Protein tyrosine phosphatase receptor type C (CD45RA) (PTPRC)

Protein tyrosine phosphatase receptor type C (PTPRC), commonly known as CD45, is a transmembrane protein essential for regulating T-cell and B-cell antigen receptor signaling [1]. The CD45RA isoform is a high-molecular-weight variant expressed primarily on naïve T cells, which are lymphocytes that have not yet encountered their specific antigen [2]. CD45RA functions by dephosphorylating the inhibitory tyrosine of Src-family kinases, such as Lck, thereby lowering the threshold for T-cell activation [1, 3]. In clinical medicine, CD45RA+ naïve T cells are significant as the primary mediators of graft-versus-host disease (GVHD) in allogeneic hematopoietic stem cell transplantation [4]. Therapeutic strategies often involve the selective depletion of these cells using monoclonal antibodies or specialized cell-selection systems to prevent GVHD while preserving memory T cells for pathogen defense [4, 5]. Additionally, CD45 is targeted in radioimmunotherapy for hematologic malignancies to deliver cytotoxic radiation directly to leukemic cells [6].

Other names

CD45RACD45Leukocyte common antigenLCAT200PTPRC

Binding to the extracellular domain of CD45/CD45RA to induce cell depletion via antibody-dependent cellular cytotoxicity (ADCC) or to deliver localized radiation.