title: Normal TCR signal transduction in mice that lack catalytically active PTPN3 protein tyrosine phosphatase.
abstract: PTPN3 (PTPH1) is a cytoskeletal protein tyrosine phosphatase that has been implicated as a negative regulator of early TCR signal transduction and T cell activation. To determine whether PTPN3 functions as a physiological negative regulator of TCR signaling in primary T cells, we generated gene-trapped and gene-targeted mouse strains that lack expression of catalytically active PTPN3. PTPN3 phosphatase-negative mice were born in expected Mendelian ratios and exhibited normal growth and development. Furthermore, numbers and ratios of T cells in primary and secondary lymphoid organs were unaffected by the PTPN3 mutations and there were no signs of spontaneous T cell activation in the mutant mice with increasing age. TCR-induced signal transduction, cytokine production, and proliferation was normal in PTPN3 phosphatase-negative mice. This was observed using both quiescent T cells and recently stimulated T cells where expression of PTPN3 is substantially up-regulated. We conclude, therefore, that the phosphatase activity of PTPN3 is dispensable for negative regulation of TCR signal transduction and T cell activation.
authors.affiliation: Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Bauler
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Hughes
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Arimura
authors.forename: Tomas
authors.initials: T
authors.lastname: Mustelin
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Saunders
authors.forename: Philip D
authors.initials: PD
authors.lastname: King
mesh_terms: D000375:Aging / Q000235:genetics / Q000276:immunology; D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D054589:Protein Tyrosine Phosphatase, Non-Receptor Type 3; D017027:Protein Tyrosine Phosphatases / Q000172:deficiency / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D015854:Up-Regulation / Q000276:immunology
chemical_list: D016207:Cytokines; D011948:Receptors, Antigen, T-Cell; D054589:Protein Tyrosine Phosphatase, Non-Receptor Type 3; D017027:Protein Tyrosine Phosphatases; C516657:Ptpn3 protein, mouse