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Grycová A, Vyhlídalová B, Dvořák Z. The role of aryl hydrocarbon receptor in antiviral immunity: a focus on RNA viruses. Crit Rev Microbiol 2025:1-15. [PMID: 40299755 DOI: 10.1080/1040841x.2025.2497789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2024] [Revised: 02/02/2025] [Accepted: 04/21/2025] [Indexed: 05/01/2025]
Abstract
Aryl hydrocarbon receptor (AhR) is a ligand-dependent transcriptional factor that is activated by a plethora of exogenous and endogenous compounds, including environmental pollutants, drugs, and microbial metabolites. The AhR plays an important role in modulating immunity. Current findings suggest that AhR activation serves as a mechanism for evasion of host antiviral immune response and promotes viral replication. This review will focus on AhR's role in RNA virus infection because they show high mutation rates compared with DNA viruses, and therefo pose one of the greatest threats to humans in terms of potential pandemic risk. Indeed, they include human immunodeficiency virus (HIV), influenza A virus (IAV), coronaviruses (CoVs), Zika virus, and others. Understanding the mechanisms by which AhR influences the immune response to these viruses is critical for developing effective therapeutic strategies. By focusing on the interplay between AhR signaling and RNA virus infections, this review aims to contribute to the growing body of knowledge regarding host-pathogen interactions and the implications for antiviral immunity.
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Affiliation(s)
- Aneta Grycová
- Department of Cell Biology and Genetics, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
| | - Barbora Vyhlídalová
- Department of Cell Biology and Genetics, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Olomouc, Czech Republic
| | - Zdeněk Dvořák
- Department of Cell Biology and Genetics, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
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2
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Barreira-Silva P, Lian Y, Kaufmann SHE, Moura-Alves P. The role of the AHR in host-pathogen interactions. Nat Rev Immunol 2025; 25:178-194. [PMID: 39415055 DOI: 10.1038/s41577-024-01088-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2024] [Indexed: 10/18/2024]
Abstract
Host-microorganism encounters take place in many different ways and with different types of outcomes. Three major types of microorganisms need to be distinguished: (1) pathogens that cause harm to the host and must be controlled; (2) environmental microorganisms that can be ignored but must be controlled at higher abundance; and (3) symbiotic microbiota that require support by the host. Recent evidence indicates that the aryl hydrocarbon receptor (AHR) senses and initiates signalling and gene expression in response to a plethora of microorganisms and infectious conditions. It was originally identified as a receptor that binds xenobiotics. However, it was subsequently found to have a critical role in numerous biological processes, including immunity and inflammation and was recently classified as a pattern recognition receptor. Here we review the role of the AHR in host-pathogen interactions, focusing on AHR sensing of different microbial classes, the ligands involved, responses elicited and disease outcomes. Moreover, we explore the therapeutic potential of targeting the AHR in the context of infection.
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Affiliation(s)
- Palmira Barreira-Silva
- IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Yilong Lian
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Stefan H E Kaufmann
- Max Planck Institute for Infection Biology, Berlin, Germany
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Hagler Institute for Advanced Study, Texas A&M University, College Station, TX, USA
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Pedro Moura-Alves
- IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
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3
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Hu J, Ding Y, Liu W, Liu S. When AHR signaling pathways meet viral infections. Cell Commun Signal 2023; 21:42. [PMID: 36829212 PMCID: PMC9951170 DOI: 10.1186/s12964-023-01058-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 01/27/2023] [Indexed: 02/26/2023] Open
Abstract
Aryl hydrocarbon receptor (AHR) is a ligand-dependent transcriptional factor widely expressed among immune, epithelial, endothelial and stromal cells in barrier tissues. It can be activated by small molecules provided by pollutants, microorganisms, food, and metabolism. It has been demonstrated that AHR plays an important role in modulating the response to many microbial pathogens, and the abnormal expression of AHR signaling pathways may disrupt endocrine, cause immunotoxicity, and even lead to the occurrence of cancer. Most humans are infected with at least one known human cancer virus. While the initial infection with these viruses does not cause major disease, the metabolic activity of infected cells changes, thus affecting the activation of oncogenic signaling pathways. In the past few years, lots of studies have shown that viral infections can affect disease progression by regulating the transmission of multiple signaling pathways. This review aims to discuss the potential effects of virus infections on AHR signaling pathways so that we may find a new strategy to minimize the adverse effects of the AHR pathway on diseases. Video Abstract.
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Affiliation(s)
- Jieke Hu
- Department of Blood Transfusion, The Affiliated Hospital of Qingdao University, No. 1677 Wutaishan Road, Qingdao, 266555, China.,Department of Pathogenic Biology, Qingdao University Medical College, 308 Ningxia Road, Qingdao, 266071, China
| | - Yuan Ding
- Department of Special Examination, Qingdao Women & Children Hospital, Qingdao, 266035, China
| | - Wen Liu
- Department of Pathogenic Biology, Qingdao University Medical College, 308 Ningxia Road, Qingdao, 266071, China.
| | - Shuzhen Liu
- Department of Blood Transfusion, The Affiliated Hospital of Qingdao University, No. 1677 Wutaishan Road, Qingdao, 266555, China.
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4
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Torti MF, Giovannoni F, Quintana FJ, García CC. The Aryl Hydrocarbon Receptor as a Modulator of Anti-viral Immunity. Front Immunol 2021; 12:624293. [PMID: 33746961 PMCID: PMC7973006 DOI: 10.3389/fimmu.2021.624293] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 02/03/2021] [Indexed: 12/30/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor, which interacts with a wide range of organic molecules of endogenous and exogenous origin, including environmental pollutants, tryptophan metabolites, and microbial metabolites. The activation of AHR by these agonists drives its translocation into the nucleus where it controls the expression of a large number of target genes that include the AHR repressor (AHRR), detoxifying monooxygenases (CYP1A1 and CYP1B1), and cytokines. Recent advances reveal that AHR signaling modulates aspects of the intrinsic, innate and adaptive immune response to diverse microorganisms. This review will focus on the increasing evidence supporting a role for AHR as a modulator of the host response to viral infection.
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Affiliation(s)
- Maria Florencia Torti
- Laboratory of Antiviral Strategies, Biochemistry Department, School of Sciences, University of Buenos Aires, IQUIBICEN-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Federico Giovannoni
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Francisco Javier Quintana
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Cybele Carina García
- Laboratory of Antiviral Strategies, Biochemistry Department, School of Sciences, University of Buenos Aires, IQUIBICEN-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
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5
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Hong W, Cheng W, Zheng T, Jiang N, Xu R. AHR is a tunable knob that controls HTLV-1 latency-reactivation switching. PLoS Pathog 2020; 16:e1008664. [PMID: 32678826 PMCID: PMC7367443 DOI: 10.1371/journal.ppat.1008664] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 05/28/2020] [Indexed: 12/20/2022] Open
Abstract
Establishing latent infection but retaining the capability to reactivate in certain circumstance is an ingenious tactic for retroviruses to persist in vivo while evading host immune surveillance. Many evidences indicate that Human T-cell leukemia virus type 1 (HTLV-1) is not completely silent in vivo. However, signals that trigger HTLV-1 latency-reactivation switching remain poorly understood. Here, we show that aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, plays a critical role in HTLV-1 plus-strand expression. Importantly, HTLV-1 reactivation could be tunably manipulated by modulating the level of AHR ligands. Mechanistically, activated AHR binds to HTLV-1 LTR dioxin response element (DRE) site (CACGCATAT) and drives plus-strand transcription. On the other hand, persistent activation of nuclear factor kappa B (NF-κB) pathway constitutes one key prerequisite for AHR overexpression in HTLV-1 infected T-cells, setting the stage for the advent of AHR signaling. Our findings suggest that HTLV-1 might achieve its reactivation in vivo when encountering environmental, dietary, microbial and metabolic cues that induce sufficient AHR signaling. HTLV-1 is considered largely latent in vivo because viral products were rarely detected in freshly isolated PBMCs of infected individuals. However, the existence of strong HTLV-1-specific immune response in most infected individuals suggests that the virus should not be completely silent in vivo. Since viral gene expression plays a critical role in cell transformation and de novo infection, a novel insight into where and how HTLV-1 achieves its reactivation in vivo is essential for developing new therapeutic approaches. AHR is a ligand-activated transcription factor that regulates intricate transcriptional programs in response to environmental, dietary, microbial and metabolic cues. It has been reported that AHR is constitutively overexpressed in HTLV-1-infected T-cells. Nevertheless, the functional role of AHR in HTLV-1 pathogenesis is still obscure. In this study, we show that activated AHR can directly bind to HTLV-1 LTR DRE site (CACGCATAT) and drive HTLV-1 plus-strand transcription. Importantly, HTLV-1 latency-reactivation-latency switching could be manipulated in MT-1 cells by adding and removing additional kynurenine (a well-known AHR ligand). Moreover, we explicate that the persistent NF-κB activation is critical for AHR overexpression in HTLV-1-infected T-cells. These results imply that constitutive AHR overexpression in infected T-cells endues HTLV-1 the potential to reactivate from latency when the level of AHR ligands reaches a certain threshold. Accordingly, we propose that HTLV-1 might achieve its reactivation in certain parts of the body that are prone to accumulate AHR ligands.
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Affiliation(s)
- Weihao Hong
- School of Medicine, Huaqiao University, Quanzhou, China
- Fujian Provincial Key Laboratory of Molecular Medicine & Xiamen Key Lab of Marine and Gene Drugs, Xiamen, China
| | - Wenzhao Cheng
- School of Medicine, Huaqiao University, Quanzhou, China
- Fujian Provincial Key Laboratory of Molecular Medicine & Xiamen Key Lab of Marine and Gene Drugs, Xiamen, China
- Engineering Research Center of Molecular Medicine, Ministry of Education, Xiamen, China
| | - Tingjin Zheng
- School of Medicine, Huaqiao University, Quanzhou, China
- Fujian Provincial Key Laboratory of Molecular Medicine & Xiamen Key Lab of Marine and Gene Drugs, Xiamen, China
- Engineering Research Center of Molecular Medicine, Ministry of Education, Xiamen, China
| | - Nan Jiang
- School of Medicine, Huaqiao University, Quanzhou, China
- Fujian Provincial Key Laboratory of Molecular Medicine & Xiamen Key Lab of Marine and Gene Drugs, Xiamen, China
| | - Ruian Xu
- School of Medicine, Huaqiao University, Quanzhou, China
- Fujian Provincial Key Laboratory of Molecular Medicine & Xiamen Key Lab of Marine and Gene Drugs, Xiamen, China
- Engineering Research Center of Molecular Medicine, Ministry of Education, Xiamen, China
- * E-mail:
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6
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Tryptophan Metabolism Activates Aryl Hydrocarbon Receptor-Mediated Pathway To Promote HIV-1 Infection and Reactivation. mBio 2019; 10:mBio.02591-19. [PMID: 31848275 PMCID: PMC6918076 DOI: 10.1128/mbio.02591-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Multiple cellular metabolic pathways are altered by HIV-1 infection, with an impact on immune activation, inflammation, and acquisition of non-AIDS comorbid diseases. The dysfunction of tryptophan (Trp) metabolism has been observed clinically in association with accelerated HIV-1 pathogenesis, but the underlying mechanism remains unknown. In this study, we demonstrated that the aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, is activated by Trp metabolites to promote HIV-1 infection and reactivation. AHR directly binds to the HIV-1 5' long terminal repeat (5'-LTR) at the molecular level to activate viral transcription and infection, and AHR activation by Trp metabolites increases its nuclear translocation and association with the HIV 5'-LTR; moreover, the binding of AHR with HIV-1 Tat facilitates the recruitment of positive transcription factors to viral promoters. These findings not only elucidate a previously unappreciated mechanism through which cellular Trp metabolites affect HIV pathogenesis but also suggest that a downstream target AHR may be a potential target for modulating HIV-1 infection.IMPORTANCE Cellular metabolic pathways that are altered by HIV-1 infection may accelerate disease progression. Dysfunction in tryptophan (Trp) metabolism has been observed clinically in association with accelerated HIV-1 pathogenesis, but the mechanism responsible was not known. This study demonstrates that Trp metabolites augment the activation of aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, to promote HIV-1 infection and transcription. These findings not only elucidate a previously unappreciated mechanism through which cellular Trp metabolites affect HIV pathogenesis but also suggest that a downstream target AHR may be a potential target for modulating HIV-1 infection.
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Fiorito F, Santamaria R, Irace C, De Martino L, Iovane G. 2,3,7,8-tetrachlorodibenzo-p-dioxin and the viral infection. ENVIRONMENTAL RESEARCH 2017; 153:27-34. [PMID: 27883971 DOI: 10.1016/j.envres.2016.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 10/13/2016] [Accepted: 11/09/2016] [Indexed: 06/06/2023]
Abstract
Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a widespread highly toxic environmental contaminant, suppresses immune response and leads to an increased susceptibility to infectious agents. In particular, several studies have provided evidence that TCDD decreases resistance to numerous viruses. Indeed, in vivo and in vitro investigations showed that the presence of TCDD is able to interfere with the replication of both human and animal viruses, such as influenza A viruses, coxsackie virus B3, immunodeficiency virus type-1 (HIV-1), cytomegalovirus (CMV), herpes simplex II, and bovine herpesvirus 1. Moreover, TCDD could induce an exacerbation of latent infection produced by HIV-1, CMV or Epstein-Barr virus. In this review, we first describe the general effects of TCDD exposure on mammalian cells, then we focus on its influence on the viral infections. Overall, the available data support the concept that TCDD exposure may act as an additional risk factor in promoting of viral diseases.
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Affiliation(s)
- Filomena Fiorito
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, 80137 Naples, Italy; Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Salute 2, Portici, 80055 Naples, Italy.
| | - Rita Santamaria
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Carlo Irace
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Luisa De Martino
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, 80137 Naples, Italy.
| | - Giuseppe Iovane
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, 80137 Naples, Italy
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Yamada T, Horimoto H, Kameyama T, Hayakawa S, Yamato H, Dazai M, Takada A, Kida H, Bott D, Zhou AC, Hutin D, Watts TH, Asaka M, Matthews J, Takaoka A. Constitutive aryl hydrocarbon receptor signaling constrains type I interferon-mediated antiviral innate defense. Nat Immunol 2016; 17:687-94. [PMID: 27089381 DOI: 10.1038/ni.3422] [Citation(s) in RCA: 178] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 02/24/2016] [Indexed: 12/12/2022]
Abstract
Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that mediates the toxic activity of many environmental xenobiotics. However, its role in innate immune responses during viral infection is not fully understood. Here we demonstrate that constitutive AHR signaling negatively regulates the type I interferon (IFN-I) response during infection with various types of virus. Virus-induced IFN-β production was enhanced in AHR-deficient cells and mice and resulted in restricted viral replication. We found that AHR upregulates expression of the ADP-ribosylase TIPARP, which in turn causes downregulation of the IFN-I response. Mechanistically, TIPARP interacted with the kinase TBK1 and suppressed its activity by ADP-ribosylation. Thus, this study reveals the physiological importance of endogenous activation of AHR signaling in shaping the IFN-I-mediated innate response and, further, suggests that the AHR-TIPARP axis is a potential therapeutic target for enhancing antiviral responses.
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Affiliation(s)
- Taisho Yamada
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
| | - Hiromasa Horimoto
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.,Department of Gastroenterology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Takeshi Kameyama
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.,Molecular Medical Biochemistry Unit, Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Sumio Hayakawa
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.,Molecular Medical Biochemistry Unit, Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Hiroaki Yamato
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.,Department of Gastroenterology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Masayoshi Dazai
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.,Department of Gastroenterology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Ayato Takada
- Division of Global Epidemiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Global Station for Zoonosis Control, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan
| | - Hiroshi Kida
- Global Station for Zoonosis Control, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan.,Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Debbie Bott
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Angela C Zhou
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - David Hutin
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Tania H Watts
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | | | - Jason Matthews
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada.,Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Akinori Takaoka
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.,Molecular Medical Biochemistry Unit, Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
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Fiorito F, Cantiello A, Granato GE, Marfè G, Ciarcia R, Florio S, Pagnini U, De Martino L, Iovane G. Modulation of telomerase activity, bTERT and c-Myc induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin during Bovine Herpesvirus 1 infection in MDBK cells. Toxicol In Vitro 2014; 28:24-30. [DOI: 10.1016/j.tiv.2013.06.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 05/18/2013] [Accepted: 06/26/2013] [Indexed: 12/18/2022]
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10
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New insights into the aryl hydrocarbon receptor as a modulator of host responses to infection. Semin Immunopathol 2013; 35:615-26. [PMID: 23963494 DOI: 10.1007/s00281-013-0395-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Accepted: 07/16/2013] [Indexed: 12/23/2022]
Abstract
The host response to infection is known to be influenced by many factors, including genetics, nutritional status, age, as well as drug and chemical exposures. Recent advances reveal that the aryl hydrocarbon receptor (AhR) modulates aspects of the innate and adaptive immune response to viral, bacterial, and parasitic organisms. Although many of these observations were made using the high affinity but poorly metabolized AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), not all of the effects are detrimental to the host. Sometimes AhR activation, even with TCDD, was beneficial and improved host resistance and survival. A similar dichotomy is observed in infected AhR-deficient mice, wherein absence of functional AhR sometimes, but not always, alters host resistance. When examined in their totality, current data indicate that AhR controls multiple regulatory pathways that converge with infection-associated signals and depending on the context (e.g., type of pathogen, site of infection), lead to distinct outcomes. This creates numerous exciting opportunities to harness the immunomodulatory action of AhR to transform host responses to infection. Moreover, since many of the mechanisms cued in response to infectious agents are pivotal in the context of other diseases, there is much to be learned about AhR's cellular targets and molecular mechanisms of action.
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Fiorito F, Irace C, Di Pascale A, Colonna A, Iovane G, Pagnini U, Santamaria R, De Martino L. 2,3,7,8-Tetrachlorodibenzo-p-dioxin promotes BHV-1 infection in mammalian cells by interfering with iron homeostasis regulation. PLoS One 2013; 8:e58845. [PMID: 23520538 PMCID: PMC3592816 DOI: 10.1371/journal.pone.0058845] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 02/07/2013] [Indexed: 12/12/2022] Open
Abstract
Mammalian cells require iron to satisfy metabolic needs or to accomplish specialized functions, and DNA viruses, like bovine herpesvirus 1 (BHV-1), require an iron-replete host to efficiently replicate, so that iron bioavailability is an important component of viral virulence. Cellular iron metabolism is coordinately controlled by the Iron Regulatory Proteins (IRP1 and IRP2), whose activity is affected by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a current and persistent environmental contaminant. Considering that TCDD enhances BHV-1 replication, herein we analyzed the effects of TCDD on iron metabolism during BHV-1 infection in MDBK cells, and presented evidences of a divergent modulation of IRP1 and IRP2 RNA-binding capacity. Moreover, an up-regulation of transferrin receptor 1 (TfR1) and a concomitant down-regulation of ferritin were observed. This scenario led to an expansion of the labile iron pool (LIP) and induces a significant enhance of viral titer, as confirmed by increased levels of BHV-1 infected cell protein 0 (bICP0), the major transcriptional regulatory protein of BHV-1. Taken together, our data suggest that TCDD increases the free intracellular iron availability thereby promoting the onset of BHV-1 infection and rendering bovine cells more vulnerable to the virus.
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Affiliation(s)
- Filomena Fiorito
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Carlo Irace
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Antonio Di Pascale
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Alfredo Colonna
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Giuseppe Iovane
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Ugo Pagnini
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli “Federico II”, Naples, Italy
- * E-mail: (UP); (RS)
| | - Rita Santamaria
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Naples, Italy
- * E-mail: (UP); (RS)
| | - Luisa De Martino
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli “Federico II”, Naples, Italy
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12
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Inoue H, Mishima K, Yamamoto-Yoshida S, Ushikoshi-Nakayama R, Nakagawa Y, Yamamoto K, Ryo K, Ide F, Saito I. Aryl hydrocarbon receptor-mediated induction of EBV reactivation as a risk factor for Sjögren's syndrome. THE JOURNAL OF IMMUNOLOGY 2012; 188:4654-62. [PMID: 22467650 DOI: 10.4049/jimmunol.1101575] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates a variety of biological effects by binding to environmental pollutants, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or dioxin). Although numerous animal studies have demonstrated the harmful effects of dioxins, it remains controversial whether dioxins pose a risk to human health. Enhanced lytic replication of EBV is a risk factor for the development of autoimmune diseases and cancers. This study evaluated the possibility that ligand-activated AhR reactivates EBV. EBV reactivation and AhR transactivation were evaluated with luciferase assays. Saliva samples were collected from 19 patients with primary Sjögren's syndrome (SS). Control saliva samples were obtained from 10 healthy individuals and nine patients with severe dry mouth. TCDD enhanced BZLF1 transcription, which mediates the switch from the latent to the lytic form of EBV infection in EBV-positive B cell lines and in a salivary gland epithelial cell line. Moreover, TCDD-induced increases in BZLF1 mRNA and EBV genomic DNA levels were confirmed in the B cell lines. Saliva from SS patients activated the transcription of both CYP1A1 and BZLF1. Additionally, there was a positive correlation between CYP1A1 and BZLF1 promoter activities. AhR ligands elicited the reactivation of EBV in activated B cells and salivary epithelial cells, and these ligands are involved in SS. Our findings reveal novel aspects of the biological effects of dioxin and the AhR-dependent pathogenesis of autoimmune diseases.
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Affiliation(s)
- Hiroko Inoue
- Department of Pathology, Tsurumi University School of Dental Medicine, Kanagawa 230-8501, Japan
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13
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Fiorito F, Marfè G, Granato GE, Ciarcia R, De Blasio E, Tafani M, Florio S, De Martino L, Muzi G, Pagnini U, Giordano A. 2,3,7,8-Tetrachlorodibenzo-p-dioxin modifies expression and nuclear/cytosolic localization of bovine herpesvirus 1 immediate-early protein (bICP0) during infection. J Cell Biochem 2010; 111:333-42. [DOI: 10.1002/jcb.22700] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Feldman DN, Feldman JG, Greenblatt R, Anastos K, Pearce L, Cohen M, Gange S, Leanza S, Burk R. CYP1A1 genotype modifies the impact of smoking on effectiveness of HAART among women. AIDS EDUCATION AND PREVENTION : OFFICIAL PUBLICATION OF THE INTERNATIONAL SOCIETY FOR AIDS EDUCATION 2009; 21:81-93. [PMID: 19537956 PMCID: PMC2754267 DOI: 10.1521/aeap.2009.21.3_supp.81] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We have recently shown that cigarette smoking is associated with lesser responses to potent antiretroviral therapies. Certain Cytochrome P-450 enzymes activate compounds derived from tobacco smoke into toxic forms that may promote HIV-1 gene expression through promotion of DNA-adduct formation by the oxidation of chemical constituents of cigarette smoke, such as polyaromatic hydrocarbons and dioxins. To explore the association between environmental and genetic factors to viral replication in women who smoke and receive highly active anti-retroviral therapy (HAART), we assessed the impact of polymorphisms in a panel of four Cytochrome P-450 genes (CYP1A1, CYP2A6, CYP2D6, and CYP2E1) and two Glutathione S-transferase genes (GSTM1 and GSST1) in 924 participants of the Women's Interagency HIV Study (WIHS). Our findings showed that GSTM1 and GSST1 deletions were not associated with HAART effectiveness. By contrast, homozygosity for the CYP1A1-m1 polymorphism, was associated with impaired viral response to treatment among smokers (relative hazard (RH) = 0.54; 95% confidence interval = 0.31-0.94) after adjustment for pretreament viral load, CD4 count, age, hepatitis C infection, prior HAART therapy and race, although it had no effect among nonsmokers. We conclude that the association of the CPY1A1-m1 variant with a reduced response to HAART therapy in HIV infected smokers is consistent with this enzyme's role in the metabolic conversion of environmental toxins to DNA adducts, which may directly promote HIV-1 gene expression.
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Affiliation(s)
- David N Feldman
- Department of Pathology, University of Arizona College of Medicine, Tucson, AZ 85724, USA.
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15
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2,3,7,8-tetrachlorodibenzo-p-dioxin regulates bovine herpesvirus type 1 induced apoptosis by modulating Bcl-2 family members. Apoptosis 2008; 13:1243-52. [PMID: 18696228 DOI: 10.1007/s10495-008-0249-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Exposure to environmental contaminants, like 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), leads to an increased susceptibility to infectious agents. Infection of bovine cells (MDBK) with Bovine Herpesvirus 1 (BHV-1) anticipates virus-induced apoptosis, suggesting an involvement of TCDD in virus infection. Herein we analyzed the effects of TCDD on apoptotic pathway in MDBK cells infected with BHV-1. After 12 h of infection, TCDD induced a significant increase in apoptotic cells. TCDD caused a dose-dependent up-regulation and anticipated activation of caspases 3, 8 and 9, with respect to unexposed groups. TCDD anticipated cleavage of PARP, compared to controls. Furthermore TCDD increased Bax and Bid levels, and decreased Bcl-2 and Bcl-XL levels. Such events took place earlier in exposed than unexposed cells. These results showed that TCDD influences BHV-1 induced apoptosis through members of Bcl-2 family and up-regulating activation of caspases.
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16
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Head JL, Lawrence BP. The aryl hydrocarbon receptor is a modulator of anti-viral immunity. Biochem Pharmacol 2008; 77:642-53. [PMID: 19027719 DOI: 10.1016/j.bcp.2008.10.031] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 10/13/2008] [Accepted: 10/13/2008] [Indexed: 10/21/2022]
Abstract
Although immune modulation by AhR ligands has been studied for many years, the impact of AhR activation on host defenses against viral infection has not, until recently, garnered much attention. The development of novel reagents and model systems, new information regarding anti-viral immunity, and a growing appreciation for the global health threat posed by viruses have invigorated interest in understanding how environmental signals affect susceptibility to and pathological consequences of viral infection. Using influenza A virus as a model of respiratory viral infection, recent studies show that AhR activation cues signaling events in both leukocytes and non-immune cells. Functional alterations include suppressed lymphocyte responses and increased inflammation in the infected lung. AhR-mediated events within and extrinsic to hematopoietic cells has been investigated using bone marrow chimeras, which show that AhR alters different elements of the immune response by affecting different tissue targets. In particular, suppressed CD8(+) T cell responses are due to deregulated events within leukocytes themselves, whereas increased neutrophil recruitment to and IFN-gamma levels in the lung result from AhR-regulated events extrinsic to bone marrow-derived cells. This latter discovery suggests that epithelial and endothelial cells are overlooked targets of AhR-mediated changes in immune function. Further support that AhR influences host cell responses to viral infection are provided by several studies demonstrating that AhR interacts directly with viral proteins and affects viral latency. While AhR clearly modulates host responses to viral infection, we still have much to understand about the complex interactions between immune cells, viruses, and the host environment.
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Affiliation(s)
- Jennifer L Head
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14620, USA
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17
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Fiorito F, Pagnini U, De Martino L, Montagnaro S, Ciarcia R, Florio S, Pacilio M, Fucito A, Rossi A, Iovane G, Giordano A. 2,3,7,8-Tetrachlorodibenzo-p-dioxin increases Bovine Herpesvirus type-1 (BHV-1) replication in Madin-Darby Bovine Kidney (MDBK) cells in vitro. J Cell Biochem 2008; 103:221-33. [PMID: 17516555 DOI: 10.1002/jcb.21398] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Dioxin-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a common environmental toxin of current interest. In the last years, higher levels of TCDD than those permitted in UE [European Commission. 2002. European Commission Recommendation 2002/201/CE. Official Gazette, L 67/69] were detected in milk samples from cow, water buffalo, goat, and sheep raised on some areas of Campania Region (South Italy). Dioxin often causes immunosuppression and might render the animal liable to viral infections. In addition, viral infections are able to alter the pattern of dioxin distribution in different organs of the exposed animals. Bovine Herpesvirus type-1 (BHV-1) is a widespread pathogen, which causes infectious rhinotracheitis and infectious pustular vulvovaginitis in cattle. Herein, we have studied the effects of TCDD and BHV-1 infection, in Madin-Darby Bovine Kidney (MDBK) cells, alone as well as in association, so as cellular proliferation, apoptosis, and virus replication. We have observed an increase in cell viability of confluent monolayers at low TCDD concentrations. TCDD treated cells demonstrated increased viability compared to controls as evaluated by MTT test. TCDD exposure increased cell proliferation but induced no changes on apoptosis. Cells exposed to TCDD along with BHV-1 showed a dose-dependent increase in cytopathy, represented by ample syncytia formation with the elimination of the cellular sheets and increased viral titer. These results suggest that TCDD increases viral replication in MDBK cells while BHV-1 further decreases viability of TCDD exposed cells. Since very low concentrations (0.01 pg/ml) are sufficient to augment BHV-1 titer, TCDD may contribute to reactivate BHV-1 from latency, leading to recurrent disease and increase virus transmission.
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Affiliation(s)
- F Fiorito
- Department of Pathology and Animal Health, Naples, Italy
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18
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Enya K, Hayashi H, Takii T, Ohoka N, Kanata S, Okamoto T, Onozaki K. The interaction with Sp1 and reduction in the activity of histone deacetylase 1 are critical for the constitutive gene expression of IL-1 alpha in human melanoma cells. J Leukoc Biol 2007; 83:190-9. [PMID: 17906119 DOI: 10.1189/jlb.0106008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
A375-6 human melanoma cells are sensitive to the antiproliferative effect of IL-1. After a long period of culturing, we have obtained cells resistant to IL-1. The resistant clone A375-R8 constitutively produced IL-1 alpha. In this study, we identified a sequence, CGCC, located at -48 to -45 upstream of the transcription start site, to be essential for the constitutive IL-1 alpha gene activation. Specificity protein 1 (Sp1) and Sp3 bound to the nucleotide containing the sequence. Although the binding level to the nucleotide and expression level of Sp1 and Sp3 are comparable in A375-R8 and A375-6 cells, transactivation activity of Sp1 is higher in A375-R8 cells as compared with A375-6 cells. Sp3 could not transactivate the IL-1 alpha promoter. These results suggest that Sp1 but not Sp3 is important for IL-1 alpha gene activation. Trichostatin A (TSA), an inhibitor of histone deacetylase (HDAC), greatly augmented the IL-1 alpha promoter activity in A375-6 cells to the level comparable with that in A375-R8 cells. TSA also induced IL-1 alpha mRNA expression in A375-6 cells. Sp1 and Sp3 bound to HDAC1 in A375-R8 and A375-6 cells. The chromatin immunoprecipitation assay revealed the binding of Sp1 and HDAC1 to the promoter region of the IL-1 alpha gene. The activities of HDAC bound to Sp1 and Sp3, and that of HDAC1 was lower in A375-R8 cells as compared with A375-6 cells. These results indicate that the reduction in the activity and interaction of HDAC1 with Sp1 are critical for the constitutive IL-1 alpha gene expression.
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Affiliation(s)
- Kazuaki Enya
- Department of Molecular Health Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan
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19
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Abstract
Exposure to environmental contaminants has a profound effect on immune function, yet mechanistic understanding of how pollutants deregulate immune responses has, for many chemicals, remained elusive. Available data suggest that certain pollutants alter host immune responses and increase susceptibility to viral infection. In particular, data from a combination of epidemiological and animal studies show that exposure to dioxins, cigarette smoke, diesel exhaust and other air pollutants increase pathology associated with infection. Mechanistically, some of these chemicals disrupt the kinetics and efficacy of innate and adaptive responses to infection, whereas others influence viral latency. While there remain considerable gaps in our knowledge of the complex interactions between viruses, immune cells, and the host environment, these observations indicate that pollutants are important but overlooked contributors to susceptibility and pathogenesis of viral infections.
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Affiliation(s)
- B Paige Lawrence
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA.
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Itoh Y, Hayashi H, Miyazawa K, Kojima S, Akahoshi T, Onozaki K. 17beta-estradiol induces IL-1alpha gene expression in rheumatoid fibroblast-like synovial cells through estrogen receptor alpha (ERalpha) and augmentation of transcriptional activity of Sp1 by dissociating histone deacetylase 2 from ERalpha. THE JOURNAL OF IMMUNOLOGY 2007; 178:3059-66. [PMID: 17312152 DOI: 10.4049/jimmunol.178.5.3059] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Rheumatoid arthritis (RA) occurs four times more frequently in women than in men, although the mechanistic basis of the gender difference is unknown. RA is characterized by the overproliferation of synoviocytes producing proinflammatory cytokines such as IL-1, implicated in the pathogenesis of the disease. In this study we examined whether 17beta-estradiol (E2) induced IL-1alpha mRNA expression in the rheumatoid fibroblast-like cell line MH7A, as well as in primary synovial cells from RA patients, and investigated the underlying molecular mechanisms. E2 induced IL-1alpha mRNA expression in both cell types in an estrogen receptor-dependent manner. In MH7A cells ERalpha but not ERbeta mediated the effects of E2. Deletion and mutation analysis revealed that a GC-rich region within the IL-1alpha gene promoter was responsible for the response to E2. EMSAs showed that Sp1 and Sp3 bound to the GC-rich region and that the transcriptional activity of Sp1 was up-regulated by the treatment with E2. Sp1 and ERalpha interacted physically regardless of the presence of E2. Physical interaction was also observed between ERalpha and histone deacetylase 2 (HDAC2), and E2 induced the dissociation of HDAC2 from ERalpha. These results suggest that E2 induces the dissociation of corepressor HDAC2 from ERalpha, which leads to the augmentation of Sp1 transcriptional activity through the GC-rich region within the IL-1alpha gene promoter.
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Affiliation(s)
- Yuka Itoh
- Department of Molecular Health Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Japan
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21
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Anderson GR, Hasan A, Yin H, Qadri I, Quattrochi LC. Regulation of the CYP1A1 gene by 2,3,7,8-tetrachlorodibenzo-p-dioxin but not by beta-naphthoflavone or 3-methylcholanthrene is altered in hepatitis C virus replicon-expressing cells. Mol Pharmacol 2006; 70:1062-1070. [PMID: 16788090 DOI: 10.1124/mol.106.024125] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Exposure to hepatitis C virus (HCV) can lead to the development of cirrhosis and hepatocellular carcinoma. To examine the effects of long-term HCV infection on hepatic cytochrome P450 1A1 (CYP1A1) expression and function, we used a human hepatoma cell line expressing the HCV subgenomic replicon (Huh.8) to evaluate CYP1A1 induction by the aryl hydrocarbon receptor (AhR) ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In this study, we demonstrate that the induction of CYP1A1 expression in Huh.8 cells by TCDD but not by beta-naphthoflavone or 3-methylcholanthrene was significantly diminished. TCDD exposure of Huh.8 cells resulted in greater than 55% suppression of CYP1A1 transcription compared with the parent cell line Huh7, whereas protein levels and enzyme activities were further diminished. Suppression of CYP1A1 mRNA expression in TCDD-treated Huh.8 cells was partially reversed after pretreatment with the antioxidants N-acetylcysteine and nordihydroguaiaretic acid, suggesting a role for oxidative stress. Induced CYP1A1 message, protein, and enzyme activity were partially restored in an Huh7 cell line expressing the HCV replicon containing a deletion in the nonstructural protein NS5A. Furthermore, adenoviral expression of NS5A in Huh7 partially suppressed TCDD-induced CYP1A1 protein and enzyme activity, implicating this protein in the mechanism of suppression. These findings demonstrate that TCDD-mediated AhR signaling is impaired in hepatocytes in which HCV is present and that NS5A alone or in the presence of other nonstructural proteins of the subgenomic replicon is in part responsible.
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Affiliation(s)
- Garret R Anderson
- Department of Medicine, School of Medicine, University of Colorado at Denver and Health Sciences Center, 4200 E. 9th Avenue, Denver, CO 80262, USA
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Katagiri D, Hayashi H, Victoriano AFB, Okamoto T, Onozaki K. Estrogen stimulates transcription of human immunodeficiency virus type 1 (HIV-1). Int Immunopharmacol 2006; 6:170-81. [PMID: 16399621 DOI: 10.1016/j.intimp.2005.07.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Revised: 07/14/2005] [Accepted: 07/27/2005] [Indexed: 11/20/2022]
Abstract
Gene expression from human immunodeficiency virus (HIV) provirus is a crucial step for the viral replication. Here we examined a potential role of 17beta-estradiol (E2) in HIV-1 transcription. Transient luciferase expression studies revealed that E2 activated HIV-LTR reporter gene in HEK293 cells when the cells were co-transfected with estrogen receptor alpha (ERalpha) but not ERbeta expression plasmid. This E2 effect was abrogated by a specific antagonist to ER, ICI 182,780, indicating that it was mediated by ERalpha. Mutation analysis revealed that Sp1 binding site but not nuclear factor-kappa B (NF-kappaB) binding site of HIV-1 LTR is critical to the E2 effect. In addition, whereas E2 could not induce DNA-binding activity of NF-kappaB, E2 could augment both Sp1 DNA-binding and transcriptional activity. These findings suggest a contribution of estrogen for HIV-1 replication through ERalpha by augmenting Sp1 DNA-binding and transcriptional activity.
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Affiliation(s)
- Daichi Katagiri
- Department of Molecular Health Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan
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