title: Defective T cell development and function in calcineurin A beta -deficient mice.
abstract: The calcium-dependent phosphatase calcineurin and its downstream transcriptional effector nuclear factor of activated T cells (NFAT) are important regulators of inducible gene expression in multiple cell types. In T cells, calcineurin-NFAT signaling represents a critical event for mediating cellular activation and the immune response. The widely used immunosuppressant agents cyclosporin and FK506 are thought to antagonize the immune response by directly inhibiting calcineurin-NFAT signal transduction in lymphocytes. To unequivocally establish the importance of calcineurin signaling as a mediator of the immune response, we deleted the gene encoding the predominant calcineurin isoform expressed in lymphocytes, calcineurin A beta (CnA beta). CnA beta(-/-) mice were viable as adults, but displayed defective T cell development characterized by fewer total CD3 cells and reduced CD4 and CD8 single positive cells. Total peripheral T cell numbers were significantly reduced in CnA beta(-/-) mice and were defective in proliferative capacity and IL-2 production in response to PMA/ionomycin and T cell receptor cross-linking. CnA beta(-/-) mice also were permissive to allogeneic tumor-cell transplantation in vivo, similar to cyclosporin-treated wild-type mice. A mechanism for the compromised immune response is suggested by the observation that CnA beta(-/-) T cells are defective in stimulation-induced NFATc1, NFATc2, and NFATc3 activation. These results establish a critical role for CnA beta signaling in regulating T cell development and activation in vivo.
authors.affiliation: Division of Molecular Cardiovascular Biology, Department of Pediatrics, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA.
authors.forename: Orlando F
authors.initials: OF
authors.lastname: Bueno
authors.forename: Eric B
authors.initials: EB
authors.lastname: Brandt
authors.forename: Marc E
authors.initials: ME
authors.lastname: Rothenberg
authors.forename: Jeffery D
authors.initials: JD
authors.lastname: Molkentin
mesh_terms: D000818:Animals; D019703:Calcineurin / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D003602:Cytotoxicity, Immunologic; D004268:DNA-Binding Proteins / Q000378:metabolism; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000096:biosynthesis; D015759:Ionomycin / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D010954:Plasmacytoma / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D007376:Interleukin-2; D050778:NFATC Transcription Factors; C494005:Nfatc1 protein, mouse; C494007:Nfatc2 protein, mouse; C494009:Nfatc3 protein, mouse; D009687:Nuclear Proteins; D011948:Receptors, Antigen, T-Cell; D014157:Transcription Factors; D015759:Ionomycin; D019703:Calcineurin; D013755:Tetradecanoylphorbol Acetate