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Luo Y, Tang JF, Gao FF, Quan JH, Ma CT, Li SJ, Fan YM. NLRP3 regulates CIITA/MHC II axis and interferon-γ-inducible chemokines in Malassezia globosa-infected keratinocytes. Mycoses 2024; 67:e13680. [PMID: 38214420 DOI: 10.1111/myc.13680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/27/2023] [Accepted: 11/19/2023] [Indexed: 01/13/2024]
Abstract
CIITA, a member of NOD-like receptor (NLR) family, is the major MHC II trans-activator and mediator of Th1 immunity, but its function and interaction with NLRP3 have been little studied. We found activation of NLRP3 inflammasome, increased expression of CIITA, CBP, pSTAT1, STAT1, MHC II, IFN-γ and IFN-γ-inducible chemokines (CCL1 and CXCL8), and colocalisation of NLRP3 with CIITA in Malassezia folliculitis lesions, Malassezia globosa-infected HaCaT cells and mouse skin. CoIP with anti-CIITA or anti-NLRP3 antibody pulled down NLRP3 or both CIITA and ASC. NLRP3 silencing or knockout caused CIITA downexpression and their colocalisation disappearance in HaCaT cells and mouse skin of Nlrp3-/- mice, while CIITA knockdown had no effect on NLRP3, ASC, IL-1β and IL-18 expression. NLRP3 inflammasome inhibitors and knockdown significantly suppressed IFN-γ, CCL1, CXCL8 and CXCL10 levels in M. globosa-infected HaCaT cells. CCL1 and CXCL8 expression was elevated in Malassezia folliculitis lesions and reduced in Nlrp3-/- mice. These results demonstrate that M. globosa can activate NLRP3 inflammasome, CIITA/MHC II signalling and IFN-γ-inducible chemokines in human keratinocytes and mouse skin. NLRP3 may regulate CIITA by their binding and trigger Th1 immunity by secreting CCL1 and CXCL8/IL-8, contributing to the pathogenesis of Malassezia-associated skin diseases.
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Affiliation(s)
- Yun Luo
- Department of Dermatology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Jin-Feng Tang
- Department of Dermatology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Fei-Fei Gao
- Stem Cell Research and Cellular Therapy Center, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Juan-Hua Quan
- Department of Gastroenterology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Chuan-Ting Ma
- Department of Dermatology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Shi-Jie Li
- Department of Dermatology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Yi-Ming Fan
- Department of Dermatology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
- Dermatology, Plastic and Cosmetic Surgery Center, First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, China
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2
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Wu X, Yang ZH, Wu J, Han J. Ribosome-rescuer PELO catalyzes the oligomeric assembly of NOD-like receptor family proteins via activating their ATPase enzymatic activity. Immunity 2023; 56:926-943.e7. [PMID: 36948192 DOI: 10.1016/j.immuni.2023.02.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/17/2022] [Accepted: 02/22/2023] [Indexed: 03/24/2023]
Abstract
NOD-like receptors (NLRs) are pattern recognition receptors for diverse innate immune responses. Self-oligomerization after engagement with a ligand is a generally accepted model for the activation of each NLR. We report here that a catalyzer was required for NLR self-oligomerization. PELO, a well-known surveillance factor in translational quality control and/or ribosome rescue, interacted with all cytosolic NLRs and activated their ATPase activity. In the case of flagellin-initiated NLRC4 inflammasome activation, flagellin-bound NAIP5 recruited the first NLRC4 and then PELO was required for correctly assembling the rest of NLRC4s into the NLRC4 complex, one by one, by activating the NLRC4 ATPase activity. Stoichiometric and functional data revealed that PELO was not a structural constituent of the NLRC4 inflammasome but a powerful catalyzer for its assembly. The catalytic role of PELO in the activation of cytosolic NLRs provides insight into NLR activation and provides a direction for future studies of NLR family members.
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Affiliation(s)
- Xiurong Wu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China.
| | - Zhang-Hua Yang
- Research Unit of Cellular Stress of CAMS, Xiang'an Hospital of Xiamen University, Cancer Research Center of Xiamen University, School of Medicine, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Jianfeng Wu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China; Laboratory Animal Center, Xiamen University, Xiamen, Fujian 361102, China
| | - Jiahuai Han
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China; Research Unit of Cellular Stress of CAMS, Xiang'an Hospital of Xiamen University, Cancer Research Center of Xiamen University, School of Medicine, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China; Laboratory Animal Center, Xiamen University, Xiamen, Fujian 361102, China.
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3
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Bruchez A, Sha K, Johnson J, Chen L, Stefani C, McConnell H, Gaucherand L, Prins R, Matreyek KA, Hume AJ, Mühlberger E, Schmidt EV, Olinger GG, Stuart LM, Lacy-Hulbert A. MHC class II transactivator CIITA induces cell resistance to Ebola virus and SARS-like coronaviruses. Science 2020; 370:241-247. [PMID: 32855215 PMCID: PMC7665841 DOI: 10.1126/science.abb3753] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 08/20/2020] [Indexed: 01/01/2023]
Abstract
Recent outbreaks of Ebola virus (EBOV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have exposed our limited therapeutic options for such diseases and our poor understanding of the cellular mechanisms that block viral infections. Using a transposon-mediated gene-activation screen in human cells, we identify that the major histocompatibility complex (MHC) class II transactivator (CIITA) has antiviral activity against EBOV. CIITA induces resistance by activating expression of the p41 isoform of invariant chain CD74, which inhibits viral entry by blocking cathepsin-mediated processing of the Ebola glycoprotein. We further show that CD74 p41 can block the endosomal entry pathway of coronaviruses, including SARS-CoV-2. These data therefore implicate CIITA and CD74 in host defense against a range of viruses, and they identify an additional function of these proteins beyond their canonical roles in antigen presentation.
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MESH Headings
- Antigens, Differentiation, B-Lymphocyte/genetics
- Antigens, Differentiation, B-Lymphocyte/physiology
- Betacoronavirus/physiology
- COVID-19
- Cell Line, Tumor
- Coronavirus Infections/immunology
- Coronavirus Infections/virology
- DNA Transposable Elements
- Ebolavirus/physiology
- Endosomes/virology
- Genetic Testing
- Hemorrhagic Fever, Ebola/immunology
- Hemorrhagic Fever, Ebola/virology
- Histocompatibility Antigens Class II/genetics
- Histocompatibility Antigens Class II/physiology
- Host-Pathogen Interactions/genetics
- Host-Pathogen Interactions/immunology
- Humans
- Nuclear Proteins/genetics
- Nuclear Proteins/physiology
- Pandemics
- Pneumonia, Viral/immunology
- Pneumonia, Viral/virology
- SARS-CoV-2
- Trans-Activators/genetics
- Trans-Activators/physiology
- Transcription, Genetic
- Virus Internalization
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Affiliation(s)
- Anna Bruchez
- Benaroya Research Institute, Seattle, WA 98101, USA
| | - Ky Sha
- Benaroya Research Institute, Seattle, WA 98101, USA
| | - Joshua Johnson
- National Institute of Allergy and Infectious Diseases (NIAID) Integrated Research Facility, Frederick, MD 21702, USA
| | - Li Chen
- Massachusetts General Hospital, Boston, MA 02114, USA
| | | | | | | | - Rachel Prins
- Benaroya Research Institute, Seattle, WA 98101, USA
| | - Kenneth A Matreyek
- Department of Genome Sciences, University of Washington, Seattle, WA 98109, USA
| | - Adam J Hume
- Boston University School of Medicine, Boston, MA 02118, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA 02118, USA
| | - Elke Mühlberger
- Boston University School of Medicine, Boston, MA 02118, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA 02118, USA
| | | | - Gene G Olinger
- National Institute of Allergy and Infectious Diseases (NIAID) Integrated Research Facility, Frederick, MD 21702, USA
- Boston University School of Medicine, Boston, MA 02118, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA 02118, USA
- MRIGlobal, Gaithersburg, MD 20878, USA
| | - Lynda M Stuart
- Benaroya Research Institute, Seattle, WA 98101, USA
- Bill and Melinda Gates Foundation, Seattle, WA 98109, USA
| | - Adam Lacy-Hulbert
- Benaroya Research Institute, Seattle, WA 98101, USA.
- Department of Immunology, University of Washington, Seattle, WA 98109, USA
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4
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Development of potent class II transactivator gene delivery systems capable of inducing de novo MHC II expression in human cells, in vitro and ex vivo. Gene Ther 2017; 24:342-352. [PMID: 28414303 DOI: 10.1038/gt.2017.25] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 02/01/2017] [Accepted: 02/06/2017] [Indexed: 01/17/2023]
Abstract
Class II transactivator (CIITA) induces transcription of major histocompatibility complex (MHC) II genes and can potentially be used to improve genetic immunotherapies by converting non-immune cells into cells capable of presenting antigens to CD4+ T cells. However, CIITA expression is tightly controlled and it remains unclear whether distinct non-immune cells differ in this transactivator regulation. Here we describe the development of gene delivery systems capable of promoting the efficient CIITA expression in non-immune cell lines and in primary human cells of an ex vivo skin explant model. Different human cell types undergoing CIITA overexpression presented high-level de novo expression of MHC II, validating the delivery systems as suitable tools for the CIITA evaluation as a molecular adjuvant for gene therapies.
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5
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Jardin F, Pujals A, Pelletier L, Bohers E, Camus V, Mareschal S, Dubois S, Sola B, Ochmann M, Lemonnier F, Viailly PJ, Bertrand P, Maingonnat C, Traverse-Glehen A, Gaulard P, Damotte D, Delarue R, Haioun C, Argueta C, Landesman Y, Salles G, Jais JP, Figeac M, Copie-Bergman C, Molina TJ, Picquenot JM, Cornic M, Fest T, Milpied N, Lemasle E, Stamatoullas A, Moeller P, Dyer MJS, Sundstrom C, Bastard C, Tilly H, Leroy K. Recurrent mutations of the exportin 1 gene (XPO1) and their impact on selective inhibitor of nuclear export compounds sensitivity in primary mediastinal B-cell lymphoma. Am J Hematol 2016; 91:923-30. [PMID: 27312795 DOI: 10.1002/ajh.24451] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 06/11/2016] [Accepted: 06/14/2016] [Indexed: 02/01/2023]
Abstract
Primary mediastinal B-cell lymphoma (PMBL) is an entity of B-cell lymphoma distinct from the other molecular subtypes of diffuse large B-cell lymphoma (DLBCL). We investigated the prevalence, specificity, and clinical relevance of mutations of XPO1, which encodes a member of the karyopherin-β nuclear transporters, in a large cohort of PMBL. PMBL cases defined histologically or by gene expression profiling (GEP) were sequenced and the XPO1 mutational status was correlated to genetic and clinical characteristics. The XPO1 mutational status was also assessed in DLBCL, Hodgkin lymphoma (HL) and mediastinal gray-zone lymphoma (MGZL).The biological impact of the mutation on Selective Inhibitor of Nuclear Export (SINE) compounds (KPT-185/330) sensitivity was investigated in vitro. XPO1 mutations were present in 28/117 (24%) PMBL cases and in 5/19 (26%) HL cases but absent/rare in MGZL (0/20) or DLBCL (3/197). A higher prevalence (50%) of the recurrent codon 571 variant (p.E571K) was observed in GEP-defined PMBL and was associated with shorter PFS. Age, International Prognostic Index and bulky mass were similar in XPO1 mutant and wild-type cases. KPT-185 induced a dose-dependent decrease in cell proliferation and increased cell-death in PMBL cell lines harboring wild type or XPO1 E571K mutant alleles. Experiments in transfected U2OS cells further confirmed that the XPO1 E571K mutation does not have a drastic impact on KPT-330 binding. To conclude the XPO1 E571K mutation represents a genetic hallmark of the PMBL subtype and serves as a new relevant PMBL biomarker. SINE compounds appear active for both mutated and wild-type protein. Am. J. Hematol. 91:923-930, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Fabrice Jardin
- Departement of Hematology, Inserm U918, Centre Henri Becquerel, Rouen, France
| | - Anais Pujals
- Departement of Hematology, Inserm U955 Team 09, APHP Hospital Henri Mondor, Créteil, France
| | - Laura Pelletier
- Departement of Hematology, Inserm U955 Team 09, APHP Hospital Henri Mondor, Créteil, France
| | - Elodie Bohers
- Departement of Hematology, Inserm U918, Centre Henri Becquerel, Rouen, France
| | - Vincent Camus
- Departement of Hematology, Inserm U918, Centre Henri Becquerel, Rouen, France
| | - Sylvain Mareschal
- Departement of Hematology, Inserm U918, Centre Henri Becquerel, Rouen, France
| | - Sydney Dubois
- Departement of Hematology, Inserm U918, Centre Henri Becquerel, Rouen, France
| | - Brigitte Sola
- Departement of Hematology, Normandie Univ, UNICAEN, Caen, EA4652, France
| | - Marlène Ochmann
- Departement of Hematology, Inserm U917, CHU Pontchaillou, Rennes, France
| | - François Lemonnier
- Departement of Hematology, Inserm U955 Team 09, APHP Hospital Henri Mondor, Créteil, France
| | | | - Philippe Bertrand
- Departement of Hematology, Inserm U918, Centre Henri Becquerel, Rouen, France
| | | | | | - Philippe Gaulard
- Departement of Hematology, Inserm U955 Team 09, APHP Hospital Henri Mondor, Créteil, France
| | - Diane Damotte
- Departement of Hematology, Hospices Civils De Lyon, Lyon-1 University, Pierre Benite, CNRS UMR5239, France
| | - Richard Delarue
- Department of Pathology, Hôpitaux Universitaires, Paris Centre, Team « Cancer, Immune Control, and Escape » INSERM U1138, Cordeliers Research Center, Paris, France
| | - Corinne Haioun
- Departement of Hematology, Inserm U955 Team 09, APHP Hospital Henri Mondor, Créteil, France
| | | | - Yosef Landesman
- Department of Hematology, Necker Hospital, AP-HP, Paris, France
| | | | | | - Martin Figeac
- Departement of Genomics, Functional Genomic Platforms, IRCL, Lille, France
| | | | | | | | - Marie Cornic
- Departement of Hematology, Inserm U918, Centre Henri Becquerel, Rouen, France
| | - Thierry Fest
- Departement of Hematology, Inserm U917, CHU Pontchaillou, Rennes, France
| | - Noel Milpied
- Department of Hematology, CHU De Bordeaux, France
| | - Emilie Lemasle
- Departement of Hematology, Inserm U918, Centre Henri Becquerel, Rouen, France
| | | | - Peter Moeller
- Department of Pathology, Institute of Pathology, University of Ulm, Germany
| | - Martin J S Dyer
- Department of Hematology, Ernest and Helen Scott Haematological Research Institute, University of Leicester, Leicester, United Kingdom
| | | | - Christian Bastard
- Departement of Hematology, Inserm U918, Centre Henri Becquerel, Rouen, France
| | - Hervé Tilly
- Departement of Hematology, Inserm U918, Centre Henri Becquerel, Rouen, France
| | - Karen Leroy
- Departement of Hematology, Inserm U955 Team 09, APHP Hospital Henri Mondor, Créteil, France
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6
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Downs I, Vijayan S, Sidiq T, Kobayashi KS. CITA/NLRC5: A critical transcriptional regulator of MHC class I gene expression. Biofactors 2016; 42:349-57. [PMID: 27087581 DOI: 10.1002/biof.1285] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 03/07/2016] [Accepted: 03/09/2016] [Indexed: 01/01/2023]
Abstract
Major histocompatibility complex (MHC) class I and class II molecules play essential roles in the development and activation of the human adaptive immune system. An NLR protein, CIITA (MHC class II transactivator) has been recognized as a master regulator of MHC class II gene expression, albeit knowledge about the regulatory mechanism of MHC class I gene expression had been limited. Recently identified MHC class I transactivator (CITA), or NLRC5, also belongs to the NLR protein family and constitutes a critical regulator for the transcriptional activation of MHC class I genes. In addition to MHC class I genes, CITA/NLRC5 induces the expression of β2 -microglobulin, TAP1 and LMP2, essential components of the MHC class I antigen presentation pathway. Therefore, CITA/NLRC5 and CIITA are transcriptional regulators that orchestrate the concerted expression of critical components in the MHC class I and class II pathways, respectively. © 2016 BioFactors, 42(4):349-357, 2016.
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Affiliation(s)
- Isaac Downs
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX
| | - Saptha Vijayan
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX
| | - Tabasum Sidiq
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX
| | - Koichi S Kobayashi
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, TX
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7
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Xu Z, Cheng K, Li X, Yang J, Xu S, Cao X, Hu X, Xie W, Yuan L, Ambrose M, Chen G, Mi H, Luo D. Transcriptional and Post-transcriptional Modulation of SQU and KEW Activities in the Control of Dorsal-Ventral Asymmetric Flower Development in Lotus japonicus. MOLECULAR PLANT 2016; 9:722-736. [PMID: 26854849 DOI: 10.1016/j.molp.2016.01.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 01/16/2016] [Accepted: 01/30/2016] [Indexed: 06/05/2023]
Abstract
In Papilionoideae legume, Lotus japonicus, the development of dorsal-ventral (DV) asymmetric flowers is mainly controlled by two TB1/CYCLOIDEA/PCF (TCP) genes, SQUARED STANDARD (SQU) and KEELED WINGS IN LOTUS (KEW), which determine dorsal and lateral identities, respectively. However, the molecular basis of how these two highly homologous genes orchestrate their diverse functions remains unclear. Here, we analyzed their expression levels, and investigated the transcriptional activities of SQU and KEW. We demonstrated that SQU possesses both activation and repression activities, while KEW acts only as an activator. They form homo- and heterodimers, and then collaboratively regulate their expression at the transcription level. Furthermore, we identified two types of post-transcriptional modifications, phosphorylation and ATP/GTP binding, both of which could affect their transcriptional activities. Mutations in ATP/GTP binding motifs of SQU and KEW lead to failure of phosphorylation, and transgenic plants bearing the mutant proteins display defective DV asymmetric flower development, indicating that the two conjugate modifications are essential for their diverse functions. Altogether, SQU and KEW activities are precisely modulated at both transcription and post-transcription levels, which might link DV asymmetric flower development to different physiological status and/or signaling pathways.
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Affiliation(s)
- Zhiyong Xu
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China; National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Modality of LFIA, Research and Application Marketing, Healthcare Group of General Electric, China Technology Park, Shanghai 201203, China
| | - Kai Cheng
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Xin Li
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jun Yang
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Shilei Xu
- Laboratory of Cancer Cell Biology, Tianjin Medical University Cancer Hospital and Institute, Tianjin 300060, China
| | - Xiangling Cao
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xiaohe Hu
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Wei Xie
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Ling Yuan
- Department of Plant and Soil Sciences, Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, KY 40546, USA
| | - Mike Ambrose
- Department of Crop Genetics, John Innes Centre, Colney, Norwich NR4 7UH, UK
| | - Genyun Chen
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Hualing Mi
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Da Luo
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
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8
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The Major Histocompatibility Complex Class II Transactivator CIITA Inhibits the Persistent Activation of NF-κB by the Human T Cell Lymphotropic Virus Type 1 Tax-1 Oncoprotein. J Virol 2016; 90:3708-21. [PMID: 26792751 DOI: 10.1128/jvi.03000-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 01/18/2016] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED Human T cell lymphotropic virus type 1 (HTLV-1) Tax-1, a key protein in HTLV-1-induced T cell transformation, deregulates diverse cell signaling pathways. Among them, the NF-κB pathway is constitutively activated by Tax-1, which binds to NF-κB proteins and activates the IκB kinase (IKK). Upon phosphorylation-dependent IκB degradation, NF-κB migrates into the nucleus, mediating Tax-1-stimulated gene expression. We show that the transcriptional regulator of major histocompatibility complex class II genes CIITA (class II transactivator), endogenously or ectopically expressed in different cells, inhibits the activation of the canonical NF-κB pathway by Tax-1 and map the region that mediates this effect. CIITA affects the subcellular localization of Tax-1, which is mostly retained in the cytoplasm, and this correlates with impaired migration of RelA into the nucleus. Cytoplasmic and nuclear mutant forms of CIITA reveal that CIITA exploits different strategies to suppress Tax-1-mediated NF-κB activation in both subcellular compartments. CIITA interacts with Tax-1 without preventing Tax-1 binding to both IKKγ and RelA. Nevertheless, CIITA affects Tax-1-induced IKK activity, causing retention of the inactive p50/RelA/IκB complex in the cytoplasm. Nuclear CIITA associates with Tax-1/RelA in nuclear bodies, blocking Tax-1-dependent activation of NF-κB-responsive genes. Thus, CIITA inhibits cytoplasmic and nuclear steps of Tax-1-mediated NF-κB activation. These results, together with our previous finding that CIITA acts as a restriction factor inhibiting Tax-1-promoted HTLV-1 gene expression and replication, indicate that CIITA is a versatile molecule that might also counteract Tax-1 transforming activity. Unveiling the molecular basis of CIITA-mediated inhibition of Tax-1 functions may be important in defining new strategies to control HTLV-1 spreading and oncogenic potential. IMPORTANCE HTLV-1 is the causative agent of human adult T cell leukemia-lymphoma (ATLL). The viral transactivator Tax-1 plays a central role in the onset of ATLL, mostly by deregulating the NF-κB pathway. We demonstrate that CIITA, a key regulator of adaptive immunity, suppresses Tax-1-dependent activation of NF-κB by acting at several levels: it retains most of Tax-1 and RelA in the cytoplasm and inhibits their residual functional activity in the nucleus. Importantly, this inhibition occurs in cells that are targets of HTLV-1 infection. These findings are of interest in the field of virology because they expand the current knowledge of the functional relationship between viral products and cellular interactors and provide the basis for a better understanding of the molecular countermeasures adopted by the host cell to antagonize HTLV-1 spreading and transforming properties. Within this framework, our results may contribute to the establishment of novel strategies against HTLV-1 infection and virus-dependent oncogenic transformation.
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9
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Chiu E, Gold T, Fettig V, LeVasseur MT, Cressman DE. Identification of a nuclear export sequence in the MHC CIITA. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 194:6102-11. [PMID: 25948812 DOI: 10.4049/jimmunol.1402026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 04/02/2015] [Indexed: 01/15/2023]
Abstract
Initiation of an immune response through expression of MHC class II and related genes is under the control of the CIITA. Normally found in both the cytoplasm and nucleus, CIITA is tightly controlled by a variety of posttranslational modifications as well as interactions with other nuclear and cytoplasmic factors, whereas disruption of this dual subcellular localization impairs CIITA functioning and expression of target genes. Although CIITA has well-defined domains necessary for its nuclear import, the region responsible for the translocation of CIITA from the nucleus has not been characterized. In this study, we identify a leucine-rich motif at residues 717-724 that bears strong homology to known nuclear export sequence (NES) domains. Mutation of this region renders CIITA insensitive to treatment with leptomycin B, an inhibitor of nuclear export, whereas fusion of this domain to a heterologous GFP is sufficient to induce its export to the cytoplasm or cause its retention in the nucleus following leptomycin B treatment. Point mutations of specific leucine residues within the NES disrupt the normal subcellular distribution of the full-length CIITA, impair its ability to interact with the nuclear export factor CRM1, and enhance CIITA-induced gene expression from an MHC class II gene promoter. IFN-γ stimulation of class II genes is further enhanced by inhibiting the nuclear export of endogenous CIITA. Collectively, these data demonstrate the first identification of a specific NES within CIITA and place it among the other protein domains that contribute to the posttranslational regulation of CIITA activity.
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Affiliation(s)
- Emily Chiu
- Department of Biology, Sarah Lawrence College, Bronxville, NY 10708
| | - Theresa Gold
- Department of Biology, Sarah Lawrence College, Bronxville, NY 10708
| | - Veronica Fettig
- Department of Biology, Sarah Lawrence College, Bronxville, NY 10708
| | | | - Drew E Cressman
- Department of Biology, Sarah Lawrence College, Bronxville, NY 10708
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10
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Devaiah BN, Singer DS. CIITA and Its Dual Roles in MHC Gene Transcription. Front Immunol 2013; 4:476. [PMID: 24391648 PMCID: PMC3868913 DOI: 10.3389/fimmu.2013.00476] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 12/07/2013] [Indexed: 01/07/2023] Open
Abstract
Class II transactivator (CIITA) is a transcriptional coactivator that regulates γ-interferon-activated transcription of Major Histocompatibility Complex (MHC) class I and II genes. As such, it plays a critical role in immune responses: CIITA deficiency results in aberrant MHC gene expression and consequently in autoimmune diseases such as Type II bare lymphocyte syndrome. Although CIITA does not bind DNA directly, it regulates MHC transcription in two distinct ways - as a transcriptional activator and as a general transcription factor. As an activator, CIITA nucleates an enhanceosome consisting of the DNA binding transcription factors RFX, cyclic AMP response element binding protein, and NF-Y. As a general transcription factor, CIITA functionally replaces the TFIID component, TAF1. Like TAF1, CIITA possesses acetyltransferase (AT) and kinase activities, both of which contribute to proper transcription of MHC class I and II genes. The substrate specificity and regulation of the CIITA AT and kinase activities also parallel those of TAF1. In addition, CIITA is tightly regulated by its various regulatory domains that undergo phosphorylation and influence its targeted localization. Thus, a complex picture of the mechanisms regulating CIITA function is emerging suggesting that CIITA has dual roles in transcriptional regulation which are summarized in this review.
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Affiliation(s)
| | - Dinah S Singer
- Experimental Immunology Branch, National Cancer Institute, NIH , Bethesda, MD , USA
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11
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Zhong Y, Kinio A, Saleh M. Functions of NOD-Like Receptors in Human Diseases. Front Immunol 2013; 4:333. [PMID: 24137163 PMCID: PMC3797414 DOI: 10.3389/fimmu.2013.00333] [Citation(s) in RCA: 210] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 10/02/2013] [Indexed: 12/26/2022] Open
Abstract
Nucleotide-binding and oligomerization domain NOD-like receptors (NLRs) are highly conserved cytosolic pattern recognition receptors that perform critical functions in surveying the intracellular environment for the presence of infection, noxious substances, and metabolic perturbations. Sensing of these danger signals by NLRs leads to their oligomerization into large macromolecular scaffolds and the rapid deployment of effector signaling cascades to restore homeostasis. While some NLRs operate by recruiting and activating inflammatory caspases into inflammasomes, others trigger inflammation via alternative routes including the nuclear factor-κB, mitogen-activated protein kinase, and regulatory factor pathways. The critical role of NLRs in development and physiology is demonstrated by their clear implications in human diseases. Mutations in the genes encoding NLRP3 or NLRP12 lead to hereditary periodic fever syndromes, while mutations in CARD15 that encodes NOD2 are linked to Crohn’s disease or Blau’s syndrome. Genome-wide association studies (GWASs) have identified a number of risk alleles encompassing NLR genes in a host of diseases including allergic rhinitis, multiple sclerosis, inflammatory bowel disease, asthma, multi-bacillary leprosy, vitiligo, early-onset menopause, and bone density loss in elderly women. Animal models have allowed the characterization of underlying effector mechanisms in a number of cases. In this review, we highlight the functions of NLRs in health and disease and discuss how the characterization of their molecular mechanisms provides new insights into therapeutic strategies for the management of inflammatory pathologies.
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Affiliation(s)
- Yifei Zhong
- Department of Microbiology and Immunology, McGill University , Montreal, QC , Canada
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12
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Soe KC, Devaiah BN, Singer DS. Transcriptional coactivator CIITA, a functional homolog of TAF1, has kinase activity. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1829:1184-90. [PMID: 24036077 DOI: 10.1016/j.bbagrm.2013.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 09/03/2013] [Accepted: 09/04/2013] [Indexed: 11/26/2022]
Abstract
The Major Histocompatibility Complex (MHC) class II transactivator (CIITA) mediates activated immune responses and its deficiency results in the Type II Bare Lymphocyte Syndrome. CIITA is a transcriptional co-activator that regulates γ-interferon-activated transcription of MHC class I and class II genes. It is also a functional homolog of TAF1, a component of the general transcription factor complex TFIID. TAF1 and CIITA both possess intrinsic acetyltransferase (AT) activity that is required for transcription initiation. In response to induction by γ-interferon, CIITA and it's AT activity bypass the requirement for TAF1 AT activity. TAF1 also has kinase activity that is essential for its function. However, no similar activity has been identified for CIITA thus far. Here we report that CIITA, like TAF1, is a serine-threonine kinase. Its substrate specificity parallels, but does not duplicate, that of TAF1 in phosphorylating the TFIID component TAF7, the RAP74 subunit of the general transcription factor TFIIF and histone H2B. Like TAF1, CIITA autophosphorylates, affecting its interaction with TAF7. Additionally, CIITA phosphorylates histone H2B at Ser36, a target of TAF1 that is required for transcription during cell cycle progression and stress response. However, unlike TAF1, CIITA also phosphorylates all the other histones. The identification of this novel kinase activity of CIITA further clarifies its role as a functional homolog of TAF1 which may operate during stress and γ-IFN activated MHC gene transcription.
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Affiliation(s)
- Katherine C Soe
- Experimental Immunology Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA
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13
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Robbins GR, Truax AD, Davis BK, Zhang L, Brickey WJ, Ting JPY. Regulation of class I major histocompatibility complex (MHC) by nucleotide-binding domain, leucine-rich repeat-containing (NLR) proteins. J Biol Chem 2012; 287:24294-303. [PMID: 22645137 DOI: 10.1074/jbc.m112.364604] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Most of the nucleotide-binding domain, leucine-rich repeat (NLR) proteins regulate responses to microbial and damage-associated products. Class II transactivator (CIITA) has a distinct function as the master regulator of class II major histocompatibility complex (MHC-II) transcription. Recently, human NLRC5 was found to regulate MHC-I in cell lines; however, a host of conflicting positive and negative functions has been attributed to this protein. To address the function of NLRC5 in a physiologic setting, we generated an Nlrc5(-/-) strain that contains a deletion in the exon that encodes the nucleotide-binding domain. We have not detected a role for this protein in cytokine induction by pathogen-associated molecular patterns and viruses. However, Nlrc5(-/-) cells showed a dramatic decrease of classical (H-2K) and nonclassical (Tla) MHC-I expression by T/B lymphocytes, natural killer (NK) cells, and myeloid-monocytic lineages. As a comparison, CIITA did not affect mouse MHC-I expression. Nlrc5(-/-) splenocytes and bone marrow-derived macrophages were able to up-regulate MHC-I in response to IFN-γ; however, the absolute levels of MHC-I expression were significantly lower than WT controls. Chromatin immunoprecipitation of IFN-γ-treated cells indicates that Nlrc5 reduced the silencing H3K27me3 histone modification, but did not affect the activating AcH3 modification on a MHC-I promoter. In summary, we conclude that Nlrc5 is important in the regulation of MHC-I expression by reducing H3K27me3 on MHC-I promoter and joins CIITA as an NLR subfamily that controls MHC gene transcription.
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Affiliation(s)
- Gregory R Robbins
- Department of Microbiology and Immunology, Lineberger Comprehensive Cancer Center, the Institute of Inflammatory Diseases and Center of Translational Immunology, University of North Carolina, Chapel Hill, North Carolina 27599-7295, USA
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14
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Meissner TB, Li A, Kobayashi KS. NLRC5: a newly discovered MHC class I transactivator (CITA). Microbes Infect 2011; 14:477-84. [PMID: 22209772 DOI: 10.1016/j.micinf.2011.12.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 12/09/2011] [Accepted: 12/12/2011] [Indexed: 02/07/2023]
Abstract
Major histocompatibility complex (MHC) class I and class II are crucial for the function of the human adaptive immune system. An NLR protein, CIITA (MHC class II transactivator), is a master regulator of MHC class II gene expression as well as of some of the genes involved in MHC class II antigen presentation. It has recently been discovered that another member of the NLR protein family, NLRC5, transcriptionally activates MHC class I genes, and thus acts as "CITA" (MHC class I transactivator), a counterpart to CIITA. In addition to MHC class I genes, NLRC5 can induce the expression of β2M, TAP1 and LMP2, essential components of MHC class I antigen presentation. These findings indicate that NLRC5 and CIITA are transcriptional regulators that orchestrate the concerted expression of critical components in the MHC class I and MHC class II pathways, respectively.
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Affiliation(s)
- Torsten B Meissner
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Dana 1420A, Boston, MA 02215, United States
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15
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Lee N, Iyer SS, Mu J, Weissman JD, Ohali A, Howcroft TK, Lewis BA, Singer DS. Three novel downstream promoter elements regulate MHC class I promoter activity in mammalian cells. PLoS One 2010; 5:e15278. [PMID: 21179443 PMCID: PMC3001478 DOI: 10.1371/journal.pone.0015278] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 11/09/2010] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND MHC CLASS I TRANSCRIPTION IS REGULATED BY TWO DISTINCT TYPES OF REGULATORY PATHWAYS: 1) tissue-specific pathways that establish constitutive levels of expression within a given tissue and 2) dynamically modulated pathways that increase or decrease expression within that tissue in response to hormonal or cytokine mediated stimuli. These sets of pathways target distinct upstream regulatory elements, have distinct basal transcription factor requirements, and utilize discrete sets of transcription start sites within an extended core promoter. METHODOLOGY/PRINCIPAL FINDINGS We studied regulatory elements within the MHC class I promoter by cellular transfection and in vitro transcription assays in HeLa, HeLa/CIITA, and tsBN462 of various promoter constructs. We have identified three novel MHC class I regulatory elements (GLE, DPE-L1 and DPE-L2), located downstream of the major transcription start sites, that contribute to the regulation of both constitutive and activated MHC class I expression. These elements located at the 3' end of the core promoter preferentially regulate the multiple transcription start sites clustered at the 5' end of the core promoter. CONCLUSIONS/SIGNIFICANCE Three novel downstream elements (GLE, DPE-L1, DPE-L2), located between +1 and +32 bp, regulate both constitutive and activated MHC class I gene expression by selectively increasing usage of transcription start sites clustered at the 5' end of the core promoter upstream of +1 bp. Results indicate that the downstream elements preferentially regulate TAF1-dependent, relative to TAF1-independent, transcription.
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Affiliation(s)
- Namhoon Lee
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- Cellular, Molecular, Developmental Biology and Biophysics, NIH-Johns Hopkins University, Bethesda, Maryland, United States of America
| | - Shankar S. Iyer
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, United States of America
| | - Jie Mu
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jocelyn D. Weissman
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Anat Ohali
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - T. Kevin Howcroft
- Division of Cancer Biology, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Brian A. Lewis
- Metabolism Branch, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Dinah S. Singer
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- Metabolism Branch, National Cancer Institute, Bethesda, Maryland, United States of America
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16
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17
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Voong LN, Slater AR, Kratovac S, Cressman DE. Mitogen-activated protein kinase ERK1/2 regulates the class II transactivator. J Biol Chem 2008; 283:9031-9. [PMID: 18245089 PMCID: PMC2431044 DOI: 10.1074/jbc.m706487200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Revised: 01/31/2008] [Indexed: 01/12/2023] Open
Abstract
The expression of major histocompatibility class II genes is necessary for proper antigen presentation and induction of an immune response. This expression is initiated by the class II transactivator, CIITA. The establishment of the active form of CIITA is controlled by a series of post-translational events, including GTP binding, ubiquitination, and dimerization. However, the role of phosphorylation is less clearly defined as are the consequences of phosphorylation on CIITA activity and the identity of the kinases involved. In this study we show that the extracellular signal-regulated kinases 1 and 2 (ERK1/2) interact directly with CIITA, targeting serine residues in the amino terminus of the protein, including serine 288. Inhibition of this phosphorylation by dominant-negative forms of ERK or by treatment of cells with the ERK inhibitor PD98059 resulted in the increase in CIITA-mediated gene expression from a class II promoter, enhanced the nuclear concentration of CIITA, and impaired its ability to bind to the nuclear export factor, CRM1. In contrast, inhibition of ERK1/2 activity had little effect on serine-to-alanine mutant forms of CIITA. These data suggest a model whereby ERK1/2-mediated phosphorylation of CIITA down-regulates CIITA activity by priming it for nuclear export, thus providing a means for cells to tightly regulate the extent of antigen presentation.
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Affiliation(s)
- Lilien N Voong
- Department of Biology, Sarah Lawrence College, 1 Mead Way, Bronxville, NY 10708, USA
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18
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Bewry NN, Bolick SCE, Wright KL, Harton JA. GTP-dependent recruitment of CIITA to the class II major histocompatibility complex promoter. J Biol Chem 2007; 282:26178-84. [PMID: 17623662 DOI: 10.1074/jbc.m611747200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We previously established that the class II transactivator CIITA binds GTP and disruption of the GTP binding ability of CIITA results in increased cytoplasmic CIITA, loss of nuclear CIITA, and thus diminished class II major histocompatibility complex transcription. Because of its role in facilitating nuclear localization, whether GTP binding is also required for CIITA-mediated transactivation of major histocompatibility class II genes remains unclear. We now show that recruitment of CIITA to the human leukocyte antigen (HLA)-DR promoter and activation of HLA-DR transcription is also GTP-dependent. After restoration of nuclear expression, CIITA mutants defective in GTP binding lack full transcriptional activation capacity. Although the availability of the activation domain of CIITA is unaltered, GTP mutants no longer cooperate with CREB-binding protein, p300, and pCAF and are defective in recruitment to the HLA-DR promoter.
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Affiliation(s)
- Nadine N Bewry
- Department of Molecular Medicine, H. Lee Moffitt Cancer Center, University of South Florida, Tampa, Florida 33612, USA
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19
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Tosi G, Pilotti E, Mortara L, Barbaro ADL, Casoli C, Accolla RS. Inhibition of human T cell leukemia virus type 2 replication by the suppressive action of class II transactivator and nuclear factor Y. Proc Natl Acad Sci U S A 2006; 103:12861-6. [PMID: 16908858 PMCID: PMC1568938 DOI: 10.1073/pnas.0601589103] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2006] [Indexed: 11/18/2022] Open
Abstract
The master regulator of MHC-II gene transcription, class II transactivator (CIITA), acts as a potent inhibitor of human T cell leukemia virus type 2 (HTLV-2) replication by blocking the activity of the viral Tax-2 transactivator. Here, we show that this inhibitory effect takes place at the nuclear level and maps to the N-terminal 1-321 region of CIITA, where we identified a minimal domain, from positions 64-144, that is strictly required to suppress Tax-2 function. Furthermore, we show that Tax-2 specifically cooperates with cAMP response element binding protein-binding protein (CBP) and p300, but not with p300/CBP-associated factor, to enhance transcription from the viral promoter. This finding represents a unique difference with respect to Tax-1, which uses all three coactivators to transactivate the human T cell leukemia virus type 1 LTR. Direct sequestering of CBP or p300 is not the primary mechanism by which CIITA causes suppression of Tax-2. Interestingly, we found that the transcription factor nuclear factor Y, which interacts with CIITA to increase transcription of MHC-II genes, exerts a negative regulatory action on the Tax-2-mediated HTLV-2 LTR transactivation. Thus, CIITA may inhibit Tax-2 function, at least in part, through nuclear factor Y. These findings demonstrate the dual defensive role of CIITA against pathogens: it increases the antigen-presenting function for viral determinants and suppresses HTLV-2 replication in infected cells.
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Affiliation(s)
- Giovanna Tosi
- *Department of Clinical and Biological Sciences, University of Insubria, 21100 Varese, Italy; and
| | - Elisabetta Pilotti
- Department of Clinical Medicine, Nephrology, and Health Sciences, University of Parma, 43100 Parma, Italy
| | - Lorenzo Mortara
- *Department of Clinical and Biological Sciences, University of Insubria, 21100 Varese, Italy; and
| | - Andrea De Lerma Barbaro
- *Department of Clinical and Biological Sciences, University of Insubria, 21100 Varese, Italy; and
| | - Claudio Casoli
- Department of Clinical Medicine, Nephrology, and Health Sciences, University of Parma, 43100 Parma, Italy
| | - Roberto S. Accolla
- *Department of Clinical and Biological Sciences, University of Insubria, 21100 Varese, Italy; and
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20
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Lee KW, Lee Y, Kim DS, Kwon HJ. Direct role of NF-kappaB activation in Toll-like receptor-triggered HLA-DRA expression. Eur J Immunol 2006; 36:1254-66. [PMID: 16619292 DOI: 10.1002/eji.200535577] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Microbial components, such as DNA containing immunostimulatory CpG motifs (CpG-DNA) and lipopolysaccharides (LPS), elicit the cell surface expression of MHC class II (MHC-II) through Toll-like receptor (TLR)/IL-1R. Here, we show that CpG-DNA and LPS induce expression of the HLA-DRA in the human B cell line, RPMI 8226. Ectopic expression of the dominant negative mutant of CIITA and RNA interference targeting the CIITA gene indicate that CIITA activation is not enough for the maximal MHC-II expression induced by CpG-DNA and LPS. Additionally, nuclear factor (NF)-kappaB activation is required for the CpG-DNA-activated and LPS-activated HLA-DRA expression, whereas IFN-gamma-induced MHC-II expression depends on CIITA rather than on NF-kappaB. Comprehensive mutant analyses, electrophoretic mobility shift assays and chromatin immunoprecipitation assays, reveal that the functional interaction of NF-kappaB with the promoter element is necessary for the TLR-mediated HLA-DRA induction by CpG-DNA and LPS. This novel mechanism provides the regulation of MHC-II gene expression with complexity and functional diversity.
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Affiliation(s)
- Keun-Wook Lee
- Center for Medical Science Research, College of Medicine, Hallym University, Chuncheon Gangwon-do, Korea
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21
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Ting JPY, Kastner DL, Hoffman HM. CATERPILLERs, pyrin and hereditary immunological disorders. Nat Rev Immunol 2006; 6:183-95. [PMID: 16498449 DOI: 10.1038/nri1788] [Citation(s) in RCA: 237] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The newly described CATERPILLER family (also known as NOD-LRR or NACHT-LRR) is comprised of proteins with a nucleotide-binding domain and a leucine-rich region. This family has gained rapid prominence because of its demonstrated and anticipated roles in immunity, cell death and growth, and diseases. CATERPILLER proteins are structurally similar to a subgroup of plant-disease-resistance (R) proteins and to the apoptotic protease activating factor 1 (APAF1). They provide positive and negative signals for the control of immune and inflammatory responses, and might represent intracellular sensors of pathogen products. Most importantly, they are genetically linked to several human immunological disorders.
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Affiliation(s)
- Jenny P-Y Ting
- Department of Microbiology-Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina 27599, USA.
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22
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Krawczyk M, Reith W. Regulation of MHC class II expression, a unique regulatory system identified by the study of a primary immunodeficiency disease. ACTA ACUST UNITED AC 2006; 67:183-97. [PMID: 16573555 DOI: 10.1111/j.1399-0039.2006.00557.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Major histocompatibility complex class II (MHC-II) molecules are of central importance for adaptive immunity. Defective MHC-II expression causes a severe immunodeficiency disease called bare lymphocyte syndrome (BLS). Studies of the molecular defects underlying BLS have been pivotal for characterization of the regulatory system controlling the transcription of MHC-II genes. The precisely controlled pattern of MHC-II gene expression is achieved by a very peculiar and highly specialized molecular machinery that involves the interplay between ubiquitous DNA-binding transcription factors and a highly unusual, tightly regulated, non-DNA-binding coactivator called the MHC class II transactivator (CIITA). CIITA single handedly coordinates practically all aspects of MHC-II gene regulation and has therefore been dubbed the master controller of MHC-II expression. Several of the unusual features of the MHC-II regulatory system may be a consequence of the fact that CIITA originated from an ancient family of cytoplasmic proteins involved in inflammation and innate immunity. The function of CIITA in transcriptional regulation of MHC-II genes could thus be a recent acquisition by an ancestral protein having a role in an unrelated system.
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Affiliation(s)
- M Krawczyk
- University of Geneva Medical School, CMU, Switzerland
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23
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Drozina G, Kohoutek J, Jabrane-Ferrat N, Peterlin BM. Expression of MHC II genes. Curr Top Microbiol Immunol 2005; 290:147-70. [PMID: 16480042 DOI: 10.1007/3-540-26363-2_7] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Innate and adaptive immunity are connected via antigen processing and presentation (APP), which results in the presentation of antigenic peptides to T cells in the complex with the major histocompatibility (MHC) determinants. MHC class II (MHC II) determinants present antigens to CD4+ T cells, which are the main regulators of the immune response. Their genes are transcribed from compact promoters that form first the MHC II enhanceosome, which contains DNA-bound activators and then the MHC II transcriptosome with the addition of the class II transactivator (CIITA). CIITA is the master regulator of MHC II transcription. It is expressed constitutively in dendritic cells (DC) and mature B cells and is inducible in most other cell types. Three isoforms of CIITA exist, depending on cell type and inducing signals. CIITA is regulated at the levels of transcription and post-translational modifications, which are still not very clear. Inappropriate immune responses are found in several diseases, including cancer and autoimmunity. Since CIITA regulates the expression of MHC II genes, it is involved directly in the regulation of the immune response. The knowledge of CIITA will facilitate the manipulation of the immune response and might contribute to the treatment of these diseases.
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Affiliation(s)
- G Drozina
- Department of Medicine, Rosalind Russell Medical Research Center, University of California, San Francisco 94143, USA.
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24
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Ting JPY, Davis BK. CATERPILLER: a novel gene family important in immunity, cell death, and diseases. Annu Rev Immunol 2005; 23:387-414. [PMID: 15771576 DOI: 10.1146/annurev.immunol.23.021704.115616] [Citation(s) in RCA: 259] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The newly discovered CATERPILLER (CLR) gene family encodes proteins with a variable but limited number of N-terminal domains, followed by a nucleotide-binding domain (NBD) and leucine-rich repeats (LRR). The N-terminal domain consists of transactivation, CARD, Pyrin, or BIR domains, with a minority containing undefined domains. These proteins are remarkably similar in structure to the TIR-NBD-LRR and CC-NBD-LRR disease resistance (R) proteins that mediate immune responses in plants. The NBD-LRR architecture is conserved in plants and vertebrates, but only remnants are found in worms and flies. The CLRs regulate inflammatory and apoptotic responses, and some act as sensors that detect pathogen products. Several CLR genes have been genetically linked to susceptibility to immunologic disorders. We describe prominent family members, including CIITA, CARD4/NOD1, NOD2/CARD15, CIAS1, CARD7/NALP1, and NAIP, in more detail. We also discuss implied roles of these proteins in diversifying immune detection and in providing a check-and-balance during inflammation.
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Affiliation(s)
- Jenny P-Y Ting
- Department of Microbiology and Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
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25
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Horikawa M, Kirkman NJ, Mayo KE, Mulders SM, Zhou J, Bondy CA, Hsu SYT, King GJ, Adashi EY. The Mouse Germ-Cell-Specific Leucine-Rich Repeat Protein NALP14: A Member of the NACHT Nucleoside Triphosphatase Family1. Biol Reprod 2005; 72:879-89. [PMID: 15590904 DOI: 10.1095/biolreprod.104.033753] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Microscopy of sectioned neonatal mouse ovaries established the predominance of primordial follicles in Day 3 samples and the predominance of primary follicles by Day 8. To identify genetic determinants of the primordial to primary follicle transition, the transcriptome of Day 1 or Day 3 mouse ovaries was contrasted by differential display with that of Day 8 ovaries. This manuscript examines one of the up-regulated genes, the novel Nalp14 gene, whose transcript displayed 18- and 127-fold increments from Day 1 to Days 3 and 8, respectively. First noted by in situ hybridization in oocytes encased by primary follicles, Nalp14 transcripts were continuously expressed through the preovulatory stage. The transcripts declined when meiotic maturation resumed, and they were markedly diminished by the 2-cell embryo stage. The corresponding 3281-base pair, full-length cDNA coded for a 993 residue/104.6-kDa germ cell-specific protein. A member of the multifunctional NACHT NTPase family, the NALP14 protein featured 14 iterations of the leucine-rich-repeat domain, a region implicated in protein-protein interaction. Protein BLAST analysis of the NALP14 sequence revealed 2 previously reported germ cell-specific homologs (i.e., MATER [Maternal Antigen That Embryos Require], RNH2 [RiboNuclease/Angiogenin Inhibitor 2], and NALP4c). The structural attributes, expression pattern, and cellular localization of MATER and RNH2 largely conformed to those reported for NALP14.
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Affiliation(s)
- Michiharu Horikawa
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Utah Health Sciences Center, Salt Lake City, Utah 84112, USA
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Abstract
The tumor oncoproteins HRAS, KRAS, and NRAS are the founding members of a larger family of at least 35 related human proteins. Using a somewhat broader definition of sequence similarity reveals a more extended superfamily of more than 170 RAS-related proteins. The RAS superfamily of GTP (guanosine triphosphate) hydrolysis-coupled signal transduction relay proteins can be subclassified into RAS, RHO, RAB, and ARF families, as well as the closely related Galpha family. The members of each family can, in turn, be arranged into evolutionarily conserved branches. These groupings reflect structural, biochemical, and functional conservation. Recent findings have provided insights into the signaling characteristics of representative members of most RAS superfamily branches. The analysis presented here may serve as a guide for predicting the function of numerous uncharacterized superfamily members. Also described are guanosine triphosphatases (GTPases) distinct from members of the RAS superfamily. These related proteins employ GTP binding and GTPase domains in diverse structural contexts, expanding the scope of their function in humans.
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Xu Y, Wang L, Butticè G, Sengupta PK, Smith BD. Major histocompatibility class II transactivator (CIITA) mediates repression of collagen (COL1A2) transcription by interferon gamma (IFN-gamma). J Biol Chem 2004; 279:41319-32. [PMID: 15247294 DOI: 10.1074/jbc.m404174200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Interferon gamma (IFN-gamma) plays an important role during inflammation by repressing collagen and activating major histocompatibility class II (MHC-II) expression. Activation of MHC-II by IFN-gamma requires regulatory factor for X-box 5 (RFX5) complex as well as class II transactivator (CIITA). We have shown that the RFX family binds to the COL1A2 transcription start site, and the RFX5 complex represses COL1A2 gene expression during IFN-gamma response. In this report, we demonstrate that CIITA is a key mediator of COL1A2 repression by IFN-gamma. IFN-gamma up-regulates the expression of CIITA in a time-dependent manner in lung fibroblasts and promotes CIITA protein occupancy on COL1A2 transcription start site in vivo as judged by chromatin immunoprecipitation (ChIP) assays. There are coordinate decreases in the occupancy of RNA polymerase II on the collagen transcription start site with increasing CIITA occupancy during IFN-gamma treatment. In addition, we are able to specifically knockdown the IFN-gamma-stimulated expression of CIITA utilizing short hairpin interference RNA (shRNA) against CIITA. This leads to the alleviation of COL1A2 repression and MHC-II activation by IFN-gamma. RFX5 recruits CIITA to the collagen site as evidenced by DNA affinity chromatography. The presence of RFX5 complex proteins enhances the collagen repression by CIITA reaching levels occurring during IFN-gamma treatment. Co-expression of CIITA with deletion mutations and collagen promoter constructs demonstrates that CIITA represses collagen promoter mainly through its N-terminal region including the acidic domain and the proline/serine/threonine domain. Our data suggest that CIITA is a crucial member of a repressor complex responsible for mediating COL1A2 transcription repression by IFN-gamma.
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Affiliation(s)
- Yong Xu
- Department of Biochemistry, Boston University School of Medicine and the Veterans Administration Boston Healthcare System, Boston, Massachusetts 02118, USA
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Greer SF, Harton JA, Linhoff MW, Janczak CA, Ting JPY, Cressman DE. Serine Residues 286, 288, and 293 within the CIITA: A Mechanism for Down-Regulating CIITA Activity through Phosphorylation. THE JOURNAL OF IMMUNOLOGY 2004; 173:376-83. [PMID: 15210796 DOI: 10.4049/jimmunol.173.1.376] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CIITA is the primary factor activating the expression of the class II MHC genes necessary for the exogenous pathway of Ag processing and presentation. Strict control of CIITA is necessary to regulate MHC class II gene expression and induction of an immune response. We show in this study that the nuclear localized form of CIITA is a predominantly phosphorylated form of the protein, whereas cytoplasmic CIITA is predominantly unphosphorylated. Novel phosphorylation sites were determined to be located within a region that contains serine residues 286, 288, and 293. Double mutations of these residues increased nuclear CIITA, indicating that these sites are not required for nuclear import. CIITA-bearing mutations of these serine residues significantly increased endogenous MHC class II expression, but did not significantly enhance trans-activation from a MHC class II promoter, indicating that these phosphorylation sites may be important for gene activation from intact chromatin rather than artificial plasmid-based promoters. These data suggest a model for CIITA function in which phosphorylation of these specific sites in CIITA in the nucleus serves to down-regulate CIITA activity.
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Affiliation(s)
- Susanna F Greer
- Lineberger Comprehensive Cancer Center and Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA
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Crowley T, Brunori M, Rhee K, Wang X, Wolgemuth DJ. Change in nuclear-cytoplasmic localization of a double-bromodomain protein during proliferation and differentiation of mouse spinal cord and dorsal root ganglia. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2004; 149:93-101. [PMID: 15063089 DOI: 10.1016/j.devbrainres.2003.12.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/31/2003] [Indexed: 11/19/2022]
Abstract
The human Brd2 (Bromodomain-containing 2) gene codes for a double-bromodomain protein that associates with the cell cycle-driving transcription factors E2F-1 and E2F-2. Expression of mouse Brd2 has been shown previously to be expressed in specific patterns in proliferating cells in the developing alveoli in the mammary gland. In the present study, in situ hybridization and immunohistochemical analyses were used to examine expression of Brd2 in developing neural tissues. Brd2 mRNA was detected in brain vesicles, neural tube, spinal cord and dorsal root ganglia (DRG). Immunostaining proved that the message is translated in these tissues and further revealed that Brd2 protein localizes to the nucleus in proliferating cells, but is cytoplasmic in differentiated neurons that are no longer cycling. Brd2 protein in the nuclei of the proliferating neuronal precursors is excluded from the heterochromatin. These observations are consistent with our previous finding that nuclear localization of Brd2 protein correlates with an active cell cycle in mouse mammary alveoli during the reproductive cycle, and similar results from others in cultured fibroblasts. Our findings are also consistent with the cell cycle progression/transcription coactivator function suggested by the association of Brd2 with E2F-1 and E2F-2.
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Affiliation(s)
- ThomasE Crowley
- Department of Obstetrics and Gynecology, Columbia University Medical Center, 630 W 168th St., New York, NY 10032, USA
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Quinn G, Bower R, Dos-Santos Cruz G, Giovino M, Xu Y, Patience C, Schuurman HJ. Structural and functional characteristics of a dominant-negative isoform of porcine MHC class II transactivator. EUROPEAN JOURNAL OF IMMUNOGENETICS : OFFICIAL JOURNAL OF THE BRITISH SOCIETY FOR HISTOCOMPATIBILITY AND IMMUNOGENETICS 2003; 30:259-70. [PMID: 12919287 DOI: 10.1046/j.1365-2370.2003.00397.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The MHC class II transactivator, CIITA, is critical for MHC class II gene expression in all species studied to date. We isolated an interferon (IFN)-gamma-inducible isoform of porcine CIITA (pCIITA') encoding a protein of 566 amino acids (aa) with significant homology to human CIITA (hCIITA). Analysis indicated that pCIITA' lacks the entire GTP-binding domain that is important for nuclear translocation and activation of target genes by hCIITA. In pCIITA' this region is replaced by a 14-aa motif with homology to several signalling peptide sequences. Expression of pCIITA' in porcine (ST-IOWA) and human (HeLa) cell lines resulted in suppression of IFN-gamma-stimulated MHC class II gene expression, at the protein and mRNA levels. We also identified two IFN-gamma-inducible variants of hCIITA, hCIITAlo and hCIITA' from Hela cells, both exhibiting dominant-negative suppression of MHC class II gene expression. Interestingly, hCIITA' encodes a predicted protein of 546 aa with a strikingly similar organization to pCIITA' including the 14-aa GTP-binding domain-replacement motif in which 10 out of 14 amino acids are identical to the pig sequence. Expression of hCIITA' and hCIITAlo sequences in Hela cells suppressed IFN-gamma-induced MHC class II gene expression. hCIITAlo, a predicted 303-aa protein with deleted GTP-binding and carboxy-terminal domain, displayed a more subtle suppression of IFN-gamma-induced MHC class II expression. These in vitro data indicate that there may be a role in vivo for isoforms of CIITA that can suppress full-length CIITA-mediated MHC class II gene expression. Both humans and now, potentially, pigs are candidate donors for organ and tissue allografts and xenografts, respectively. Regulation of MHC class II gene expression by manipulation of CIITA isoform expression in humans and pigs may provide a useful strategy for attenuation of T-cell-mediated cellular rejection.
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Affiliation(s)
- G Quinn
- Imutran Limited, A Novartis Pharma AG Co, Cambridge, UK.
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