title: Involvement of the SHP-1 tyrosine phosphatase in regulation of T cell selection.
abstract: The selection events shaping T cell development in the thymus represent the outcome of TCR-driven intracellular signaling cascades evoked by Ag receptor interaction with cognate ligand. In view of data indicating TCR-evoked thymocyte proliferation to be negatively modulated by the SHP-1 tyrosine phosphatase, a potential role for SHP-1 in regulating selection processes was investigated by analysis of T cell development in H-Y TCR transgenic mice rendered SHP-1 deficient by introduction of the viable motheaten mutation or a dominant negative SHP-1-encoding transgene. Characterization of thymocyte and peripheral T cell populations in H-Y TCR-viable motheaten mice revealed TCR-evoked proliferation as well as the positive and negative selection of H-Y-specific thymocytes to be enhanced in these mice, thus implicating SHP-1 in the negative regulation of each of these processes. T cell selection processes were also augmented in H-Y TCR mice carrying a transgene driving lymphoid-restricted expression of a catalytically inert, dominant-negative form of SHP-1. SHP-1-negative effects on thymocyte TCR signaling were not influenced by co-cross-linking of the CD28 costimulatory and/or CTLA-4 inhibitory receptors and appear, accordingly, to be realized independently of these comodulators. These observations indicate that SHP-1 raises the signaling threshold required for both positive and negative selection and reveal the inhibitory effects of SHP-1 on TCR signaling to be cell autonomous. The demonstrated capacity for SHP-1 to inhibit TCR-evoked proliferation and selection indicate SHP-1 modulatory effects on the magnitude of TCR-generated signal to be a key factor in determining the cellular consequences of TCR-ligand interaction.
authors.affiliation: Department of Immunology, University of Toronto, The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: A K
authors.initials: AK
authors.lastname: Somani
authors.forename: D
authors.initials: D
authors.lastname: Yuen
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: P E
authors.initials: PE
authors.lastname: Love
authors.forename: K A
authors.initials: KA
authors.lastname: Siminovitch
mesh_terms: D000069594:Abatacept; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000502:physiology; D018106:CD28 Antigens / Q000502:physiology; D017252:CD3 Complex / Q000276:immunology; D060908:CTLA-4 Antigen; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology; D006182:H-Y Antigen / Q000235:genetics / Q000276:immunology; D018796:Immunoconjugates; D007166:Immunosuppressive Agents / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D008213:Lymphocyte Activation / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008822:Mice, Transgenic; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000502:physiology*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; D015398:Signal Transduction / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000201:enzymology* / Q000276:immunology / Q000378:metabolism; D019076:Transgenes / Q000276:immunology; D018909:src Homology Domains / Q000235:genetics / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D018106:CD28 Antigens; D017252:CD3 Complex; D060908:CTLA-4 Antigen; C556707:Ctla4 protein, mouse; D006182:H-Y Antigen; D018796:Immunoconjugates; D007166:Immunosuppressive Agents; D047908:Intracellular Signaling Peptides and Proteins; D011948:Receptors, Antigen, T-Cell; D000069594:Abatacept; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases; C516725:Ptpn11 protein, mouse; C509248:Ptpn6 protein, mouse; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases