CD45 (C-Term) Rabbit Monoclonal Antibody (Clone RM291)

CD45 is a type I transmembrane glycoprotein that is encoded by the PTPRC gene in humans and is abundantly expressed on nucleated hematopoietic cells.¹ It contains an extracellular region that binds to glycoproteins and exists in various isoforms in a cell type-, differentiation state-, and activation state-dependent manner.^1,2 CD45 also contains two highly conserved cytoplasmic protein tyrosine phosphatase domains that regulate intracellular signaling.¹ CD45 functions as a negative or positive regulator of antigen receptor signaling in T and B cells through dephosphorylation of Src family kinases in a cell type- and differentiation state-dependent manner.² It also dephosphorylates JAK kinases, inhibiting cytokine and chemokine signaling in leukocytes. Mutations in PTPRC are associated with severe combined immunodeficiency (SCID) in mice and humans.^3,4,5 The number of CD45+ cells is increased in postmortem brain from patients with Alzheimer's disease.⁶ Increased levels of the CD45 isoform CD45RO have been found on CD19+ lamina propria B cells isolated from patients with Crohn's disease.² Fluorescently labeled versions of CD45 have commonly been used in flow cytometry as a pan leukocyte marker and to identify certain subsets of hematopoietic stem cells (HSCs).⁷ Cayman's CD45 Monoclonal Antibody (Clone RM291) can be used for immunohistochemistry (IHC) and Western blot (WB) applications.

WARNING This product is not for human or veterinary use.

1. Irie-Sasaki, J., Sasaki, T., and Penninger, J.M. CD45 regulated signaling pathways. Curr. Top. Med. Chem. 3(7), 783-796 (2003).

2. Rheinländer, A., Schraven, B., and Bommhardt, U. CD45 in human physiology and clinical medicine. Immunol. Lett. 196, 22-32 (2018).

3. Hermiston, M.L., Xu, Z., and Weiss, A. CD45: A critical regulator of signaling thresholds in immune cells. Annu. Rev. Immunol. 21, 107-137 (2003).

4. Kung, C., Pingel, J.T., Heikinheimo, M., et al. Mutations in the tyrosine phosphatase CD45 gene in a child with severe combined immunodeficiency disease. Nat. Med. 6(3), 343-345 (2000).

5. Tchilian, E.Z., Wallace, D.L., Wells, R.S., et al. A deletion in the gene encoding the CD45 antigen in a patient with SCID. J. Immunol. 166(2), 1308-1313 (2001).

6. Hopperton, K.E., Mohammad, D., Trépanier, M.O., et al. Markers of microglia in post-mortem brain samples from patients with Alzheimer’s disease: A systematic review. Mol. Psychiatry 23(2), 177-198 (2018).

7. McKinney-Freeman, S.L., Naveiras, O., Yates, F., et al. Surface antigen phenotypes of hematopoietic stem cells from embryos and murine embryonic stem cells. Blood 114(2), 268-278 (2009).