Protein tyrosine phosphatase receptor type C, CD45RA isoform (CD45RA)

CD45RA is an isoform of the protein tyrosine phosphatase receptor type C (PTPRC), a large type I transmembrane glycoprotein highly expressed on the surface of nearly all hematopoietic cells except erythrocytes and plasma cells[1][5]. CD45RA is generated by alternative splicing that includes the "A" exon, and its expression identifies naive T lymphocytes, certain B cells, and is used to distinguish between immune cell subsets in both clinical and research settings[3][4][5][7]. CD45RA plays a central role in immune signaling, particularly in regulating the activation threshold of lymphocytes via dephosphorylation of tyrosine kinases critical for T and B cell receptor signaling (e.g., Lck)[1][5][9]. Alterations, such as polymorphisms and differential splicing, can impact immune functions and are implicated in disorders such as immunodeficiency, autoimmunity, and inflammation[2]. As a biomarker, CD45RA is prominent in flow cytometry panels for immune profiling and patient selection in cellular therapies, yet direct therapeutic targeting may cause broad immune impairment due to its expression on many lymphocyte subsets[1][3][7][9].

Other names

CD45RAReceptor-type tyrosine-protein phosphatase C, CD45 isoform RAPTPRC (gene encoding the protein)Leukocyte common antigen isoform RALCA-RA

Antibody-mediated cell depletion (targeting CD45RA-expressing cells for depletion) Cell surface labeling (flow cytometry, selection of naive T cell populations) Potential modulation of immune cell signaling via phosphatase activity inhibition (experimental)