cells ensures that the recipient retains immunity against pathogens and maintains a graft-versus-leukemia effect, leading to improved clinical outcomes in mismatched or haploidentical transplants [4, 5]. This targeted approach allows for rapid immune reconstitution and reduced viral complications compared to broad T cell depletion strategies [4].

Other names

CD45RAPTPRC isoform RALeukocyte common antigen RACD45RT200 isoform RA

Selective depletion of naïve T cells from hematopoietic stem cell grafts to reduce alloreactivity and prevent graft-versus-host disease while maintaining memory T cell-mediated immunity.