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Cain MD, Klein NR, Jiang X, Salimi H, Wu Q, Miller MJ, Klimstra WB, Klein RS. Post-exposure intranasal IFNα suppresses replication and neuroinvasion of Venezuelan Equine Encephalitis virus within olfactory sensory neurons. J Neuroinflammation 2024; 21:24. [PMID: 38233868 PMCID: PMC10792865 DOI: 10.1186/s12974-023-02960-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 11/14/2023] [Indexed: 01/19/2024] Open
Abstract
BACKGROUND Venezuelan Equine Encephalitis virus (VEEV) may enter the central nervous system (CNS) within olfactory sensory neurons (OSN) that originate in the nasal cavity after intranasal exposure. While it is known that VEEV has evolved several mechanisms to inhibit type I interferon (IFN) signaling within infected cells, whether this inhibits virologic control during neuroinvasion along OSN has not been studied. METHODS We utilized an established murine model of intranasal infection with VEEV and a repository of scRNAseq data from IFN-treated OSN to assess the cellular targets and IFN signaling responses after VEEV exposure. RESULTS We found that immature OSN, which express higher levels of the VEEV receptor LDLRAD3 than mature OSN, are the first cells infected by VEEV. Despite rapid VEEV neuroinvasion after intranasal exposure, olfactory neuroepithelium (ONE) and olfactory bulb (OB) IFN responses, as assessed by evaluation of expression of interferon signaling genes (ISG), are delayed for up to 48 h during VEEV neuroinvasion, representing a potential therapeutic window. Indeed, a single intranasal dose of recombinant IFNα triggers early ISG expression in both the nasal cavity and OB. When administered at the time of or early after infection, IFNα treatment delayed onset of sequelae associated with encephalitis and extended survival by several days. VEEV replication after IFN treatment was also transiently suppressed in the ONE, which inhibited subsequent invasion into the CNS. CONCLUSIONS Our results demonstrate a critical and promising first evaluation of intranasal IFNα for the treatment of human encephalitic alphavirus exposures.
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Affiliation(s)
- Matthew D Cain
- Center for Neuroimmunology & Neuroinfectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
- Departments of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - N Rubin Klein
- Departments of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Xiaoping Jiang
- Center for Neuroimmunology & Neuroinfectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
- Departments of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Hamid Salimi
- Center for Neuroimmunology & Neuroinfectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
- Departments of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Qingping Wu
- Center for Neuroimmunology & Neuroinfectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
- Departments of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Mark J Miller
- Departments of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - William B Klimstra
- Department of Immunology and Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robyn S Klein
- Center for Neuroimmunology & Neuroinfectious Diseases, Washington University School of Medicine, St. Louis, MO, USA.
- Departments of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
- Departments of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.
- Departments of Neurosciences, Washington University School of Medicine, St. Louis, MO, USA.
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Mou C, Meng H, Shi K, Huang Y, Liu M, Chen Z. GETV nsP2 plays a critical role in the interferon antagonism and viral pathogenesis. Cell Commun Signal 2023; 21:361. [PMID: 38110975 PMCID: PMC10729338 DOI: 10.1186/s12964-023-01392-x] [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: 09/13/2023] [Accepted: 11/10/2023] [Indexed: 12/20/2023] Open
Abstract
Getah virus (GETV) was becoming more serious and posing a potential threat to animal safety and public health. Currently, there is limited comprehension regarding the pathogenesis and immune evasion mechanisms employed by GETV. Our study reveals that GETV infection exhibits the capacity for interferon antagonism. Specifically, the nonstructural protein nsP2 of GETV plays a crucial role in evading the host immune response. GETV nsP2 effectively inhibits the induction of IFN-β by blocking the phosphorylation and nuclear translocation of IRF3. Additionally, GETV nsP2 hinders the phosphorylation of STAT1 and its nuclear accumulation, leading to significantly impaired JAK-STAT signaling. Furthermore, the amino acids K648 and R649, situated in the C-terminal region of GETV nsP2, play a crucial role in facilitating nuclear localization. Not only do they affect the interference of nsP2 with the innate immune response, but they also exert an influence on the pathogenicity of GETV in mice. In summary, our study reveals novel mechanisms by which GETV evades the immune system, thereby offering a foundation for comprehending the pathogenic nature of GETV. Video Abstract.
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Affiliation(s)
- Chunxiao Mou
- College of Veterinary Medicine, Yangzhou University, No.12 Wen-hui East Road, Yangzhou, JS225009, Jiangsu Province, People's Republic of China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu Province, People's Republic of China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, Jiangsu Province, People's Republic of China
| | - Hui Meng
- College of Veterinary Medicine, Yangzhou University, No.12 Wen-hui East Road, Yangzhou, JS225009, Jiangsu Province, People's Republic of China
| | - Kaichuang Shi
- Guangxi Center for Animal Disease Control and Prevention, Nanning, GX, China
| | - Yanmei Huang
- College of Veterinary Medicine, Yangzhou University, No.12 Wen-hui East Road, Yangzhou, JS225009, Jiangsu Province, People's Republic of China
| | - Meiqi Liu
- College of Veterinary Medicine, Yangzhou University, No.12 Wen-hui East Road, Yangzhou, JS225009, Jiangsu Province, People's Republic of China
| | - Zhenhai Chen
- College of Veterinary Medicine, Yangzhou University, No.12 Wen-hui East Road, Yangzhou, JS225009, Jiangsu Province, People's Republic of China.
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu Province, People's Republic of China.
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, Jiangsu Province, People's Republic of China.
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3
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Cain MD, Klein NR, Jiang X, Klein RS. Post-exposure intranasal IFNα suppresses replication and neuroinvasion of Venezuelan Equine Encephalitis virus within olfactory sensory neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.30.547169. [PMID: 37425867 PMCID: PMC10327097 DOI: 10.1101/2023.06.30.547169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Venezuelan Equine Encephalitis virus (VEEV) may enter the central nervous system (CNS) within olfactory sensory neurons (OSN) that originate in the nasal cavity after intranasal exposure. While it is known that VEEV has evolved several mechanisms to inhibit type I interferon (IFN) signaling within infected cells, whether this inhibits virologic control during neuroinvasion along OSN has not been studied. Here, we utilized an established murine model of intranasal infection with VEEV to assess the cellular targets and IFN signaling responses after VEEV exposure. We found that immature OSN, which express higher levels of the VEEV receptor LDLRAD3 than mature OSN, are the first cells infected by VEEV. Despite rapid VEEV neuroinvasion after intranasal exposure, olfactory neuroepithelium (ONE) and olfactory bulb (OB) IFN responses, as assessed by evaluation of expression of interferon signaling genes (ISG), are delayed for up to 48 hours during VEEV neuroinvasion, representing a potential therapeutic window. Indeed, a single intranasal dose of recombinant IFNα triggers early ISG expression in both the nasal cavity and OB. When administered at the time of or early after infection, IFNα treatment delayed onset of sequelae associated with encephalitis and extended survival by several days. VEEV replication after IFN treatment was also transiently suppressed in the ONE, which inhibited subsequent invasion into the CNS. Our results demonstrate a critical and promising first evaluation of intranasal IFNα for the treatment of human encephalitic alphavirus exposures.
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Affiliation(s)
- Matthew D. Cain
- Center for Neuroimmunology & Neuroinfectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - N. Rubin Klein
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Xiaoping Jiang
- Center for Neuroimmunology & Neuroinfectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Robyn S. Klein
- Center for Neuroimmunology & Neuroinfectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
- Department of Neurosciences, Washington University School of Medicine, St. Louis, MO, USA
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Han L, Song S, Feng H, Ma J, Wei W, Si F. A roadmap for developing Venezuelan equine encephalitis virus (VEEV) vaccines: Lessons from the past, strategies for the future. Int J Biol Macromol 2023:125514. [PMID: 37353130 DOI: 10.1016/j.ijbiomac.2023.125514] [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: 04/11/2023] [Revised: 06/16/2023] [Accepted: 06/20/2023] [Indexed: 06/25/2023]
Abstract
Venezuelan equine encephalitis (VEE) is a zoonotic infectious disease caused by the Venezuelan equine encephalitis virus (VEEV), which can lead to severe central nervous system infections in both humans and animals. At present, the medical community does not possess a viable means of addressing VEE, rendering the prevention of the virus a matter of paramount importance. Regarding the prevention and control of VEEV, the implementation of a vaccination program has been recognized as the most efficient strategy. Nevertheless, there are currently no licensed vaccines or drugs available for human use against VEEV. This imperative has led to a surge of interest in vaccine research, with VEEV being a prime focus for researchers in the field. In this paper, we initially present a comprehensive overview of the current taxonomic classification of VEEV and the cellular infection mechanism of the virus. Subsequently, we provide a detailed introduction of the prominent VEEV vaccine types presently available, including inactivated vaccines, live attenuated vaccines, genetic, and virus-like particle vaccines. Moreover, we emphasize the challenges that current VEEV vaccine development faces and suggest urgent measures that must be taken to overcome these obstacles. Notably, based on our latest research, we propose the feasibility of incorporation codon usage bias strategies to create the novel VEEV vaccine. Finally, we prose several areas that future VEEV vaccine development should focus on. Our objective is to encourage collaboration between the medical and veterinary communities, expedite the translation of existing vaccines from laboratory to clinical applications, while also preparing for future outbreaks of new VEEV variants.
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Affiliation(s)
- Lulu Han
- Institute of Animal Science and Veterinary Medicine, Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, Shanghai Engineering Research Center of Breeding Pig, Shanghai 201106, China; Huaihe Hospital of Henan University, Clinical Medical College of Henan University, Kai Feng 475000, China
| | - Shuai Song
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Key Laboratory of Livestock Disease Prevention of Guangdong Province, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou 510640, PR China
| | - Huilin Feng
- Kaifeng Key Laboratory of Infection and Biological Safety, School of Basic Medical Sciences of Henan University, Kai Feng 475000, China
| | - Jing Ma
- Huaihe Hospital of Henan University, Clinical Medical College of Henan University, Kai Feng 475000, China
| | - Wenqiang Wei
- Kaifeng Key Laboratory of Infection and Biological Safety, School of Basic Medical Sciences of Henan University, Kai Feng 475000, China.
| | - Fusheng Si
- Institute of Animal Science and Veterinary Medicine, Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, Shanghai Engineering Research Center of Breeding Pig, Shanghai 201106, China.
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5
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Wu X, Chen L, Sui C, Hu Y, Jiang D, Yang F, Miller LC, Li J, Cong X, Hrabchenko N, Lee C, Du Y, Qi J. 3C pro of FMDV inhibits type II interferon-stimulated JAK-STAT signaling pathway by blocking STAT1 nuclear translocation. Virol Sin 2023; 38:387-397. [PMID: 36921803 PMCID: PMC10311264 DOI: 10.1016/j.virs.2023.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 03/08/2023] [Indexed: 03/16/2023] Open
Abstract
Foot-and-mouth disease virus (FMDV) has developed various strategies to antagonize the host innate immunity. FMDV Lpro and 3Cpro interfere with type I IFNs through different mechanisms. The structural protein VP3 of FMDV degrades Janus kinase 1 to suppress IFN-γ signaling transduction. Whether non-structural proteins of FMDV are involved in restraining type II IFN signaling pathways is unknown. In this study, it was shown that FMDV replication was resistant to IFN-γ treatment after the infection was established and FMDV inhibited type II IFN induced expression of IFN-γ-stimulated genes (ISGs). We also showed for the first time that FMDV non-structural protein 3C antagonized IFN-γ-stimulated JAK-STAT signaling pathway by blocking STAT1 nuclear translocation. 3Cpro expression significantly reduced the ISGs transcript levels and palindromic gamma-activated sequences (GAS) promoter activity, without affecting the protein level, tyrosine phosphorylation, and homodimerization of STAT1. Finally, we provided evidence that 3C protease activity played an essential role in degrading KPNA1 and thus inhibited ISGs mRNA and GAS promoter activities. Our results reveal a novel mechanism by which an FMDV non-structural protein antagonizes host type II IFN signaling.
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Affiliation(s)
- Xiangju Wu
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Lei Chen
- College of Life Science, Shandong Normal University, Jinan, 250358, China
| | - Chao Sui
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Yue Hu
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Dandan Jiang
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Fan Yang
- State Key Laboratory of Veterinary Etiological Biology/National Foot and Mouth Disease Reference Laboratory/Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730050, China
| | - Laura C Miller
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, 66506, USA
| | - Juntong Li
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Xiaoyan Cong
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Nataliia Hrabchenko
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Changhee Lee
- College of Veterinary Medicine and Virus Vaccine Research Center, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Yijun Du
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, 250100, China; College of Life Science, Shandong Normal University, Jinan, 250358, China.
| | - Jing Qi
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, 250100, China; College of Life Science, Shandong Normal University, Jinan, 250358, China.
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6
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Bhattacharjee S, Ghosh D, Saha R, Sarkar R, Kumar S, Khokhar M, Pandey RK. Mechanism of Immune Evasion in Mosquito-Borne Diseases. Pathogens 2023; 12:pathogens12050635. [PMID: 37242305 DOI: 10.3390/pathogens12050635] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
In recent decades, mosquito-borne illnesses have emerged as a major health burden in many tropical regions. These diseases, such as malaria, dengue fever, chikungunya, yellow fever, Zika virus infection, Rift Valley fever, Japanese encephalitis, and West Nile virus infection, are transmitted through the bite of infected mosquitoes. These pathogens have been shown to interfere with the host's immune system through adaptive and innate immune mechanisms, as well as the human circulatory system. Crucial immune checkpoints such as antigen presentation, T cell activation, differentiation, and proinflammatory response play a vital role in the host cell's response to pathogenic infection. Furthermore, these immune evasions have the potential to stimulate the human immune system, resulting in other associated non-communicable diseases. This review aims to advance our understanding of mosquito-borne diseases and the immune evasion mechanisms by associated pathogens. Moreover, it highlights the adverse outcomes of mosquito-borne disease.
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Affiliation(s)
| | - Debanjan Ghosh
- Department of Biotechnology, Pondicherry University, Puducherry 605014, India
| | - Rounak Saha
- Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry 605014, India
| | - Rima Sarkar
- DBT Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
| | - Saurav Kumar
- DBT Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
| | - Manoj Khokhar
- Department of Biochemistry, AIIMS, Jodhpur 342005, India
| | - Rajan Kumar Pandey
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Solna, Sweden
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7
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Ramos da Silva J, Bitencourt Rodrigues K, Formoso Pelegrin G, Silva Sales N, Muramatsu H, de Oliveira Silva M, Porchia BFMM, Moreno ACR, Aps LRMM, Venceslau-Carvalho AA, Tombácz I, Fotoran WL, Karikó K, Lin PJC, Tam YK, de Oliveira Diniz M, Pardi N, de Souza Ferreira LC. Single immunizations of self-amplifying or non-replicating mRNA-LNP vaccines control HPV-associated tumors in mice. Sci Transl Med 2023; 15:eabn3464. [PMID: 36867683 DOI: 10.1126/scitranslmed.abn3464] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
As mRNA vaccines have proved to be very successful in battling the coronavirus disease 2019 (COVID-19) pandemic, this new modality has attracted widespread interest for the development of potent vaccines against other infectious diseases and cancer. Cervical cancer caused by persistent human papillomavirus (HPV) infection is a major cause of cancer-related deaths in women, and the development of safe and effective therapeutic strategies is urgently needed. In the present study, we compared the performance of three different mRNA vaccine modalities to target tumors associated with HPV-16 infection in mice. We generated lipid nanoparticle (LNP)-encapsulated self-amplifying mRNA as well as unmodified and nucleoside-modified non-replicating mRNA vaccines encoding a chimeric protein derived from the fusion of the HPV-16 E7 oncoprotein and the herpes simplex virus type 1 glycoprotein D (gDE7). We demonstrated that single low-dose immunizations with any of the three gDE7 mRNA vaccines induced activation of E7-specific CD8+ T cells, generated memory T cell responses capable of preventing tumor relapses, and eradicated subcutaneous tumors at different growth stages. In addition, the gDE7 mRNA-LNP vaccines induced potent tumor protection in two different orthotopic mouse tumor models after administration of a single vaccine dose. Last, comparative studies demonstrated that all three gDE7 mRNA-LNP vaccines proved to be superior to gDE7 DNA and gDE7 recombinant protein vaccines. Collectively, we demonstrated the immunogenicity and therapeutic efficacy of three different mRNA vaccines in extensive comparative experiments. Our data support further evaluation of these mRNA vaccines in clinical trials.
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Affiliation(s)
- Jamile Ramos da Silva
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil.,Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Karine Bitencourt Rodrigues
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil
| | - Guilherme Formoso Pelegrin
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil
| | - Natiely Silva Sales
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil
| | - Hiromi Muramatsu
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mariângela de Oliveira Silva
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil
| | - Bruna F M M Porchia
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil.,Laboratory of Tumor Immunology, Department of Immunology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP 05508-000, Brazil.,ImunoTera Soluções Terapêuticas Ltda., São Paulo, SP 05508-000, Brazil
| | - Ana Carolina Ramos Moreno
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil
| | - Luana Raposo M M Aps
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil.,ImunoTera Soluções Terapêuticas Ltda., São Paulo, SP 05508-000, Brazil
| | - Aléxia Adrianne Venceslau-Carvalho
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil
| | - István Tombácz
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Wesley Luzetti Fotoran
- Department of Parasitology, Institute for Biomedical Sciences, University of São Paulo, SP 05508-000, Brazil
| | | | | | - Ying K Tam
- Acuitas Therapeutics, Vancouver, BC V6T1Z3, Canada
| | - Mariana de Oliveira Diniz
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil
| | - Norbert Pardi
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Luís Carlos de Souza Ferreira
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil.,Scientific Platform Pasteur USP, University of São Paulo, São Paulo, SP, 05508-020, Brazil
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8
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Behnia M, Bradfute SB. The Host Non-Coding RNA Response to Alphavirus Infection. Viruses 2023; 15:v15020562. [PMID: 36851776 PMCID: PMC9967650 DOI: 10.3390/v15020562] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/10/2023] [Accepted: 02/15/2023] [Indexed: 02/22/2023] Open
Abstract
Alphaviruses are important human and animal pathogens that can cause a range of debilitating symptoms and are found worldwide. These include arthralgic diseases caused by Old-World viruses and encephalitis induced by infection with New-World alphaviruses. Non-coding RNAs do not encode for proteins, but can modulate cellular response pathways in a myriad of ways. There are several classes of non-coding RNAs, some more well-studied than others. Much research has focused on the mRNA response to infection against alphaviruses, but analysis of non-coding RNA responses has been more limited until recently. This review covers what is known regarding host cell non-coding RNA responses in alphavirus infections and highlights gaps in the knowledge that future research should address.
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Abstract
Alphaviruses contain many human and animal pathogens, such as CHIKV, SINV, and VEEV. Accumulating evidence indicates that innate immunity plays an important role in response to alphaviruses infection. In parallel, alphaviruses have evolved many strategies to evade host antiviral innate immunity. In the current review, we focus on the underlying mechanisms employed by alphaviruses to evade cGAS-STING, IFN, transcriptional host shutoff, translational host shutoff, and RNAi. Dissecting the detailed antiviral immune evasion mechanisms by alphaviruses will enhance our understanding of the pathogenesis of alphaviruses and may provide more effective strategies to control alphaviruses infection.
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Affiliation(s)
- Yihan Liu
- Department of Infectious Diseases, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Yupei Yuan
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Leiliang Zhang
- Department of Infectious Diseases, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
- *Correspondence: Leiliang Zhang,
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10
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Maruggi G, Ulmer JB, Rappuoli R, Yu D. Self-amplifying mRNA-Based Vaccine Technology and Its Mode of Action. Curr Top Microbiol Immunol 2022; 440:31-70. [PMID: 33861374 DOI: 10.1007/82_2021_233] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Self-amplifying mRNAs derived from the genomes of positive-strand RNA viruses have recently come into focus as a promising technology platform for vaccine development. Non-virally delivered self-amplifying mRNA vaccines have the potential to be highly versatile, potent, streamlined, scalable, and inexpensive. By amplifying their genome and the antigen encoding mRNA in the host cell, the self-amplifying mRNA mimics a viral infection, resulting in sustained levels of the target protein combined with self-adjuvanting innate immune responses, ultimately leading to potent and long-lasting antigen-specific humoral and cellular immune responses. Moreover, in principle, any eukaryotic sequence could be encoded by self-amplifying mRNA without the need to change the manufacturing process, thereby enabling a much faster and flexible research and development timeline than the current vaccines and hence a quicker response to emerging infectious diseases. This chapter highlights the rapid progress made in using non-virally delivered self-amplifying mRNA-based vaccines against infectious diseases in animal models. We provide an overview of the unique attributes of this vaccine approach, summarize the growing body of work defining its mechanism of action, discuss the current challenges and latest advances, and highlight perspectives about the future of this promising technology.
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Affiliation(s)
| | | | | | - Dong Yu
- GSK, 14200 Shady Grove Road, Rockville, MD, 20850, USA. .,Dynavax Technologies, 2100 Powell Street Suite, Emeryville, CA, 94608, USA.
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11
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The C-Terminal Domain of Salmonid Alphavirus Nonstructural Protein 2 (nsP2) Is Essential and Sufficient To Block RIG-I Pathway Induction and Interferon-Mediated Antiviral Response. J Virol 2021; 95:e0115521. [PMID: 34523969 DOI: 10.1128/jvi.01155-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Salmonid alphavirus (SAV) is an atypical alphavirus that has a considerable impact on salmon and trout farms. Unlike other alphaviruses, such as the chikungunya virus, SAV is transmitted without an arthropod vector, and it does not cause cell shutoff during infection. The mechanisms by which SAV escapes the host immune system remain unknown. By studying the role of SAV proteins on the RIG-I signaling cascade, the first line of defense of the immune system during infection, we demonstrated that nonstructural protein 2 (nsP2) effectively blocks the induction of type I interferon (IFN). This inhibition, independent of the protease activity carried by nsP2, occurs downstream of IRF3, which is the transcription factor allowing the activation of the IFN promoter and its expression. The inhibitory effect of nsP2 on the RIG-I pathway depends on the localization of nsP2 in the host cell nucleus, which is linked to two nuclear localization sequences (NLS) located in its C-terminal part. The C-terminal domain of nsP2 by itself is sufficient and necessary to block IFN induction. Mutation of the NLS of nsP2 is deleterious to the virus. Finally, nsP2 does not interact with IRF3, indicating that its action is possible through a targeted interaction within discrete areas of chromatin, as suggested by its punctate distribution observed in the nucleus. These results therefore demonstrate a major role for nsP2 in the control by SAV of the host cell's innate immune response. IMPORTANCE The global consumption of fish continues to rise, and the future demand cannot be met by capture fisheries alone due to limited stocks of wild fish. Aquaculture is currently the world's fastest-growing food production sector, with an annual growth rate of 6 to 8%. Recurrent outbreaks of SAV result in significant economic losses with serious environmental consequences for wild stocks. While the clinical and pathological signs of SAV infection are fairly well known, the molecular mechanisms involved are poorly described. In the present study, we focus on the nonstructural protein nsP2 and characterize a specific domain containing nuclear localization sequences that are critical for the inhibition of the host innate immune response mediated by the RIG-I pathway.
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12
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Identification of Quinolinones as Antivirals against Venezuelan Equine Encephalitis Virus. Antimicrob Agents Chemother 2021; 65:e0024421. [PMID: 34152810 DOI: 10.1128/aac.00244-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Venezuelan equine encephalitis virus (VEEV) is a reemerging alphavirus that can cause encephalitis resulting in severe human morbidity and mortality. Using a high-throughput cell-based screen, we identified a quinolinone compound that protected against VEEV-induced cytopathic effects. Analysis of viral replication in cells identified several quinolinone compounds with potent inhibitory activity against vaccine and virulent strains of VEEV. These quinolinones also displayed inhibitory activity against additional alphaviruses, such as Mayaro virus and Ross River virus, although the potency was greatly reduced. Time-of-addition studies indicated that these compounds inhibit the early-to-mid stage of viral replication. Deep sequencing and reverse genetics studies identified two unique resistance mutations in the nsP2 gene (Y102S/C; stalk domain) that conferred VEEV resistance on this chemical series. Moreover, introduction of a K102Y mutation into the nsP2 gene enhanced the sensitivity of chikungunya virus (CHIKV) to this chemical series. Computational modeling of CHIKV and VEEV nsP2 identified a highly probable docking alignment for the quinolinone compounds that require a tyrosine residue at position 102 within the helicase stalk domain. These studies identified a class of compounds with antiviral activity against VEEV and other alphaviruses and provide further evidence that therapeutics targeting nsP2 may be useful against alphavirus infection.
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13
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Facile method for delivering chikungunya viral replicons into mosquitoes and mammalian cells. Sci Rep 2021; 11:12321. [PMID: 34112897 PMCID: PMC8192953 DOI: 10.1038/s41598-021-91830-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 06/01/2021] [Indexed: 11/09/2022] Open
Abstract
Reverse genetics is an important tool in the elucidation of viral replication and the development of countermeasures; however, these methods are impeded by laborious and inefficient replicon delivery methods. This paper demonstrates the use of a baculovirus to facilitate the efficient delivery of autonomous CHIKV replicons into mosquito and mammalian cells in vitro as well as adult mosquitoes in vivo. The efficacy of this approach was verified via co-localization among an eGFP reporter, nsP1, and dsRNA as well as through the inhibition of an RNA-dependent RNA polymerase (RdRp) null mutation (DDAA) in nsP4, or the treatment of a known antiviral compound (6-azauridine). We also investigated the correlation between CHIKV replicon-launched eGFP expression and the effectiveness of CHIKV replicon variants in inducing IFN-β expression in human cell lines. This delivery method based on a single vector is applicable to mosquito and mammalian cells in seeking to decipher the mechanisms underlying CHIKV replication, elucidate virus-host interactions, and develop antivirals. This study presents an effective alternative to overcome many of the technological issues related to the study and utilization of autonomous arbovirus replicons.
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14
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Bengue M, Ferraris P, Barthelemy J, Diagne CT, Hamel R, Liégeois F, Nougairède A, de Lamballerie X, Simonin Y, Pompon J, Salinas S, Missé D. Mayaro Virus Infects Human Brain Cells and Induces a Potent Antiviral Response in Human Astrocytes. Viruses 2021; 13:v13030465. [PMID: 33799906 PMCID: PMC8001792 DOI: 10.3390/v13030465] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/17/2021] [Accepted: 03/08/2021] [Indexed: 12/22/2022] Open
Abstract
Mayaro virus (MAYV) and chikungunya virus (CHIKV) are known for their arthrotropism, but accumulating evidence shows that CHIKV infections are occasionally associated with serious neurological complications. However, little is known about the capacity of MAYV to invade the central nervous system (CNS). We show that human neural progenitors (hNPCs), pericytes and astrocytes are susceptible to MAYV infection, resulting in the production of infectious viral particles. In primary astrocytes, MAYV, and to a lesser extent CHIKV, elicited a strong antiviral response, as demonstrated by an increased expression of several interferon-stimulated genes, including ISG15, MX1 and OAS2. Infection with either virus led to an enhanced expression of inflammatory chemokines, such as CCL5, CXCL10 and CXCL11, whereas MAYV induced higher levels of IL-6, IL-12 and IL-15 in these cells. Moreover, MAYV was more susceptible than CHIKV to the antiviral effects of both type I and type II interferons. Taken together, this study shows that although MAYV and CHIKV are phylogenetically related, they induce different types of antiviral responses in astrocytes. This work is the first to evaluate the potential neurotropism of MAYV and shows that brain cells and particularly astrocytes and hNPCs are permissive to MAYV, which, consequently, could lead to MAYV-induced neuropathology.
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Affiliation(s)
- Michèle Bengue
- MIVEGEC, Université de Montpellier, IRD, CNRS, 34394 Montpellier, France; (M.B.); (P.F.); (C.T.D.); (R.H.); (F.L.); (J.P.)
| | - Pauline Ferraris
- MIVEGEC, Université de Montpellier, IRD, CNRS, 34394 Montpellier, France; (M.B.); (P.F.); (C.T.D.); (R.H.); (F.L.); (J.P.)
| | - Jonathan Barthelemy
- Pathogenesis and Control of Chronic Infections, Inserm, Université de Montpellier, Etablissement Français du Sang, 34394 Montpellier, France; (J.B.); (Y.S.)
| | - Cheikh Tidiane Diagne
- MIVEGEC, Université de Montpellier, IRD, CNRS, 34394 Montpellier, France; (M.B.); (P.F.); (C.T.D.); (R.H.); (F.L.); (J.P.)
| | - Rodolphe Hamel
- MIVEGEC, Université de Montpellier, IRD, CNRS, 34394 Montpellier, France; (M.B.); (P.F.); (C.T.D.); (R.H.); (F.L.); (J.P.)
| | - Florian Liégeois
- MIVEGEC, Université de Montpellier, IRD, CNRS, 34394 Montpellier, France; (M.B.); (P.F.); (C.T.D.); (R.H.); (F.L.); (J.P.)
| | - Antoine Nougairède
- Unité Des Virus Emergents (UVE, Aix Marseille Université, IRD 190, Inserm 1207, IHU Méditerranée Infection), 13005 Marseille, France; (A.N.); (X.d.L.)
| | - Xavier de Lamballerie
- Unité Des Virus Emergents (UVE, Aix Marseille Université, IRD 190, Inserm 1207, IHU Méditerranée Infection), 13005 Marseille, France; (A.N.); (X.d.L.)
| | - Yannick Simonin
- Pathogenesis and Control of Chronic Infections, Inserm, Université de Montpellier, Etablissement Français du Sang, 34394 Montpellier, France; (J.B.); (Y.S.)
| | - Julien Pompon
- MIVEGEC, Université de Montpellier, IRD, CNRS, 34394 Montpellier, France; (M.B.); (P.F.); (C.T.D.); (R.H.); (F.L.); (J.P.)
| | - Sara Salinas
- Pathogenesis and Control of Chronic Infections, Inserm, Université de Montpellier, Etablissement Français du Sang, 34394 Montpellier, France; (J.B.); (Y.S.)
- Correspondence: (S.S.); (D.M.)
| | - Dorothée Missé
- MIVEGEC, Université de Montpellier, IRD, CNRS, 34394 Montpellier, France; (M.B.); (P.F.); (C.T.D.); (R.H.); (F.L.); (J.P.)
- Correspondence: (S.S.); (D.M.)
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15
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Abstract
Messenger RNA (mRNA) has immense potential for developing a wide range of therapies, including immunotherapy and protein replacement. As mRNA presents no risk of integration into the host genome and does not require nuclear entry for transfection, which allows protein production even in nondividing cells, mRNA-based approaches can be envisioned as safe and practical therapeutic strategies. Nevertheless, mRNA presents unfavorable characteristics, such as large size, immunogenicity, limited cellular uptake, and sensitivity to enzymatic degradation, which hinder its use as a therapeutic agent. While mRNA stability and immunogenicity have been ameliorated by direct modifications on the mRNA structure, further improvements in mRNA delivery are still needed for promoting its activity in biological settings. In this regard, nanomedicine has shown the ability for spatiotemporally controlling the function of a myriad of bioactive agents in vivo. Direct engineering of nanomedicine structures for loading, protecting, and releasing mRNA and navigating in biological environments can then be applied for promoting mRNA translation toward the development of effective treatments. Here, we review recent approaches aimed at enhancing mRNA function and its delivery through nanomedicines, with particular emphasis on their applications and eventual clinical translation.
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Affiliation(s)
- Satoshi Uchida
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.,Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14, Tonomachi, Kawasaki 210-0821, Japan
| | - Federico Perche
- Centre de Biophysique Moléculaire, UPR4301 CNRS Rue Charles Sadron Orléans, Orléans 45071 Cedex 02, France
| | - Chantal Pichon
- Centre de Biophysique Moléculaire, UPR4301 CNRS Rue Charles Sadron Orléans, Orléans 45071 Cedex 02, France.,Faculty of Sciences and Techniques, University of Orléans, Orléans 45071 Cedex 02, France
| | - Horacio Cabral
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.,Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14, Tonomachi, Kawasaki 210-0821, Japan
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16
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Identification of Natural Molecular Determinants of Ross River Virus Type I Interferon Modulation. J Virol 2020; 94:JVI.01788-19. [PMID: 31996431 DOI: 10.1128/jvi.01788-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/24/2020] [Indexed: 02/08/2023] Open
Abstract
Ross River virus (RRV) belongs to the genus Alphavirus and is prevalent in Australia. RRV infection can cause arthritic symptoms in patients and may include rash, fever, arthralgia, and myalgia. Type I interferons (IFN) are the primary antiviral cytokines and trigger activation of the host innate immune system to suppress the replication of invading viruses. Alphaviruses are able to subvert the type I IFN system, but the mechanisms used are ill defined. In this study, seven RRV field strains were analyzed for induction of and sensitivity to type I IFN. The sensitivities of these strains to human IFN-β varied significantly and were highest for the RRV 2548 strain. Compared to prototype laboratory strain RRV-T48, RRV 2548 also induced higher type I IFN levels both in vitro and in vivo and caused milder disease. To identify the determinants involved in type I IFN modulation, the region encoding the nonstructural proteins (nsPs) of RRV 2548 was sequenced, and 42 amino acid differences from RRV-T48 were identified. Using fragment swapping and site-directed mutagenesis, we discovered that substitutions E402A and R522Q in nsP1 as well as Q619R in nsP2 were responsible for increased sensitivity of RRV 2548 to type I IFN. In contrast, substitutions A31T, N219T, S580L, and Q619R in nsP2 led to induction of higher levels of type I IFN. With exception of E402A, all these variations are common for naturally occurring RRV strains. However, they are different from all known determinants of type I IFN modulation reported previously in nsPs of alphaviruses.IMPORTANCE By identifying natural Ross River virus (RRV) amino acid determinants for type I interferon (IFN) modulation, this study gives further insight into the mechanism of type I IFN modulation by alphaviruses. Here, the crucial role of type I IFN in the early stages of RRV disease pathogenesis is further demonstrated. This study also provides a comparison of the roles of different parts of the RRV nonstructural region in type I IFN modulation, highlighting the importance of nonstructural protein 1 (nsP1) and nsP2 in this process. Three substitutions in nsP1 and nsP2 were found to be independently associated with enhanced type I IFN sensitivity, and four independent substitutions in nsP2 were important in elevated type I IFN induction. Such evidence has clear implications for RRV immunobiology, persistence, and pathology. The identification of viral proteins that modulate type I IFN may also have importance for the pathogenesis of other alphaviruses.
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17
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Huysmans H, Zhong Z, De Temmerman J, Mui BL, Tam YK, Mc Cafferty S, Gitsels A, Vanrompay D, Sanders NN. Expression Kinetics and Innate Immune Response after Electroporation and LNP-Mediated Delivery of a Self-Amplifying mRNA in the Skin. MOLECULAR THERAPY. NUCLEIC ACIDS 2019; 17:867-878. [PMID: 31472371 PMCID: PMC6722285 DOI: 10.1016/j.omtn.2019.08.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/22/2019] [Accepted: 08/01/2019] [Indexed: 12/23/2022]
Abstract
In this work, we studied the expression kinetics and innate immune response of a self-amplifying mRNA (sa-RNA) after electroporation and lipid-nanoparticle (LNP)-mediated delivery in the skin of mice. Intradermal electroporation of the sa-RNA resulted in a plateau-shaped expression, with the plateau between day 3 and day 10. The overall protein expression of sa-RNA was significantly higher than that obtained after electroporation of plasmid DNA (pDNA) or non-replication mRNAs. Moreover, using IFN-β reporter mice, we elucidated that intradermal electroporation of sa-RNA induced a short-lived moderate innate immune response, which did not affect the expression of the sa-RNA. A completely different expression profile and innate immune response were observed when LNPs were used. The expression peaked 24 h after intradermal injection of sa-RNA-LNPs and subsequently showed a sharp drop. This drop might be explained by a translational blockage caused by the strong innate immune response that we observed in IFN-β reporter mice shortly (4 h) after intradermal injection of sa-RNA-LNPs. A final interesting observation was the capacity of sa-RNA-LNPs to transfect the draining lymph nodes after intradermal injection.
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Affiliation(s)
- Hanne Huysmans
- Laboratory of Gene Therapy, Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
| | - Zifu Zhong
- Laboratory of Gene Therapy, Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
| | - Joyca De Temmerman
- Laboratory of Gene Therapy, Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium; Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
| | | | - Ying K Tam
- Acuitas Therapeutics, Vancouver, BC V6T 1Z3, Canada
| | - Séan Mc Cafferty
- Laboratory of Gene Therapy, Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium; Cancer Research Institute (CRIG), Ghent University, Ghent, Belgium
| | - Arlieke Gitsels
- Laboratory of Gene Therapy, Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium; Laboratory for Immunology and Animal Biotechnology, Department of Animal Production, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Daisy Vanrompay
- Laboratory for Immunology and Animal Biotechnology, Department of Animal Production, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Niek N Sanders
- Laboratory of Gene Therapy, Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium; Cancer Research Institute (CRIG), Ghent University, Ghent, Belgium.
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18
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Sharma A, Knollmann-Ritschel B. Current Understanding of the Molecular Basis of Venezuelan Equine Encephalitis Virus Pathogenesis and Vaccine Development. Viruses 2019; 11:v11020164. [PMID: 30781656 PMCID: PMC6410161 DOI: 10.3390/v11020164] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 01/30/2019] [Accepted: 02/07/2019] [Indexed: 12/30/2022] Open
Abstract
Dedication This review is dedicated in the memory of Dr Radha K. Maheshwari, a great mentor and colleague, whose passion for research and student training has left a lasting effect on this manuscript and many other works. Abstract Venezuelan equine encephalitis virus (VEEV) is an alphavirus in the family Togaviridae. VEEV is highly infectious in aerosol form and a known bio-warfare agent that can cause severe encephalitis in humans. Periodic outbreaks of VEEV occur predominantly in Central and South America. Increased interest in VEEV has resulted in a more thorough understanding of the pathogenesis of this disease. Inflammation plays a paradoxical role of antiviral response as well as development of lethal encephalitis through an interplay between the host and viral factors that dictate virus replication. VEEV has efficient replication machinery that adapts to overcome deleterious mutations in the viral genome or improve interactions with host factors. In the last few decades there has been ongoing development of various VEEV vaccine candidates addressing the shortcomings of the current investigational new drugs or approved vaccines. We review the current understanding of the molecular basis of VEEV pathogenesis and discuss various types of vaccine candidates.
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Affiliation(s)
- Anuj Sharma
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
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19
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Morazzani EM, Compton JR, Leary DH, Berry AV, Hu X, Marugan JJ, Glass PJ, Legler PM. Proteolytic cleavage of host proteins by the Group IV viral proteases of Venezuelan equine encephalitis virus and Zika virus. Antiviral Res 2019; 164:106-122. [PMID: 30742841 DOI: 10.1016/j.antiviral.2019.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 01/13/2019] [Accepted: 02/01/2019] [Indexed: 12/12/2022]
Abstract
The alphaviral nonstructural protein 2 (nsP2) cysteine proteases (EC 3.4.22.-) are essential for the proteolytic processing of the nonstructural (ns) polyprotein and are validated drug targets. A common secondary role of these proteases is to antagonize the effects of interferon (IFN). After delineating the cleavage site motif of the Venezuelan equine encephalitis virus (VEEV) nsP2 cysteine protease, we searched the human genome to identify host protein substrates. Here we identify a new host substrate of the VEEV nsP2 protease, human TRIM14, a component of the mitochondrial antiviral-signaling protein (MAVS) signalosome. Short stretches of homologous host-pathogen protein sequences (SSHHPS) are present in the nonstructural polyprotein and TRIM14. A 25-residue cyan-yellow fluorescent protein TRIM14 substrate was cleaved in vitro by the VEEV nsP2 protease and the cleavage site was confirmed by tandem mass spectrometry. A TRIM14 cleavage product also was found in VEEV-infected cell lysates. At least ten other Group IV (+)ssRNA viral proteases have been shown to cleave host proteins involved in generating the innate immune responses against viruses, suggesting that the integration of these short host protein sequences into the viral protease cleavage sites may represent an embedded mechanism of IFN antagonism. This interference mechanism shows several parallels with those of CRISPR/Cas9 and RNAi/RISC, but with a protease recognizing a protein sequence common to both the host and pathogen. The short host sequences embedded within the viral genome appear to be analogous to the short phage sequences found in a host's CRISPR spacer sequences. To test this algorithm, we applied it to another Group IV virus, Zika virus (ZIKV), and identified cleavage sites within human SFRP1 (secreted frizzled related protein 1), a retinal Gs alpha subunit, NT5M, and Forkhead box protein G1 (FOXG1) in vitro. Proteolytic cleavage of these proteins suggests a possible link between the protease and the virus-induced phenotype of ZIKV. The algorithm may have value for selecting cell lines and animal models that recapitulate virus-induced phenotypes, predicting host-range and susceptibility, selecting oncolytic viruses, identifying biomarkers, and de-risking live virus vaccines. Inhibitors of the proteases that utilize this mechanism may both inhibit viral replication and alleviate suppression of the innate immune responses.
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Affiliation(s)
- Elaine M Morazzani
- United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
| | - Jaimee R Compton
- Center for Bio/molecular Science and Engineering, U.S. Naval Research Laboratory, Washington, DC 20375, USA
| | - Dagmar H Leary
- Center for Bio/molecular Science and Engineering, U.S. Naval Research Laboratory, Washington, DC 20375, USA
| | | | - Xin Hu
- NIH Chemical Genomics Center, National Center for Advancing Translational Sciences, Rockville, MD 20850, USA
| | - Juan J Marugan
- NIH Chemical Genomics Center, National Center for Advancing Translational Sciences, Rockville, MD 20850, USA
| | - Pamela J Glass
- United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
| | - Patricia M Legler
- Center for Bio/molecular Science and Engineering, U.S. Naval Research Laboratory, Washington, DC 20375, USA.
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20
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Decreased Virulence of Ross River Virus Harboring a Mutation in the First Cleavage Site of Nonstructural Polyprotein Is Caused by a Novel Mechanism Leading to Increased Production of Interferon-Inducing RNAs. mBio 2018; 9:mBio.00044-18. [PMID: 30131356 PMCID: PMC6106088 DOI: 10.1128/mbio.00044-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Infection with Ross River virus (RRV) causes debilitating polyarthritis and arthralgia in individuals. Alphaviruses are highly sensitive to type I interferon (IFN). Mutations at the conserved P3 position of the cleavage site between nonstructural protein 1 (nsP1) and nsP2 (1/2 site) modulate type I IFN induction for both RRV and Sindbis virus (SINV). We constructed and characterized RRV-T48A534V, a mutant harboring an A534V substitution in the P1 position of the 1/2 site, and compared it to parental RRV-T48 and to RRV-T48A532V, SINVI538 and SINVT538 harboring different substitutions in the same region. A534V substitution resulted in impaired processing of RRV nonstructural polyprotein and in elevated production of replicase-generated pathogen-associated molecular pattern (PAMP) RNAs that induce expression of type I IFN. Both A532V and A534V substitutions affected synthesis of viral RNAs, though the effects of these closely located mutations were drastically different affecting mostly either the viral negative-strand RNA or genomic and subgenomic RNA levels, respectively. Synthesis of PAMP RNAs was also observed for SINV replicase, and it was increased by I538T substitution. In comparison to RRV-T48, RRV-T48A534V was attenuated in vitro and in vivo. Interestingly, when type I IFN-deficient cells and type I IFN receptor-deficient mice were infected with RRV-T48 or RRV-T48A534V, differences between these viruses were no longer apparent. Compared to RRV-T48, RRV-T48A534V infection was associated with increased upregulation of type I IFN signaling proteins. We demonstrate novel mechanisms by which the A534V mutation affect viral nonstructural polyprotein processing that can impact PAMP RNA production, type I IFN induction/sensitivity, and disease. This study gives further insight into mechanisms of type I IFN modulation by the medically important alphaviruses Ross River virus (RRV) and Sindbis virus (SINV). By characterizing attenuated RRV mutants, the crucial role of amino acid residues in P1 and P3 positions (the first and third amino acid residues preceding the scissile bond) of the cleavage site between nsP1 and nsP2 regions was highlighted. The study uncovers a unique relationship between alphavirus nonstructural polyprotein processing, RNA replication, production of different types of pathogen-associated molecular pattern (PAMP) RNAs, type I IFN induction, and disease pathogenesis. This study also highlights the importance of the host innate immune response in RRV infections. The viral determinants of type I IFN modulation provide potential drug targets for clinical treatment of alphaviral disease and offer new approaches for rational attenuation of alphaviruses for construction of vaccine candidates.
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21
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The Methyltransferase-Like Domain of Chikungunya Virus nsP2 Inhibits the Interferon Response by Promoting the Nuclear Export of STAT1. J Virol 2018; 92:JVI.01008-18. [PMID: 29925658 DOI: 10.1128/jvi.01008-18] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 06/14/2018] [Indexed: 12/15/2022] Open
Abstract
Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that has evolved effective mechanisms to counteract the type I interferon (IFN) response. Upon recognition of the virus, cells secrete IFNs, which signal through transmembrane receptors (IFNAR) to phosphorylate STAT proteins (pSTAT). pSTAT dimers are transported into the nucleus by importin-α5 and activate the transcription of IFN-stimulated genes (ISGs), increasing cellular resistance to infection. Subsequently, STAT proteins are shuttled back into the cytoplasm by the exportin CRM1. CHIKV nonstructural protein 2 (nsP2) reduces ISG expression by inhibiting general host cell transcription and by specifically reducing the levels of nuclear pSTAT1 via an unknown mechanism. To systematically examine where nsP2 acts within the JAK/STAT signaling cascade, we used two well-characterized mutants of nsP2, P718S and KR649AA. Both mutations abrogate nsP2's ability to shut off host transcription, but only the KR649AA mutant localizes exclusively to the cytoplasm and no longer specifically inhibits JAK/STAT signaling. These mutant nsP2 proteins did not differentially affect IFNAR expression levels or STAT1 phosphorylation in response to IFNs. Coimmunoprecipitation experiments showed that in the presence of nsP2, STAT1 still effectively bound importin-α5. Chemically blocking CRM1-mediated nuclear export in the presence of nsP2 additionally showed that nuclear translocation of STAT1 is not affected by nsP2. nsP2 putatively has five domains. Redirecting the nsP2 KR649AA mutant or just nsP2's C-terminal methyltransferase-like domain into the nucleus strongly reduced nuclear pSTAT in response to IFN stimulation. This demonstrates that the C-terminal domain of nuclear nsP2 specifically inhibits the IFN response by promoting the nuclear export of STAT1.IMPORTANCE Chikungunya virus is an emerging pathogen associated with large outbreaks on the African, Asian, European, and both American continents. In most patients, infection results in high fever, rash, and incapacitating (chronic) arthralgia. CHIKV effectively inhibits the first line of defense, the innate immune response. As a result, stimulation of the innate immune response with interferons (IFNs) is ineffective as a treatment for CHIKV disease. The IFN response requires an intact downstream signaling cascade called the JAK/STAT signaling pathway, which is effectively inhibited by CHIKV nonstructural protein 2 (nsP2) via an unknown mechanism. The research described here specifies where in the JAK/STAT signaling cascade the IFN response is inhibited and which protein domain of nsP2 is responsible for IFN inhibition. The results illuminate new aspects of antiviral defense and CHIKV counterdefense strategies and will direct the search for novel antiviral compounds.
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Abstract
Interferon alpha/beta (IFN-α/β) is a critical mediator of protection against most viruses, with host survival frequently impossible in its absence. Many studies have investigated the pathways involved in the induction of IFN-α/β after virus infection and the resultant upregulation of antiviral IFN-stimulated genes (ISGs) through IFN-α/β receptor complex signaling. However, other than examining the effects of genetic deletion of induction or effector pathway components, little is known regarding the functionality of these responses in intact hosts and whether host genetic or environmental factors might influence their potency. Here, we demonstrate that the IFN-α/β response against multiple arthropod-vectored viruses, which replicate over a wide temperature range, is extremely sensitive to fluctuations in temperature, exhibiting reduced antiviral efficacy at subnormal cellular temperatures and increased efficacy at supranormal temperatures. The effect involves both IFN-α/β and ISG upregulation pathways with a major aspect of altered potency reflecting highly temperature-dependent transcription of IFN response genes that leads to altered IFN-α/β and ISG protein levels. Discordantly, signaling steps prior to transcription that were examined showed the opposite effect from gene transcription, with potentiation at low temperature and inhibition at high temperature. Finally, we demonstrate that by lowering the temperature of mice, chikungunya arbovirus replication and disease are exacerbated in an IFN-α/β-dependent manner. This finding raises the potential for use of hyperthermia as a therapeutic modality for viral infections and in other contexts such as antitumor therapy. The increased IFN-α/β efficacy at high temperatures may also reflect an innate immune-relevant aspect of the febrile response. The interferon alpha/beta (IFN-α/β) response is a first-line innate defense against arthropod-borne viruses (arboviruses). Arboviruses, such as chikungunya virus (CHIKV), can infect cells and replicate across a wide temperature range due to their replication in both mammalian/avian and arthropod hosts. Accordingly, these viruses can cause human disease in tissues regularly exposed to temperatures below the normal mammalian core temperature, 37°C. We questioned whether temperature variation could affect the efficacy of IFN-α/β responses against these viruses and help to explain some aspects of human disease manifestations. We observed that IFN-α/β efficacy was dramatically lower at subnormal temperatures and modestly enhanced at febrile temperatures, with the effects involving altered IFN-α/β response gene transcription but not IFN-α/β pathway signaling. These results provide insight into the functioning of the IFN-α/β response in vivo and suggest that temperature elevation may represent an immune-enhancing therapeutic modality for a wide variety of IFN-α/β-sensitive infections and pathologies.
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Novel inhibitors targeting Venezuelan equine encephalitis virus capsid protein identified using In Silico Structure-Based-Drug-Design. Sci Rep 2017; 7:17705. [PMID: 29255256 PMCID: PMC5735092 DOI: 10.1038/s41598-017-17672-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 11/29/2017] [Indexed: 11/09/2022] Open
Abstract
Therapeutics are currently unavailable for Venezuelan equine encephalitis virus (VEEV), which elicits flu-like symptoms and encephalitis in humans, with an estimated 14% of cases resulting in neurological disease. Here we identify anti-VEEV agents using in silico structure-based-drug-design (SBDD) for the first time, characterising inhibitors that block recognition of VEEV capsid protein (C) by the host importin (IMP) α/β1 nuclear transport proteins. From an initial screen of 1.5 million compounds, followed by in silico refinement and screening for biological activity in vitro, we identified 21 hit compounds which inhibited IMPα/β1:C binding with IC50s as low as 5 µM. Four compounds were found to inhibit nuclear import of C in transfected cells, with one able to reduce VEEV replication at µM concentration, concomitant with reduced C nuclear accumulation in infected cells. Further, this compound was inactive against a mutant VEEV that lacks high affinity IMPα/β1:C interaction, supporting the mode of its antiviral action to be through inhibiting C nuclear localization. This successful application of SBDD paves the way for lead optimization for VEEV antivirals, and is an exciting prospect to identify inhibitors for the many other viral pathogens of significance that require IMPα/β1 in their infectious cycle.
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Lundberg L, Carey B, Kehn-Hall K. Venezuelan Equine Encephalitis Virus Capsid-The Clever Caper. Viruses 2017; 9:E279. [PMID: 28961161 PMCID: PMC5691631 DOI: 10.3390/v9100279] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 09/23/2017] [Accepted: 09/26/2017] [Indexed: 01/13/2023] Open
Abstract
Venezuelan equine encephalitis virus (VEEV) is a New World alphavirus that is vectored by mosquitos and cycled in rodents. It can cause disease in equines and humans characterized by a febrile illness that may progress into encephalitis. Like the capsid protein of other viruses, VEEV capsid is an abundant structural protein that binds to the viral RNA and interacts with the membrane-bound glycoproteins. It also has protease activity, allowing cleavage of itself from the growing structural polypeptide during translation. However, VEEV capsid protein has additional nonstructural roles within the host cell functioning as the primary virulence factor for VEEV. VEEV capsid inhibits host transcription and blocks nuclear import in mammalian cells, at least partially due to its complexing with the host CRM1 and importin α/β1 nuclear transport proteins. VEEV capsid also shuttles between the nucleus and cytoplasm and is susceptible to inhibitors of nuclear trafficking, making it a promising antiviral target. Herein, the role of VEEV capsid in viral replication and pathogenesis will be discussed including a comparison to proteins of other alphaviruses.
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Affiliation(s)
- Lindsay Lundberg
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA 20110, USA.
| | - Brian Carey
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA 20110, USA.
| | - Kylene Kehn-Hall
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA 20110, USA.
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Iavarone C, O'hagan DT, Yu D, Delahaye NF, Ulmer JB. Mechanism of action of mRNA-based vaccines. Expert Rev Vaccines 2017; 16:871-881. [PMID: 28701102 DOI: 10.1080/14760584.2017.1355245] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
INTRODUCTION The present review summarizes the growing body of work defining the mechanisms of action of this exciting new vaccine technology that should allow rational approaches in the design of next generation mRNA vaccines. Areas covered: Bio-distribution of mRNA, localization of antigen production, role of the innate immunity, priming of the adaptive immune response, route of administration and effects of mRNA delivery systems. Expert commentary: In the last few years, the development of RNA vaccines had a fast growth, the rising number of proof will enable rational approaches to improving the effectiveness and safety of this modern class of medicine.
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Affiliation(s)
| | | | - Dong Yu
- a GSK Vaccines , Rockville , MD , USA
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Trobaugh DW, Klimstra WB. Alphaviruses suppress host immunity by preventing myeloid cell replication and antagonizing innate immune responses. Curr Opin Virol 2017; 23:30-34. [PMID: 28288385 DOI: 10.1016/j.coviro.2017.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 02/10/2017] [Accepted: 02/16/2017] [Indexed: 12/21/2022]
Abstract
Alphaviruses are medically important mosquito-borne viruses that cause a range of diseases in humans from febrile illness to arthritis or encephalitis. The innate immune response functions to suppress virus replication through upregulation of antiviral molecules and contributes to development of the adaptive immune response. Myeloid cells act as master regulators of virus infection by initiating both the innate and adaptive immune responses. Alphaviruses are capable of antagonizing individual components of these responses to increase replicative fitness in vivo. However, recently, studies have demonstrated that some alphaviruses avoid myeloid cell replication altogether to achieve a similar effect. In this review, we summarize how alphaviruses evade myeloid cell infection and individual inductive mechanisms, thereby limiting the activation of the innate immune response.
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Affiliation(s)
- Derek W Trobaugh
- Center for Vaccine Research, Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15261, United States
| | - William B Klimstra
- Center for Vaccine Research, Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15261, United States.
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Lundberg L, Pinkham C, de la Fuente C, Brahms A, Shafagati N, Wagstaff KM, Jans DA, Tamir S, Kehn-Hall K. Selective Inhibitor of Nuclear Export (SINE) Compounds Alter New World Alphavirus Capsid Localization and Reduce Viral Replication in Mammalian Cells. PLoS Negl Trop Dis 2016; 10:e0005122. [PMID: 27902702 PMCID: PMC5130180 DOI: 10.1371/journal.pntd.0005122] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 10/21/2016] [Indexed: 01/28/2023] Open
Abstract
The capsid structural protein of the New World alphavirus, Venezuelan equine encephalitis virus (VEEV), interacts with the host nuclear transport proteins importin α/β1 and CRM1. Novel selective inhibitor of nuclear export (SINE) compounds, KPT-185, KPT-335 (verdinexor), and KPT-350, target the host's primary nuclear export protein, CRM1, in a manner similar to the archetypical inhibitor Leptomycin B. One major limitation of Leptomycin B is its irreversible binding to CRM1; which SINE compounds alleviate because they are slowly reversible. Chemically inhibiting CRM1 with these compounds enhanced capsid localization to the nucleus compared to the inactive compound KPT-301, as indicated by immunofluorescent confocal microscopy. Differences in extracellular versus intracellular viral RNA, as well as decreased capsid in cell free supernatants, indicated the inhibitors affected viral assembly, which led to a decrease in viral titers. The decrease in viral replication was confirmed using a luciferase-tagged virus and through plaque assays. SINE compounds had no effect on VEEV TC83_Cm, which encodes a mutated form of capsid that is unable to enter the nucleus. Serially passaging VEEV in the presence of KPT-185 resulted in mutations within the nuclear localization and nuclear export signals of capsid. Finally, SINE compound treatment also reduced the viral titers of the related eastern and western equine encephalitis viruses, suggesting that CRM1 maintains a common interaction with capsid proteins across the New World alphavirus genus.
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Affiliation(s)
- Lindsay Lundberg
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Chelsea Pinkham
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Cynthia de la Fuente
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Ashwini Brahms
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Nazly Shafagati
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Kylie M. Wagstaff
- Nuclear Signaling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - David A. Jans
- Nuclear Signaling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Sharon Tamir
- Karyopharm Therapeutics Inc., Massachusetts, United States of America
| | - Kylene Kehn-Hall
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
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Kulkarni A, Ganesan P, O'Donnell LA. Interferon Gamma: Influence on Neural Stem Cell Function in Neurodegenerative and Neuroinflammatory Disease. Clin Med Insights Pathol 2016; 9:9-19. [PMID: 27774000 PMCID: PMC5065109 DOI: 10.4137/cpath.s40497] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 09/05/2016] [Accepted: 09/07/2016] [Indexed: 01/05/2023] Open
Abstract
Interferon-gamma (IFNγ), a pleiotropic cytokine, is expressed in diverse neurodegenerative and neuroinflammatory conditions. Its protective mechanisms are well documented during viral infections in the brain, where IFNγ mediates non-cytolytic viral control in infected neurons. However, IFNγ also plays both protective and pathological roles in other central nervous system (CNS) diseases. Of the many neural cells that respond to IFNγ, neural stem/progenitor cells (NSPCs), the only pluripotent cells in the developing and adult brain, are often altered during CNS insults. Recent studies highlight the complex effects of IFNγ on NSPC activity in neurodegenerative diseases. However, the mechanisms that mediate these effects, and the eventual outcomes for the host, are still being explored. Here, we review the effects of IFNγ on NSPC activity during different pathological insults. An improved understanding of the role of IFNγ would provide insight into the impact of immune responses on the progression and resolution of neurodegenerative diseases.
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Affiliation(s)
- Apurva Kulkarni
- Mylan School of Pharmacy and the Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Priya Ganesan
- Mylan School of Pharmacy and the Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Lauren A O'Donnell
- Mylan School of Pharmacy and the Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
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Fros JJ, Pijlman GP. Alphavirus Infection: Host Cell Shut-Off and Inhibition of Antiviral Responses. Viruses 2016; 8:v8060166. [PMID: 27294951 PMCID: PMC4926186 DOI: 10.3390/v8060166] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 06/01/2016] [Accepted: 06/07/2016] [Indexed: 12/18/2022] Open
Abstract
Alphaviruses cause debilitating disease in humans and animals and are transmitted by blood-feeding arthropods, typically mosquitoes. With a traditional focus on two models, Sindbis virus and Semliki Forest virus, alphavirus research has significantly intensified in the last decade partly due to the re-emergence and dramatic expansion of chikungunya virus in Asia, Europe, and the Americas. As a consequence, alphavirus–host interactions are now understood in much more molecular detail, and important novel mechanisms have been elucidated. It has become clear that alphaviruses not only cause a general host shut-off in infected vertebrate cells, but also specifically suppress different host antiviral pathways using their viral nonstructural proteins, nsP2 and nsP3. Here we review the current state of the art of alphavirus host cell shut-off of viral transcription and translation, and describe recent insights in viral subversion of interferon induction and signaling, the unfolded protein response, and stress granule assembly.
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Affiliation(s)
- Jelke J Fros
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford OX1 3SY, England, UK.
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen 6700 AB, The Netherlands.
| | - Gorben P Pijlman
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen 6700 AB, The Netherlands.
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Forsyth KS, Eisenlohr LC. Giving CD4+ T cells the slip: viral interference with MHC class II-restricted antigen processing and presentation. Curr Opin Immunol 2016; 40:123-9. [PMID: 27115617 PMCID: PMC4894315 DOI: 10.1016/j.coi.2016.03.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 03/08/2016] [Indexed: 01/18/2023]
Abstract
Activation of CD4+ T cells through interactions with peptides bound to Major Histocompatibility Complex Class II (MHC-II) molecules is a crucial step in clearance of most pathogens. Consequently, many viruses have evolved ways of blocking this aspect of adaptive immunity, from specific targeting of processing and presentation components to modulation of signaling pathways that regulate peptide presentation in addition to many other host defense mechanisms. Such cases of interference are far less common compared to what has been elucidated in MHC-I processing and presentation. This may be attributable in part to the complexity of MHC-II antigen processing, the scope of which is only now coming to light.
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Affiliation(s)
- Katherine S Forsyth
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Laurence C Eisenlohr
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States; Department of Pathology and Laboratory Medicine at the Children's Hospital of Philadelphia Research Institute, Philadelphia, PA, United States.
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31
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Patent highlights: December 2015-January 2016. Pharm Pat Anal 2016; 5:147-53. [PMID: 27088860 DOI: 10.4155/ppa-2016-0009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A snapshot of noteworthy recent developments in the patent literature of relevance to pharmaceutical and medical research and development.
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MicroRNA-Attenuated Clone of Virulent Semliki Forest Virus Overcomes Antiviral Type I Interferon in Resistant Mouse CT-2A Glioma. J Virol 2015; 89:10637-47. [PMID: 26269187 DOI: 10.1128/jvi.01868-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 08/04/2015] [Indexed: 01/29/2023] Open
Abstract
UNLABELLED Glioblastoma is a terminal disease with no effective treatment currently available. Among the new therapy candidates are oncolytic viruses capable of selectively replicating in cancer cells, causing tumor lysis and inducing adaptive immune responses against the tumor. However, tumor antiviral responses, primarily mediated by type I interferon (IFN-I), remain a key problem that severely restricts viral replication and oncolysis. We show here that the Semliki Forest virus (SFV) strain SFV4, which causes lethal encephalitis in mice, is able to infect and replicate independent of the IFN-I defense in mouse glioblastoma cells and cell lines originating from primary human glioblastoma patient samples. The ability to tolerate IFN-I was retained in SFV4-miRT124 cells, a derivative cell line of strain SFV4 with a restricted capacity to replicate in neurons due to insertion of target sites for neuronal microRNA 124. The IFN-I tolerance was associated with the viral nsp3-nsp4 gene region and distinct from the genetic loci responsible for SFV neurovirulence. In contrast to the naturally attenuated strain SFV A7(74) and its derivatives, SFV4-miRT124 displayed increased oncolytic potency in CT-2A murine astrocytoma cells and in the human glioblastoma cell lines pretreated with IFN-I. Following a single intraperitoneal injection of SFV4-miRT124 into C57BL/6 mice bearing CT-2A orthotopic gliomas, the virus homed to the brain and was amplified in the tumor, resulting in significant tumor growth inhibition and improved survival. IMPORTANCE Although progress has been made in development of replicative oncolytic viruses, information regarding their overall therapeutic potency in a clinical setting is still lacking. This could be at least partially dependent on the IFN-I sensitivity of the viruses used. Here, we show that the conditionally replicating SFV4-miRT124 virus shares the IFN-I tolerance of the pathogenic wild-type SFV, thereby allowing efficient targeting of a glioma that is refractory to naturally attenuated therapy vector strains sensitive to IFN-I. This is the first evidence of orthotopic syngeneic mouse glioma eradication following peripheral alphavirus administration. Our findings indicate a clear benefit in harnessing the wild-type virus replicative potency in development of next-generation oncolytic alphaviruses.
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Wu JQH. Virulence determinants of New World alphaviruses and broad-acting therapeutic strategies. Future Virol 2015. [DOI: 10.2217/fvl.15.8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
ABSTRACT New World alphaviruses of eastern equine encephalitis virus (EEEV), western equine encephalitis virus (WEEV) and Venezuelan equine encephalitis virus (VEEV) are endemic in North and South America, and infect humans and equine through mosquitoes. In addition, these viruses are highly infectious when aerosolized, making them potential biowarfare and bioterrorism agents. Currently, no approved vaccines or drugs are available for prevention and treatment. Extensive studies have been carried out to understand molecular mechanisms of virulence among New World alphaviruses. This review will focus on virus-encoded, interferon antagonizing proteins which play major role in determination of virulence of New World alphaviruses. Understanding of molecular mechanism of these proteins will shed light on development of broad-acting antivirals against New World alphaviruses.
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Xu C, Evensen Ø, Munang'andu HM. De novo assembly and transcriptome analysis of Atlantic salmon macrophage/dendritic-like TO cells following type I IFN treatment and Salmonid alphavirus subtype-3 infection. BMC Genomics 2015; 16:96. [PMID: 25765343 PMCID: PMC4337061 DOI: 10.1186/s12864-015-1302-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 01/29/2015] [Indexed: 12/23/2022] Open
Abstract
Background Interferons (IFN) are cytokines secreted by vertebrate cells involved in activation of signaling pathways that direct the synthesis of antiviral genes. To gain a global understanding of antiviral genes induced by type I IFNs in salmonids, we used RNA-seq to characterize the transcriptomic changes induced by type I IFN treatment and salmon alphavirus subtype 3 (SAV-3) infection in TO-cells, a macrophage/dendritic like cell-line derived from Atlantic salmon (Salmo salar L) head kidney leukocytes. Results More than 23 million reads generated by RNA-seq were de novo assembled into 58098 unigenes used to generate a total of 3149 and 23289 differentially expressed genes (DEGs) from TO-cells exposed to type I IFN treatment and SAV-3 infection, respectively. Although the DEGs were classified into genes associated with biological processes, cellular components and molecular function based on gene ontology classification, transcriptomic changes reported here show upregulation of genes belonging to the canonical type I IFN signaling pathways together with a broad spectrum of antiviral genes that block virus replication in host cells. In addition, the transcriptome shows a profile of genes associated with apoptosis as well as genes that activate adaptive immunity. Further, our findings show that the profile of genes expressed by TO-cells is comparable to orthologous genes expressed by mammalian macrophages and dendritic cells in response to type I IFNs. Twenty DEGs randomly selected for qRT-PCR confirmed the validity of the transcriptomic changes detected by RNA-seq by showing that the genes upregulated by RNA-seq were also upregulated by qRT-PCR and that genes downregulated by RNA-seq were also downregulated by qRT-PCR. Conclusions The de novo assembled transcriptome presented here provides a global description of genes induced by type I IFNs in TO-cells that could serve as a repository for future studies in fish cells. Transcriptome analysis shows that a large proportion of IFN genes expressed in this study are comparable to IFNs genes expressed in mammalia. In addition, the study shows that SAV-3 is a potent inducer of type I IFNs and that the responses it induces in TO-cells could serve as a model for studying IFN responses in salmonids.
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Affiliation(s)
- Cheng Xu
- Faculty of Veterinary Medicine and Biosciences, Department of Basic Sciences and Aquatic Medicine, Section of Aquatic Medicine and Nutrition, Norwegian University of Life Sciences, P.O. Box 8146, Dep. NO-0033, Oslo, Norway.
| | - Øystein Evensen
- Faculty of Veterinary Medicine and Biosciences, Department of Basic Sciences and Aquatic Medicine, Section of Aquatic Medicine and Nutrition, Norwegian University of Life Sciences, P.O. Box 8146, Dep. NO-0033, Oslo, Norway.
| | - Hetron Mweemba Munang'andu
- Faculty of Veterinary Medicine and Biosciences, Department of Basic Sciences and Aquatic Medicine, Section of Aquatic Medicine and Nutrition, Norwegian University of Life Sciences, P.O. Box 8146, Dep. NO-0033, Oslo, Norway.
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Mutations conferring a noncytotoxic phenotype on chikungunya virus replicons compromise enzymatic properties of nonstructural protein 2. J Virol 2014; 89:3145-62. [PMID: 25552719 DOI: 10.1128/jvi.03213-14] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Chikungunya virus (CHIKV) (genus Alphavirus) has a positive-sense RNA genome. CHIKV nonstructural protein 2 (nsP2) proteolytically processes the viral nonstructural polyprotein, possesses nucleoside triphosphatase (NTPase), RNA triphosphatase, and RNA helicase activities, and induces cytopathic effects in vertebrate cells. Although alphaviral nsP2 mutations can result in a noncytotoxic phenotype, the effects of such mutations on nsP2 enzymatic activities are not well understood. In this study, we introduced a P718G (PG) mutation and selected for additional mutations in CHIKV nsP2 that resulted in a CHIKV replicon with a noncytotoxic phenotype in BHK-21 cells. Combinations of PG and either an E117K (EK) substitution or a GEEGS sequence insertion after residue T647 (5A) markedly reduced RNA synthesis; however, neither PG nor 5A prevented nsP2 nuclear translocation. Introducing PG into recombinant nsP2 inhibited proteolytic cleavage of nsP1/nsP2 and nsP3/nsP4 sites, reduced GTPase and RNA helicase activities, and abolished RNA stimulation of GTPase activity. 5A and EK modulated the effects of PG. However, only the RNA helicase activity of nsP2 was reduced by both of these mutations, suggesting that defects in this activity may be linked to a noncytotoxic phenotype. These results increase our understanding of the molecular basis for the cytotoxicity that accompanies alphaviral replication. Furthermore, adaptation of the CHIKV replicon containing both 5A and PG allowed the selection of a CHIKV replicon with adaptive mutations in nsP1 and nsP3 that enable persistence in human cell line. Such cell lines represent valuable experimental systems for discovering host factors and for screening inhibitors of CHIKV replication at lower biosafety levels. IMPORTANCE CHIKV is a medically important pathogen that causes febrile illness and can cause chronic arthritis. No approved vaccines or antivirals are available for CHIKV. The attenuation of CHIKV is critical to the establishment of experimental systems that can be used to conduct virus replication studies at a lower biosafety level. We applied a functional selection approach to develop, for the first time, a noncytotoxic CHIKV replicon capable of persisting in human cell lines. We anticipate that this safe and efficient research tool will be valuable for screening CHIKV replication inhibitors and for identifying and analyzing host factors involved in viral replication. We also analyzed, from virological and protein biochemistry perspectives, the functional defects caused by mutations conferring noncytotoxic phenotypes; we found that all known enzymatic activities of CHIKV nsP2, as well as its RNA-binding capability, were compromised by these mutations, which led to a reduced capacity for replication.
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Liu Y, Zhang Z, Zhao X, Yu R, Zhang X, Wu S, Liu J, Chi X, Song X, Fu L, Yu Y, Hou L, Chen W. Enterovirus 71 inhibits cellular type I interferon signaling by downregulating JAK1 protein expression. Viral Immunol 2014; 27:267-76. [PMID: 24905060 DOI: 10.1089/vim.2013.0127] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Enterovirus 71 (EV71) infection can cause severe disease and lead to death in children. Recurring outbreaks of EV71 have been reported in several countries. Interferons (IFNs) have been used for decades to treat several types of viral infection, but have a limited ability to inhibit EV71 replication. Herein, we intend to investigate the mechanisms by which EV71 inhibits the cellular type I IFN response. In this study, MRC-5 (human embryonic lung fibroblast) or RD (human rhabdomyosarcoma) cells were infected with EV71, and then treated with or without IFN-α2b. Cells were harvested and analyzed by flow cytometry to determine the level of IFNAR1. Cell lysis were prepared to detect the levels of STAT1, STAT2, phosphorylated STAT1, phosphorylated STAT2, IFNAR1, JAK1, and TYK2 by Western blotting. The phosphorylation of STAT1 and STAT2 induced by IFN were inhibited without significant downregulation of IFNAR1 in EV71-infected cells. The EV71-induced suppression of STAT1 and STAT2 phosphorylation was not rescued by the protein tyrosine phosphatases inhibitor, and was independent of suppressor of cytokine signaling protein 1/3 levels. The phosphorylation of JAK1 and TYK2 were inhibited accompanied by EV71-induced downregulation of JAK1, which occurred at a post-transcriptional level and was proteasome independent. JAK1 expression did not decrease, and IFN-α-stimulated STAT1 and STAT2 phosphorylation were not blocked in HEK293T cells overexpressing the EV71 viral protein 2A or 3C. This study demonstrates that EV71 inhibits the cellular type I IFN antiviral pathway by downregulating JAK1, while the expression of IFNAR1 does not significantly alter in EV71-infected cells. Additionally, the EV71 viral proteins 2A and 3C do not act as antagonists of cellular type I IFN signaling.
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Ong RY, Lum FM, Ng LFP. The fine line between protection and pathology in neurotropic flavivirus and alphavirus infections. Future Virol 2014. [DOI: 10.2217/fvl.14.6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ABSTRACT: Flavivirus and alphavirus are two families of medically important arboviruses known to cause devastating neurologic disease. Exciting knowledge regarding epidemiology, disease and host immune responses are constantly unraveling. In this review, we aim to piece existing knowledge of neurotropic flavi- and alpha-viruses into a general, coherent picture of host–pathogen interactions. Special interest lies in the protective and pathologic host immunity to flavi- and alpha-viral infections, with a strong focus on West Nile virus, Japanese Encephalitis virus and Venezuelan equine encephalitis virus as representatives of their family.
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Affiliation(s)
- Ruo-Yan Ong
- Laboratory of Chikungunya Virus Immunity, Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, #04–06 Immunos Biopolis, 138648, Singapore
| | - Fok-Moon Lum
- Laboratory of Chikungunya Virus Immunity, Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, #04–06 Immunos Biopolis, 138648, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore
| | - Lisa FP Ng
- Laboratory of Chikungunya Virus Immunity, Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, #04–06 Immunos Biopolis, 138648, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore
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Abstract
Alphaviruses are enveloped single-stranded positive sense RNA viruses of the family Togaviridae. The genus alphavirus contains nine viruses, which are of medical, theoretical, or economic importance, and which will be considered. Sindbis virus (SINV) and Semliki Forest (SFV), although of some medical importance, have largely been studied as models of viral pathogenicity. In mice, SINV and SFV infect neurons in the central nervous system and virulent strains induce lethal encephalitis, whereas avirulent strains of SFV induce demyelination. SFV infects the developing foetus and can be teratogenic. Venezuelan Equine Encephalitis virus, Eastern Equine Encephalitis virus, and Western Equine Encephalitis virus can induce encephalitis in horses and humans. They are prevalent in the Americas and are mosquito transmitted. Ross River virus, Chikungunya virus (CHIKV), and O’nyong-nyong virus (ONNV) are prevalent in Australasia, Africa and Asia, and Africa, respectively. ONNV virus is transmitted by Anopheles mosquitoes, while the other alphaviruses are transmitted by culicine mosquitoes. CHIKV has undergone adaptation to a new mosquito host which has increased its host range beyond Africa. Salmonid alphavirus is of economic importance in the farmed salmon and trout industry. It is postulated that future advances in research on alphavirus pathogenicity will come in the field of innate immunity.
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Affiliation(s)
- Gregory J. Atkins
- Department of Microbiology, Moyne Institute, Trinity College, Dublin 2, Ireland
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Kingsolver MB, Huang Z, Hardy RW. Insect antiviral innate immunity: pathways, effectors, and connections. J Mol Biol 2013; 425:4921-36. [PMID: 24120681 DOI: 10.1016/j.jmb.2013.10.006] [Citation(s) in RCA: 213] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 10/01/2013] [Accepted: 10/02/2013] [Indexed: 11/28/2022]
Abstract
Insects are infected by a wide array of viruses some of which are insect restricted and pathogenic, and some of which are transmitted by biting insects to vertebrates. The medical and economic importance of these viruses heightens the need to understand the interaction between the infecting pathogen and the insect immune system in order to develop transmission interventions. The interaction of the virus with the insect host innate immune system plays a critical role in the outcome of infection. The major mechanism of antiviral defense is the small, interfering RNA pathway that responds through the detection of virus-derived double-stranded RNA to suppress virus replication. However, other innate antimicrobial pathways such as Imd, Toll, and Jak-STAT and the autophagy pathway have also been shown to play important roles in antiviral immunity. In this review, we provide an overview of the current understanding of the main insect antiviral pathways and examine recent findings that further our understanding of the roles of these pathways in facilitating a systemic and specific response to infecting viruses.
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Taylor KG, Paessler S. Pathogenesis of Venezuelan equine encephalitis. Vet Microbiol 2013; 167:145-50. [PMID: 23968890 DOI: 10.1016/j.vetmic.2013.07.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 07/03/2013] [Accepted: 07/10/2013] [Indexed: 10/26/2022]
Abstract
Equine encephalids have high mortality rates and represent a significant zoonotic public health threat. Of these the most pathogenic viruses to equids are the alphaviruses in the family Togaviridae. The focus of this review Venezualen equine encephalitis virus (VEEV) has caused the most widespread and recent epidemic outbreaks of disease. Circulation in naturally occuring rodent-mosquito cycles, results in viral spread to both human and equine populations. However, equines develop a high titer viremia and can transmit the virus back to mosquito populations. As such, the early recognition and control of viral infection in equine populations is strongly associated with prevention of epidemic spread of the virus and limiting of disease incidence in human populations. This review will address identification and pathogenesis of VEEV in equids vaccination and treatment options, and current research for drug and vaccine development.
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Affiliation(s)
- Katherine G Taylor
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77550, United States.
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41
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The C-terminal domain of chikungunya virus nsP2 independently governs viral RNA replication, cytopathicity, and inhibition of interferon signaling. J Virol 2013; 87:10394-400. [PMID: 23864632 DOI: 10.1128/jvi.00884-13] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Alphavirus nonstructural protein 2 (nsP2) has pivotal roles in viral RNA replication, host cell shutoff, and inhibition of antiviral responses. Mutations that individually rendered other alphaviruses noncytopathic were introduced into chikungunya virus nsP2. Results show that (i) nsP2 mutation P718S only in combination with KR649AA or adaptive mutation D711G allowed noncytopathic replicon RNA replication, (ii) prohibiting nsP2 nuclear localization abrogates inhibition of antiviral interferon-induced JAK-STAT signaling, and (iii) nsP2 independently affects RNA replication, cytopathicity, and JAK-STAT signaling.
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42
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Seymour RL, Rossi SL, Bergren NA, Plante KS, Weaver SC. The role of innate versus adaptive immune responses in a mouse model of O'nyong-nyong virus infection. Am J Trop Med Hyg 2013; 88:1170-9. [PMID: 23568285 PMCID: PMC3752819 DOI: 10.4269/ajtmh.12-0674] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 01/01/2013] [Indexed: 01/04/2023] Open
Abstract
O'nyong-nyong virus (ONNV), an alphavirus closely related to chikungunya virus (CHIKV), has caused three major epidemics in Africa since 1959. Both ONNV and CHIKV produce similar syndromes with fever, rash, and debilitating arthralgia. To determine the roles of the innate and adaptive immune responses, we infected different knockout mice with two strains of ONNV (SG650 and MP30). Wild-type, RAG1 KO, and IFNγR KO mice showed no signs of illness or viremia. The STAT1 KO and A129 mice exhibited 50-55% mortality when infected with SG650. Strain SG650 was more virulent in the STAT1 KO and A129 than MP30. Deficiency in interferon α/β signaling (A129 and STAT1 KO) leaves mice susceptible to lethal disease; whereas a deficiency of interferon γ signaling alone had no effect on survival. Our findings highlight the importance of type I interferon in protection against ONNV infection, whereas the adaptive immune system is relatively unimportant in the acute infection.
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Affiliation(s)
- Robert L Seymour
- Institute for Human Infections and Immunity, Center for Tropical Diseases, and Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
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Neurotropic arboviruses induce interferon regulatory factor 3-mediated neuronal responses that are cytoprotective, interferon independent, and inhibited by Western equine encephalitis virus capsid. J Virol 2012. [PMID: 23192868 DOI: 10.1128/jvi.02858-12] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cell-intrinsic innate immune responses mediated by the transcription factor interferon regulatory factor 3 (IRF-3) are often vital for early pathogen control, and effective responses in neurons may be crucial to prevent the irreversible loss of these critical central nervous system cells after infection with neurotropic pathogens. To investigate this hypothesis, we used targeted molecular and genetic approaches with cultured neurons to study cell-intrinsic host defense pathways primarily using the neurotropic alphavirus western equine encephalitis virus (WEEV). We found that WEEV activated IRF-3-mediated neuronal innate immune pathways in a replication-dependent manner, and abrogation of IRF-3 function enhanced virus-mediated injury by WEEV and the unrelated flavivirus St. Louis encephalitis virus. Furthermore, IRF-3-dependent neuronal protection from virus-mediated cytopathology occurred independently of autocrine or paracrine type I interferon activity. Despite being partially controlled by IRF-3-dependent signals, WEEV also disrupted antiviral responses by inhibiting pattern recognition receptor pathways. This antagonist activity was mapped to the WEEV capsid gene, which disrupted signal transduction downstream of IRF-3 activation and was independent of capsid-mediated inhibition of host macromolecular synthesis. Overall, these results indicate that innate immune pathways have important cytoprotective activity in neurons and contribute to limiting injury associated with infection by neurotropic arboviruses.
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An attenuating mutation in a neurovirulent Sindbis virus strain interacts with the IPS-1 signaling pathway in vivo. Virology 2012; 435:269-80. [PMID: 23084425 DOI: 10.1016/j.virol.2012.09.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 08/27/2012] [Accepted: 09/13/2012] [Indexed: 12/24/2022]
Abstract
The AR86 strain of Sindbis virus causes lethal neurologic disease in adult mice. Previous studies have identified a virulence determinant at nonstructural protein (nsP) 1 position 538 that regulates neurovirulence, modulates clearance from the CNS, and interferes with the type I interferon pathway. The studies herein demonstrate that in the absence of type I interferon signaling, the attenuated mutant exhibited equivalent virulence to S300 virus. Furthermore, both S300 and nsP1 T538I viruses displayed similar neurovirulence and replication kinetics in IPS-1-/- mice. TRIF dependent signaling played a modest role in protecting against disease by both S300 and nsP1 T538I, but did not contribute to control of nsP1 T538I replication within the CNS, while MyD88 played no role in the disease process. These results indicate that the control of the nsP1 T538I mutant virus is largely mediated by IPS-1-dependent RLR signaling, with TRIF-dependent TLR signaling also contributing to protection from virus-induced neurologic disease.
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Tonkin DR, Whitmore A, Johnston RE, Barro M. Infected dendritic cells are sufficient to mediate the adjuvant activity generated by Venezuelan equine encephalitis virus replicon particles. Vaccine 2012; 30:4532-42. [PMID: 22531556 DOI: 10.1016/j.vaccine.2012.04.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 03/09/2012] [Accepted: 04/09/2012] [Indexed: 01/09/2023]
Abstract
Replicon particles derived from Venezuelan equine encephalitis virus (VEE) are infectious non-propagating particles which act as a safe and potent systemic, mucosal, and cellular adjuvant when delivered with antigen. VEE and VEE replicon particles (VRP) can target multiple cell types including dendritic cells (DCs). The role of these cell types in VRP adjuvant activity has not been previously evaluated, and for these studies we focused on the contribution of DCs to the response to VRP. By analysis of VRP targeting in the draining lymph node, we found that VRP induced rapid recruitment of TNF-secreting monocyte-derived inflammatory dendritic cells. VRP preferentially infected these inflammatory DCs as well as classical DCs and macrophages, with less efficient infection of other cell types. DC depletion suggested that the interaction of VRP with classical DCs was required for recruitment of inflammatory DCs, induction of high levels of many cytokines, and for stable transport of VRP to the draining lymph node. Additionally, in vitro-infected DCs enhanced antigen-specific responses by CD4 and CD8 T cells. By transfer of VRP-infected DCs into mice we showed that these DCs generated an inflammatory state in the draining lymph node similar to that achieved by VRP injection. Most importantly, VRP-infected DCs were sufficient to establish robust adjuvant activity in mice comparable to that produced by VRP injection. These findings indicate that VRP infect, recruit and activate both classical and inflammatory DCs, and those DCs become mediators of the VRP adjuvant activity.
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Affiliation(s)
- Daniel R Tonkin
- Global Vaccines Inc, 7020 Kit Creek Rd, Ste. 240, PO Box 14827, Research Triangle Park, NC 27709, USA.
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46
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Taylor K, Kolokoltsova O, Patterson M, Poussard A, Smith J, Estes DM, Paessler S. Natural killer cell mediated pathogenesis determines outcome of central nervous system infection with Venezuelan equine encephalitis virus in C3H/HeN mice. Vaccine 2012; 30:4095-105. [PMID: 22525795 DOI: 10.1016/j.vaccine.2012.03.076] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 03/07/2012] [Accepted: 03/25/2012] [Indexed: 10/28/2022]
Abstract
TC83 is a human vaccine with investigational new drug status and is used as a prototype Venezuelan equine encephalitis virus for pathogenesis and antiviral research. Differing from other experimental models, the virus causes high titer infection in the brain and 90-100% mortality in the C3H/HeN murine model. To better characterize the susceptibility to disease development in C3H/HeN mice, we have analyzed the gene transcriptomes and cytokine production in the brains of infected mice. Our analysis indicated the potential importance of natural killer cells in the encephalitic disease development. This paper describes for the first time a pathogenic role for natural killer cells in VEEV encephalitis.
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Affiliation(s)
- Katherine Taylor
- Sealy Center for Vaccine Development, Galveston National Lab, Department of Pathology, University of Texas Medical Branch, Galveston, TX 77550, USA.
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Abstract
Alphaviruses are a group of important human and animal pathogens. They efficiently replicate to high titers in vivo and in many commonly used cell lines of vertebrate origin. They have also evolved effective means of interfering with development of the innate immune response. Nevertheless, most of the alphaviruses are known to induce a type I interferon (IFN) response in vivo. The results of this study demonstrate that the first hours postinfection play a critical role in infection spread and development of the antiviral response. During this window, a balance is struck between virus replication and spread in vertebrate cells and IFN response development. The most important findings are as follows: (i) within the first 2 to 4 h postinfection, alphavirus-infected cells become unable to respond to IFN-β, and this occurs before the virus-induced decrease in STAT1 phosphorylation in response to IFN treatment. (ii) Most importantly, very low, subprotective doses of IFN-β, which do not induce the antiviral response in uninfected cells, have a very strong stimulatory effect on the cells' ability to express type I IFN and activate interferon-stimulated genes during subsequent infection with Sindbis virus (SINV). (iii) Small changes in SINV nsP2 protein affect its ability to inhibit cellular transcription and IFN release. Thus, the balance between type I IFN induction and the ability of the virus to develop further rounds of infection is determined in the first few hours of virus replication, when only low numbers of cells and infectious virus are involved.
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Gardner CL, Burke CW, Higgs ST, Klimstra WB, Ryman KD. Interferon-alpha/beta deficiency greatly exacerbates arthritogenic disease in mice infected with wild-type chikungunya virus but not with the cell culture-adapted live-attenuated 181/25 vaccine candidate. Virology 2012; 425:103-12. [PMID: 22305131 DOI: 10.1016/j.virol.2011.12.020] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 09/12/2011] [Accepted: 12/31/2011] [Indexed: 11/29/2022]
Abstract
In humans, chikungunya virus (CHIKV) infection causes fever, rash, and acute and persisting polyarthralgia/arthritis associated with joint swelling. We report a new CHIKV disease model in adult mice that distinguishes the wild-type CHIKV-LR strain from the live-attenuated vaccine strain (CHIKV-181/25). Although eight-week old normal mice inoculated in the hind footpad developed no hind limb swelling with either virus, CHIKV-LR replicated in musculoskeletal tissues and caused detectable inflammation. In mice deficient in STAT1-dependent interferon (IFN) responses, CHIKV-LR caused significant swelling of the inoculated and contralateral limbs and dramatic inflammatory lesions, while CHIKV-181/25 vaccine and another arthritogenic alphavirus, Sindbis, failed to induce swelling. IFN responses suppressed CHIKV-LR and CHIKV-181/25 replication equally in dendritic cells in vitro whereas macrophages were refractory to infection independently of STAT1-mediated IFN responses. Glycosaminoglycan (GAG) binding may be a CHIKV vaccine attenuation mechanism as CHIKV-LR infectivity was not dependent upon GAG, while CHIKV-181/25 was highly dependent.
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Affiliation(s)
- Christina L Gardner
- Center for Vaccine Research and Dept. of Microbiology & Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA
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49
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Koehler JW, Dupuy LC, Garrison AR, Beitzel BF, Richards MJ, Ripoll DR, Wallqvist A, Teh SY, Vaewhongs AA, Vojdani FS, Padgett HS, Schmaljohn CS. Novel plant-derived recombinant human interferons with broad spectrum antiviral activity. Antiviral Res 2011; 92:461-9. [PMID: 22020161 PMCID: PMC9628711 DOI: 10.1016/j.antiviral.2011.10.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 09/27/2011] [Accepted: 10/07/2011] [Indexed: 02/03/2023]
Abstract
Type I interferons (IFNs) are potent mediators of the innate immune response to viral infection. IFNs released from infected cells bind to a receptor (IFNAR) on neighboring cells, triggering signaling cascades that limit further infection. Subtle variations in amino acids can alter IFNAR binding and signaling outcomes. We used a new gene crossbreeding method to generate hybrid, type I human IFNs with enhanced antiviral activity against four dissimilar, highly pathogenic viruses. Approximately 1400 novel IFN genes were expressed in plants, and the resultant IFN proteins were screened for antiviral activity. Comparing the gene sequences of a final set of 12 potent IFNs to those of parent genes revealed strong selection pressures at numerous amino acids. Using three-dimensional models based on a recently solved experimental structure of IFN bound to IFNAR, we show that many but not all of the amino acids that were highly selected for are predicted to improve receptor binding.
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Key Words
- ifns, interferons
- ifnar, interferon-α receptor
- veev, venezuelan equine encephalitis virus
- rvfv, rift valley fever virus
- ebov, ebola virus
- mpxv, monkeypox virus
- grammr™, genetic reassortment by mismatch resolution
- bsa, bovine serum albumin
- gfp, green fluorescent protein
- pspp, protein structure prediction pipeline
- pdb, protein data bank
- type i interferons
- ebola virus
- rift valley fever virus
- venezuelan equine encephalitis virus
- monkeypox virus
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Affiliation(s)
- Jeffrey W Koehler
- U.S. Army Medical Research Institute of Infectious Diseases, Virology Division, Fort Detrick, MD 21702, USA
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Ren J, Kolli D, Liu T, Xu R, Garofalo RP, Casola A, Bao X. Human metapneumovirus inhibits IFN-β signaling by downregulating Jak1 and Tyk2 cellular levels. PLoS One 2011; 6:e24496. [PMID: 21949722 PMCID: PMC3176284 DOI: 10.1371/journal.pone.0024496] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 08/11/2011] [Indexed: 11/19/2022] Open
Abstract
Human metapneumovirus (hMPV), a leading cause of respiratory tract infections in infants, inhibits type I interferon (IFN) signaling by an unidentified mechanism. In this study, we showed that infection of airway epithelial cells with hMPV decreased cellular level of Janus tyrosine kinase (Jak1) and tyrosine kinase 2 (Tyk2), due to enhanced proteosomal degradation and reduced gene transcription. In addition, hMPV infection also reduced the surface expression of type I IFN receptor (IFNAR). These inhibitory mechanisms are different from the ones employed by respiratory syncytial virus (RSV), which does not affect Jak1, Tyk2 or IFNAR expression, but degrades downstream signal transducer and activator of transcription proteins 2 (STAT2), although both viruses are pneumoviruses belonging to the Paramyxoviridae family. Our study identifies a novel mechanism by which hMPV inhibits STAT1 and 2 activation, ultimately leading to viral evasion of host IFN responses.
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Affiliation(s)
- Junping Ren
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
| | - Deepthi Kolli
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
| | - Tianshuang Liu
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
| | - Renling Xu
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
| | - Roberto P. Garofalo
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
- Departments of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
| | - Antonella Casola
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
- Departments of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
- * E-mail: (AC); (XB)
| | - Xiaoyong Bao
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Galveston, Texas, United States of America
- * E-mail: (AC); (XB)
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