title: Selective and strain-specific NFAT4 activation by the Toxoplasma gondii polymorphic dense granule protein GRA6.
abstract: Toxoplasma gondii infection results in co-option and subversion of host cellular signaling pathways. This process involves discharge of T. gondii effector molecules from parasite secretory organelles such as rhoptries and dense granules. We report that the T. gondii polymorphic dense granule protein GRA6 regulates activation of the host transcription factor nuclear factor of activated T cells 4 (NFAT4). GRA6 overexpression robustly and selectively activated NFAT4 via calcium modulating ligand (CAMLG). Infection with wild-type (WT) but not GRA6-deficient parasites induced NFAT4 activation. Moreover, GRA6-deficient parasites failed to exhibit full virulence in local infection, and the treatment of WT mice with an NFAT inhibitor mitigated virulence of WT parasites. Notably, NFAT4-deficient mice displayed prolonged survival, decreased recruitment of CD11b(+) Ly6G(+) cells to the site of infection, and impaired expression of chemokines such as Cxcl2 and Ccl2. In addition, infection with type I parasites culminated in significantly higher NFAT4 activation than type II parasites due to a polymorphism in the C terminus of GRA6. Collectively, our data suggest that GRA6-dependent NFAT4 activation is required for T. gondii manipulation of host immune responses to maximize the parasite virulence in a strain-dependent manner.
authors.affiliation: Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan myamamoto@biken.osaka-u.ac.jp.
authors.forename: Ji Su
authors.initials: JS
authors.lastname: Ma
authors.affiliation: Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan.
authors.forename: Miwa
authors.initials: M
authors.lastname: Sasai
authors.affiliation: Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Ohshima
authors.affiliation: Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan.
authors.forename: Youngae
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Bando
authors.affiliation: Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Takeda
authors.affiliation: Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan myamamoto@biken.osaka-u.ac.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamamoto
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins; D015153:Blotting, Western; D005260:Female; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000502:physiology*; D047468:Immunoprecipitation; D008156:Luciferases; D008164:Luminescent Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D050778:NFATC Transcription Factors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology*; D014122:Toxoplasma / Q000378:metabolism / Q000472:pathogenicity*; D014123:Toxoplasmosis / Q000503:physiopathology*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000953:Antigens, Protozoan; D001426:Bacterial Proteins; C490314:Caml protein, mouse; C095047:GRA6 protein, Toxoplasma gondii; D008164:Luminescent Proteins; D050778:NFATC Transcription Factors; D015800:Protozoan Proteins; C054562:yellow fluorescent protein, Bacteria; D008156:Luciferases