DOI: 10.1615/CritRevImmunol.v23.i56.40

20 pages

	Download article
	Download MARC record
	Add to Citation Manager Click EndNote icon to dowload the citation in the EndNote format Click RefWorks icon to dowload the citation in the RefWorks format

A Cell Death Pathway Induced by Antibody-Mediated Cross-Linking of CD45 on Lymphocytes

Ann-Muriel Steff
MetrioGene Biosciences Inc., 6100 Royalmount Av., Montreal, QC, Canada, H4P 2R2

Marylene Fortin
MetrioGene Biosciences Inc., 6100 Royalmount Av., Montreal, QC, Canada, H4P 2R2

Fabianne Philippoussis
MetrioGene Biosciences Inc., 6100 Royalmount Av., Montreal, QC, Canada, H4P 2R2

Sylvie Lesage
Centre de Recherche du CHUM, Laboratoire d’Immunoregulation, Universite de Montreal, 1560 Sherbrooke E, Montreal, QC, Canada, H2L 4M1

Chantal Arguin
MetrioGene Biosciences Inc., 6100 Royalmount Av., Montreal, QC, Canada, H4P 2R2

Pauline Johnson
Department of Microbiology and Immunology, University of British Columbia, Canada

Patrice Hugo
MetrioGene Biosciences Inc., 6100 Royalmount Av., Montreal, QC, Canada, H4P 2R2

ABSTRACT

The protein tyrosine phosphatase CD45 is a highly expressed glycoprotein present on all nucleated cells of hematopoietic origin. To date, all the functions attributed to CD45 are inherently coupled to its phosphatase activity. For instance, the regulation of lymphocyte antigen receptor signaling is mediated through the dephosphorylation, and hence activation, of Src-family kinases by CD45. Moreover, signaling via cytokine receptors is negatively modulated by CD45 by dephosphorylation of Janus kinase family members. Recently, another function for CD45, unrelated to regulation of surface receptor signaling, has been unraveled. Specific engagement of CD45 by monoclonal antibodies at the surface of lymphocytes induced their death, through an alternative caspase-independent pathway. In striking contrast to all other previously reported functions for CD45, its phosphatase activity is completely dispensable for the induction of cell death. This article reviews the current knowledge on the death pathway triggered by CD45 ligation on lymphocytes. In an attempt to better elucidate the mechanism of cell death induction through CD45, we also provide original data regarding the susceptibility of various subsets of immature and mature T and B cells to death induced by CD45 engagement. The physiological significance and therapeutic potential of CD45-induced death are also discussed.