Encyclopedia of Signaling Molecules

2018 Edition
| Editors: Sangdun Choi


  • Pauline JohnsonEmail author
  • Asanga Samarakoon
  • Amy E. Saunders
  • Kenneth W. Harder
Reference work entry
DOI: https://doi.org/10.1007/978-3-319-67199-4_34


Historical Background

CD45 was first identified by antisera and then by monoclonal antibodies (mAbs) as a major lymphocyte cell surface glycoprotein. CD45 is leukocyte specific, expressed on all hematopoietic cells except red blood cells and this has led to the clinical use of pan-specific CD45 mAbs to identify leukocytes and cells of hematopoietic origin. Some mAbs identify specific isoforms of CD45 that are expressed in a cell type and developmentally regulated manner and are referred to as CD45R mAbs. CD45 isoforms range from 180 to 220 kDa and cloning of the CD45 gene revealed that these isoforms arise by alternative splicing of at least three exons (ABC) that encode a region near the amino terminus of the extracellular domain of CD45 (Thomas 1989; Johnson et al. 1997). The B220 (CD45RABC) isoform of CD45 is expressed primarily on B cells and the...

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Copyright information

© Springer International Publishing AG 2018

Authors and Affiliations

  • Pauline Johnson
    • 1
    Email author
  • Asanga Samarakoon
    • 1
  • Amy E. Saunders
    • 1
  • Kenneth W. Harder
    • 1
  1. 1.Department of Microbiology and Immunology, Life Sciences InstituteUniversity of British ColumbiaVancouverCanada