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Sali TM, Pryke KM, Abraham J, Liu A, Archer I, Broeckel R, Staverosky JA, Smith JL, Al-Shammari A, Amsler L, Sheridan K, Nilsen A, Streblow DN, DeFilippis VR. Characterization of a Novel Human-Specific STING Agonist that Elicits Antiviral Activity Against Emerging Alphaviruses. PLoS Pathog 2015; 11:e1005324. [PMID: 26646986 PMCID: PMC4672893 DOI: 10.1371/journal.ppat.1005324] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 11/12/2015] [Indexed: 12/19/2022] Open
Abstract
Pharmacologic stimulation of innate immune processes represents an attractive strategy to achieve multiple therapeutic outcomes including inhibition of virus replication, boosting antitumor immunity, and enhancing vaccine immunogenicity. In light of this we sought to identify small molecules capable of activating the type I interferon (IFN) response by way of the transcription factor IFN regulatory factor 3 (IRF3). A high throughput in vitro screen yielded 4-(2-chloro-6-fluorobenzyl)-N-(furan-2-ylmethyl)-3-oxo-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-carboxamide (referred to herein as G10), which was found to trigger IRF3/IFN-associated transcription in human fibroblasts. Further examination of the cellular response to this molecule revealed expression of multiple IRF3-dependent antiviral effector genes as well as type I and III IFN subtypes. This led to the establishment of a cellular state that prevented replication of emerging Alphavirus species including Chikungunya virus, Venezuelan Equine Encephalitis virus, and Sindbis virus. To define cellular proteins essential to elicitation of the antiviral activity by the compound we employed a reverse genetics approach that utilized genome editing via CRISPR/Cas9 technology. This allowed the identification of IRF3, the IRF3-activating adaptor molecule STING, and the IFN-associated transcription factor STAT1 as required for observed gene induction and antiviral effects. Biochemical analysis indicates that G10 does not bind to STING directly, however. Thus the compound may represent the first synthetic small molecule characterized as an indirect activator of human STING-dependent phenotypes. In vivo stimulation of STING-dependent activity by an unrelated small molecule in a mouse model of Chikungunya virus infection blocked viremia demonstrating that pharmacologic activation of this signaling pathway may represent a feasible strategy for combating emerging Alphaviruses.
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Affiliation(s)
- Tina M. Sali
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Kara M. Pryke
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Jinu Abraham
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Andrew Liu
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Iris Archer
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Rebecca Broeckel
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Julia A. Staverosky
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Jessica L. Smith
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Ahmed Al-Shammari
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
- Iraqi Centre for Cancer and Medical Genetics Research, Baghdad, Iraq
| | - Lisi Amsler
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Kayla Sheridan
- Veterans Affairs Medical Center, Portland, Oregon, United States of America
| | - Aaron Nilsen
- Veterans Affairs Medical Center, Portland, Oregon, United States of America
| | - Daniel N. Streblow
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Victor R. DeFilippis
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon, United States of America
- * E-mail:
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Amsler L, Verweij M, DeFilippis VR. The tiers and dimensions of evasion of the type I interferon response by human cytomegalovirus. J Mol Biol 2013; 425:4857-71. [PMID: 24013068 DOI: 10.1016/j.jmb.2013.08.023] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 08/28/2013] [Accepted: 08/29/2013] [Indexed: 12/29/2022]
Abstract
Human cytomegalovirus (HCMV) is a member of the β-herpesvirus family that invariably occupies hosts for life despite a consistent multi-pronged antiviral immune response that targets the infection. This persistence is enabled by the large viral genome that encodes factors conferring a wide assortment of sophisticated, often redundant phenotypes that disable or otherwise manipulate impactful immune effector processes. The type I interferon system represents a first line of host defense against infecting viruses. The physiological reactions induced by secreted interferon act to effectively block replication of a broad spectrum of virus types, including HCMV. As such, the virus must exhibit counteractive mechanisms to these responses that involve their inhibition, tolerance, or re-purposing. The goal of this review is to describe the impact of the type I interferon system on HCMV replication and to showcase the number and diversity of strategies employed by the virus that allow infection of hosts in the presence of interferon-dependent activity.
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Affiliation(s)
- Lisi Amsler
- Vaccine and Gene Therapy Institute Oregon Health and Science University 505 NW 185th Ave. Beaverton, OR, USA, 97006
| | - Marieke Verweij
- Vaccine and Gene Therapy Institute Oregon Health and Science University 505 NW 185th Ave. Beaverton, OR, USA, 97006
| | - Victor R DeFilippis
- Vaccine and Gene Therapy Institute Oregon Health and Science University 505 NW 185th Ave. Beaverton, OR, USA, 97006
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Abstract
The cellular innate immune response represents the initial reaction of a host against infecting pathogens. Host cells detect incoming microbes by way of a large and expanding array of receptors that react with evolutionarily conserved molecular patterns exhibited by microbial intruders. These receptors are responsible for initiating signaling that leads to both transcriptional activation of immunologically important genes as well as protease-dependent processing of cellular proteins. The inflammasome refers to a protein complex that functions as an activation platform for the cysteine protease caspase-1, which then processes inflammatory molecules such as IL-1β and IL-18 into functional forms. Assembly of this complex is triggered following receptor-mediated detection of pathogen-associated molecules. Receptors have been identified that are essential to inflammasome activation in response to numerous molecular patterns including virus-associated molecules such as DNA. In fact, the importance of cytoplasmic DNA as an immune stimulus is exemplified by the existence of at least nine distinct cellular receptors capable of initiating innate reactivity in response to this molecule. Viruses that employ DNA as genomic material include herpesviruses, poxviruses and adenoviruses. Each has been described as capable of inducing inflammasome-mediated activity. Interestingly, however, the cellular molecules responsible for these responses appear to vary according to host species, cell type and even viral strain. Secretion of IL-1β and IL-18 are important components of antimicrobial immunity and, as a result, pathogens have evolved factors to evade or counteract this response. This includes DNA-based viruses, many of which encode multiple redundant counteractive molecules. However, it is clear that such phenotypes are only beginning to be uncovered. The purpose of this review is to describe what is known regarding the activation of inflammasome-mediated processes in response to infection with well-examined families of DNA viruses and to discuss characterized mechanisms of manipulation and neutralization of inflammasome-dependent activity. This review aims to shed light on the biologically important phenomena regarding this virus-host interaction and to highlight key areas where important information is lacking.
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Affiliation(s)
- Lisi Amsler
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, 505, NW 185th Avenue, Beaverton, OR 97006, USA
| | - Daniel Malouli
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, 505, NW 185th Avenue, Beaverton, OR 97006, USA
| | - Victor DeFilippis
- Vaccine & Gene Therapy Institute, Oregon Health & Science University, 505, NW 185th Avenue, Beaverton, OR 97006, USA
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Amsler L, Bauernfeind P, Nigg C, Maibach RC, Steffen R, Altwegg M. Prevalence of Tropheryma whipplei DNA in patients with various gastrointestinal diseases and in healthy controls. Infection 2003; 31:81-5. [PMID: 12682812 DOI: 10.1007/s15010-002-3083-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Little is known about the epidemiology of Tropheryma whipplei and its prevalence in people without clinical signs of Whipple's disease. PATIENTS AND METHODS We screened 239 patients with various gastrointestinal diseases for T. whipplei DNA and compared them with 215 healthy controls in order to check whether T. whipplei might be a risk factor for common gastrointestinal problems or diseases. We detected the 16S rDNA of T. whipplei in salivary and stool samples using a specific seminested PCR. RESULTS The prevalence of T. whipplei DNA in patients and in controls was 4.2% (95% CI 2.0-7.6% ) and 7.0% (95% CI 4.0-11.3%), respectively. None of the different gastrointestinal diseases was associated with a higher rate of PCR-positive tests, except for the group of patients with reflux syndrome. Five out of 43 patients with reflux were found to be positive, with all five being positive in the salivary sample. This is in contrast to our findings in carriers without reflux with mainly positive stool samples (p < 0.01). CONCLUSION We conclude that the asymptomatic carrier state of T. whipplei indeed exists and that it is much more frequent than the rare Whipple's disease. The higher prevalence of T. whipplei DNA in the saliva of patients with reflux syndrome suggests that the stomach might be the habitat of the organism.
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Affiliation(s)
- L Amsler
- Swiss Federal Office of Public Health, CH-3003 Bern, Switzerland
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Abstract
In a survey among febrile European tourists in Kenya, only 68% were able to carry out immunochromatographic dipstick tests for detection of Plasmodium falciparum antigen correctly, and ten of 11 with malaria failed to diagnose themselves correctly. Rapid tests for self-diagnosis by tourists cannot be recommended without appropriate training before departure.
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