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Zhou CM, Jiang ZZ, Liu N, Yu XJ. Current insights into human pathogenic phenuiviruses and the host immune system. Virulence 2024; 15:2384563. [PMID: 39072499 PMCID: PMC11290763 DOI: 10.1080/21505594.2024.2384563] [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: 05/22/2024] [Revised: 07/09/2024] [Accepted: 07/18/2024] [Indexed: 07/30/2024] Open
Abstract
Phenuiviruses are a class of segmented negative-sense single-stranded RNA viruses, typically consisting of three RNA segments that encode four distinct proteins. The emergence of pathogenic phenuivirus strains, such as Rift Valley fever phlebovirus (RVFV) in sub-Saharan Africa, Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV) in East and Southeast Asia, and Heartland Virus (HRTV) in the United States has presented considerable challenges to global public health in recent years. The innate immune system plays a crucial role as the initial defense mechanism of the host against invading pathogens. In addition to continued research aimed at elucidating the epidemiological characteristics of phenuivirus, significant advancements have been made in investigating its viral virulence factors (glycoprotein, non-structural protein, and nucleoprotein) and potential host-pathogen interactions. Specifically, efforts have focused on understanding mechanisms of viral immune evasion, viral assembly and egress, and host immune networks involving immune cells, programmed cell death, inflammation, nucleic acid receptors, etc. Furthermore, a plethora of technological advancements, including metagenomics, metabolomics, single-cell transcriptomics, proteomics, gene editing, monoclonal antibodies, and vaccines, have been utilized to further our understanding of phenuivirus pathogenesis and host immune responses. Hence, this review aims to provide a comprehensive overview of the current understanding of the mechanisms of host recognition, viral immune evasion, and potential therapeutic approaches during human pathogenic phenuivirus infections focusing particularly on RVFV and SFTSV.
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Affiliation(s)
- Chuan-Min Zhou
- Gastrointestinal Disease Diagnosis and Treatment Center, The First Hospital of Hebei Medical University, Shijiazhuang, China
- Department of General Surgery, Hebei Key Laboratory of Colorectal Cancer Precision Diagnosis and Treatment, The First Hospital of Hebei Medical University, Shijiazhuang, China
- Central Laboratory, The First Hospital of Hebei Medical University, Shijiazhuang, China
| | - Ze-Zheng Jiang
- State Key Laboratory of Virology, School of Public Health, Wuhan University, Wuhan, China
| | - Ning Liu
- Department of Quality and Operations Management, The First Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xue-Jie Yu
- State Key Laboratory of Virology, School of Public Health, Wuhan University, Wuhan, China
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2
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Freeman TL, McElroy AK. Laboratory Animal Models for Rift Valley Fever Virus Disease. Methods Mol Biol 2024; 2824:425-445. [PMID: 39039428 DOI: 10.1007/978-1-0716-3926-9_27] [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] [Indexed: 07/24/2024]
Abstract
Rift Valley fever virus (RVFV) is an arboviral pathogen of clinical and agricultural relevance. The ongoing development of targeted RVFV prophylactics and therapeutics is overwhelmingly dependent on animal models due to both natural, that is, sporadic outbreaks, and structural, for example, underresourcing of endemic regions, limitations in accessing human patient samples and cohorts. Elucidating mechanisms of viral pathogenesis and testing therapeutics is further complicated by the diverse manifestations of RVFV disease and the heterogeneity of the host response to infection. In this chapter, we describe major clinical manifestations of RVFV infection and discuss the laboratory animal models used to study each.
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Affiliation(s)
- Tracey L Freeman
- University of Pittsburgh School of Medicine, Department of Pediatrics, Division of Pediatric Infectious Disease, Pittsburgh, PA, USA
- University of Pittsburgh Center for Vaccine Research, Pittsburgh, PA, USA
| | - Anita K McElroy
- University of Pittsburgh School of Medicine, Department of Pediatrics, Division of Pediatric Infectious Disease, Pittsburgh, PA, USA.
- University of Pittsburgh Center for Vaccine Research, Pittsburgh, PA, USA.
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3
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Terasaki K, Narayanan K, Makino S. Identification of a 1.4-kb-Long Sequence Located in the nsp12 and nsp13 Coding Regions of SARS-CoV-2 Genomic RNA That Mediates Efficient Viral RNA Packaging. J Virol 2023:e0065923. [PMID: 37367225 PMCID: PMC10373556 DOI: 10.1128/jvi.00659-23] [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: 05/10/2023] [Accepted: 06/09/2023] [Indexed: 06/28/2023] Open
Abstract
The specific packaging of the viral RNA genome into virus particles is an essential step in the replication cycle of coronaviruses (CoVs). Using a single-cycle, replicable severe acute respiratory syndrome CoV-2 (SARS-CoV-2) mutant, we demonstrated the preferential packaging of the SARS-CoV-2 genomic RNA into purified virus particles. Furthermore, based on the sequence of an efficiently packaged defective interfering RNA of SARS-CoV, a closely related CoV, that was generated after serial passages of SARS-CoV in cell culture, we designed a series of replication-competent SARS-CoV-2 minigenome RNAs to identify the specific viral RNA region that is important for SARS-CoV-2 RNA packaging into virus particles. We showed that a 1.4-kb-long sequence, derived from the nsp12 and nsp13 coding regions of the SARS-CoV-2 genomic RNA, is required for the efficient packaging of SARS-CoV-2 minigenome RNA into SARS-CoV-2 particles. In addition, we also showed that the presence of possibly the entire 1.4-kb-long sequence is important for the efficient packaging of SARS-CoV-2 RNA. Our findings highlight the differences between the RNA packaging sequence identified in SARS-CoV-2, a Sarbecovirus, and the packaging signal of mouse hepatitis virus (MHV), an Embecovirus, which is a 95-nt-long sequence located at the nsp15 coding region of MHV genomic RNA. Collectively, our data imply that both the location and the sequence/structural features of the RNA element(s) that drives the selective and efficient packaging of viral genomic RNA are not conserved among the subgenera Embecovirus and Sarbecovirus within the Betacoronavirus genus. IMPORTANCE Elucidating the mechanism of SARS-CoV-2 RNA packaging into virus particles is important for the rational design of antiviral drugs that inhibit this vital step in the replication cycle of CoVs. However, our knowledge about the RNA packaging mechanism in SARS-CoV-2, including the identification of the viral RNA region important for SARS-CoV-2 RNA packaging, is limited, primarily due to the logistical challenges of handing SARS-CoV-2 in biosafety level 3 (BSL3) facilities. Our study, using a single-cycle, replicable SARS-CoV-2 mutant, which can be handled in a BSL2 lab, demonstrated the preferential packaging of full-length SARS-CoV-2 genomic RNA into virus particles and identified a specific 1.4-kb-long RNA region in SARS-CoV-2 genomic RNA that is required for the efficient packaging of SARS-CoV-2 RNA into virus particles. The information generated in our study could be valuable for clarifying the mechanisms of SARS-CoV-2 RNA packaging and for the development of targeted therapeutics against SARS-CoV-2 and other related CoVs.
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Affiliation(s)
- Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, USA
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Texas, USA
| | - Krishna Narayanan
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, USA
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, USA
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Texas, USA
- Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, USA
- UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, USA
- The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, Texas, USA
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Godbold GD, Hewitt FC, Kappell AD, Scholz MB, Agar SL, Treangen TJ, Ternus KL, Sandbrink JB, Koblentz GD. Improved understanding of biorisk for research involving microbial modification using annotated sequences of concern. Front Bioeng Biotechnol 2023; 11:1124100. [PMID: 37180048 PMCID: PMC10167326 DOI: 10.3389/fbioe.2023.1124100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/11/2023] [Indexed: 05/15/2023] Open
Abstract
Regulation of research on microbes that cause disease in humans has historically been focused on taxonomic lists of 'bad bugs'. However, given our increased knowledge of these pathogens through inexpensive genome sequencing, 5 decades of research in microbial pathogenesis, and the burgeoning capacity of synthetic biologists, the limitations of this approach are apparent. With heightened scientific and public attention focused on biosafety and biosecurity, and an ongoing review by US authorities of dual-use research oversight, this article proposes the incorporation of sequences of concern (SoCs) into the biorisk management regime governing genetic engineering of pathogens. SoCs enable pathogenesis in all microbes infecting hosts that are 'of concern' to human civilization. Here we review the functions of SoCs (FunSoCs) and discuss how they might bring clarity to potentially problematic research outcomes involving infectious agents. We believe that annotation of SoCs with FunSoCs has the potential to improve the likelihood that dual use research of concern is recognized by both scientists and regulators before it occurs.
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Affiliation(s)
| | | | | | | | - Stacy L. Agar
- Signature Science, LLC, Charlottesville, VA, United States
| | - Todd J. Treangen
- Department of Computer Science, Rice University, Houston, TX, United States
| | | | - Jonas B. Sandbrink
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Gregory D. Koblentz
- Schar School of Policy and Government, George Mason University, Arlington, VA, United States
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Qin Y, Zhang P, Deng S, Guo W, Zhang M, Liu H, Qiu R, Yao L. Red-grouper nervous necrosis virus B1 protein inhibits fish IFN response by targeting Ser5-phosphorylated RNA polymerase II to promote viral replication. FISH & SHELLFISH IMMUNOLOGY 2023; 134:108578. [PMID: 36740084 DOI: 10.1016/j.fsi.2023.108578] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 01/15/2023] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
Nervous necrosis virus (NNV) could infect more than 200 fish species worldwide, with almost 100% mortality in affected larvae and juvenile fish. Among different genotypes of NNV, the red-grouper nervous necrosis virus (RGNNV) genotype is the most widely reported with the highest number of susceptible species. Interferon (IFN) is a crucial antiviral cytokine and RGNNV needs to develop some efficient strategies to resist host IFN-stimulated antiviral immune. Although considerable researches on RGNNV, whether RGNNV B1 protein participates in regulating the host's IFN response remains unknown. Here, we reported that B1 protein acted as a transcript inhibition factor to suppress fish IFN production. We firstly found that ectopic expression of B1 protein significantly decreased IFN and IFN-stimulated genes (ISGs) mRNA levels and IFNφ1 promoter activity induced by polyinosinic:polycytidylic acid [poly (I:C)]. Further studies showed that B1 protein inhibited the IFNφ1 promoter activity stimulated by the key RIG-I-like receptors (RLRs) factors, including MDA5, MAVS, TBK1, IRF3, and IRF7 and decreased their protein levels. Moreover, B1 protein significantly inhibited the activity of constitutively active cytomegalovirus (CMV) promoter, which suggested that B1 protein was a transcription inhibitor. Western blot indicated that B1 protein decreased the Ser5 phosphorylation of RNA polymerase II (RNAP II) C-terminal domain (CTD). Together, our data demonstrated that RGNNV B1 protein was a host transcript antagonist, which intervened RNAP II Ser5-phosphorylation, inhibiting host IFN response and facilitating RGNNV replication.
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Affiliation(s)
- Yinghui Qin
- College of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang, 473061, China; Key Laboratory of Ecological Security and Collaborative Innovation Centre of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project of Henan Province, Nanyang, 473061, China; Henan Provincal Engineering and Technology Center of Health Products for Livestock and Poultry, Nanyang, 473061, China
| | - Peipei Zhang
- College of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang, 473061, China; Key Laboratory of Ecological Security and Collaborative Innovation Centre of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project of Henan Province, Nanyang, 473061, China; Henan Provincal Engineering and Technology Center of Health Products for Livestock and Poultry, Nanyang, 473061, China
| | - Si Deng
- College of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang, 473061, China; Key Laboratory of Ecological Security and Collaborative Innovation Centre of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project of Henan Province, Nanyang, 473061, China; Henan Provincal Engineering and Technology Center of Health Products for Livestock and Poultry, Nanyang, 473061, China
| | - Wenjing Guo
- College of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang, 473061, China; Key Laboratory of Ecological Security and Collaborative Innovation Centre of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project of Henan Province, Nanyang, 473061, China; Henan Provincal Engineering and Technology Center of Health Products for Livestock and Poultry, Nanyang, 473061, China
| | - Mengfan Zhang
- College of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang, 473061, China; Key Laboratory of Ecological Security and Collaborative Innovation Centre of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project of Henan Province, Nanyang, 473061, China; Henan Provincal Engineering and Technology Center of Health Products for Livestock and Poultry, Nanyang, 473061, China
| | - Haixiang Liu
- College of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang, 473061, China; Key Laboratory of Ecological Security and Collaborative Innovation Centre of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project of Henan Province, Nanyang, 473061, China; Henan Provincal Engineering and Technology Center of Health Products for Livestock and Poultry, Nanyang, 473061, China
| | - Reng Qiu
- College of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang, 473061, China; Key Laboratory of Ecological Security and Collaborative Innovation Centre of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project of Henan Province, Nanyang, 473061, China; Henan Provincal Engineering and Technology Center of Health Products for Livestock and Poultry, Nanyang, 473061, China
| | - Lunguang Yao
- College of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang, 473061, China; Key Laboratory of Ecological Security and Collaborative Innovation Centre of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project of Henan Province, Nanyang, 473061, China; Henan Provincal Engineering and Technology Center of Health Products for Livestock and Poultry, Nanyang, 473061, China.
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Nambou K, Anakpa M, Tong YS. Human genes with codon usage bias similar to that of the nonstructural protein 1 gene of influenza A viruses are conjointly involved in the infectious pathogenesis of influenza A viruses. Genetica 2022; 150:97-115. [PMID: 35396627 PMCID: PMC8992787 DOI: 10.1007/s10709-022-00155-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 03/24/2022] [Indexed: 11/27/2022]
Abstract
Molecular mechanisms of the non-structural protein 1 (NS1) in influenza A-induced pathological changes remain ambiguous. This study explored the pathogenesis of human infection by influenza A viruses (IAVs) through identifying human genes with codon usage bias (CUB) similar to NS1 gene of these viruses based on the relative synonymous codon usage (RSCU). CUB of the IAV subtypes H1N1, H3N2, H3N8, H5N1, H5N2, H5N8, H7N9 and H9N2 was analyzed and the correlation of RSCU values of NS1 sequences with those of the human genes was calculated. The CUB of NS1 was uneven and codons ending with A/U were preferred. The ENC-GC3 and neutrality plots suggested natural selection as the main determinant for CUB. The RCDI, CAI and SiD values showed that the viruses had a high degree of adaptability to human. A total of 2155 human genes showed significant RSCU-based correlation (p < 0.05 and r > 0.5) with NS1 coding sequences and was considered as human genes with CUB similar to NS1 gene of IAV subtypes. Differences and similarities in the subtype-specific human protein–protein interaction (PPI) networks and their functions were recorded among IAVs subtypes, indicating that NS1 of each IAV subtype has a specific pathogenic mechanism. Processes and pathways involved in influenza, transcription, immune response and cell cycle were enriched in human gene sets retrieved based on the CUB of NS1 gene of IAV subtypes. The present work may advance our understanding on the mechanism of NS1 in human infections of IAV subtypes and shed light on the therapeutic options.
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Affiliation(s)
- Komi Nambou
- Shenzhen Nambou1 Biotech Company Limited, 998 Wisdom Valley, No. 38-56 Zhenming Road, Guangming District, Shenzhen, 518106, China.
| | - Manawa Anakpa
- Centre d'Informatique et de Calcul, Université de Lomé, Boulevard Gnassingbé Eyadema, 01 B.P. 1515, Lomé, Togo
| | - Yin Selina Tong
- Shenzhen Nambou1 Biotech Company Limited, 998 Wisdom Valley, No. 38-56 Zhenming Road, Guangming District, Shenzhen, 518106, China
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Terasaki K, Kalveram B, Johnson KN, Juelich T, Smith JK, Zhang L, Freiberg AN, Makino S. Rift Valley fever virus 78kDa envelope protein attenuates virus replication in macrophage-derived cell lines and viral virulence in mice. PLoS Negl Trop Dis 2021; 15:e0009785. [PMID: 34516560 PMCID: PMC8460012 DOI: 10.1371/journal.pntd.0009785] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 09/23/2021] [Accepted: 09/02/2021] [Indexed: 12/27/2022] Open
Abstract
Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus with a wide host range including ruminants and humans. RVFV outbreaks have had devastating effects on public health and the livestock industry in African countries. However, there is no approved RVFV vaccine for human use in non-endemic countries and no FDA-approved antiviral drug for RVFV treatment. The RVFV 78kDa protein (P78), which is a membrane glycoprotein, plays a role in virus dissemination in the mosquito host, but its biological role in mammalian hosts remains unknown. We generated an attenuated RVFV MP-12 strain-derived P78-High virus and a virulent ZH501 strain-derived ZH501-P78-High virus, both of which expressed a higher level of P78 and carried higher levels of P78 in the virion compared to their parental viruses. We also generated another MP-12-derived mutant virus (P78-KO virus) that does not express P78. MP-12 and P78-KO virus replicated to similar levels in fibroblast cell lines and Huh7 cells, while P78-High virus replicated better than MP-12 in Vero E6 cells, fibroblast cell lines, and Huh7 cells. Notably, P78-High virus and P78-KO virus replicated less efficiently and more efficiently, respectively, than MP-12 in macrophage cell lines. ZH501-P78-High virus also replicated poorly in macrophage cell lines. Our data further suggest that inefficient binding of P78-High virus to the cells led to inefficient virus internalization, low virus infectivity and reduced virus replication in a macrophage cell line. P78-High virus and P78-KO virus showed lower and higher virulence than MP-12, respectively, in young mice. ZH501-P78-High virus also exhibited lower virulence than ZH501 in mice. These data suggest that high levels of P78 expression attenuate RVFV virulence by preventing efficient virus replication in macrophages. Genetic alteration leading to increased P78 expression may serve as a novel strategy for the attenuation of RVFV virulence and generation of safe RVFV vaccines.
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Affiliation(s)
- Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute of Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail: (KT); (SM)
| | - Birte Kalveram
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Kendra N. Johnson
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Terry Juelich
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jennifer K. Smith
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Lihong Zhang
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Alexander N. Freiberg
- Institute of Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Biodefense and Emerging Infectious Diseases, the University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute of Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Biodefense and Emerging Infectious Diseases, the University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail: (KT); (SM)
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8
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Characterization of the Molecular Interactions That Govern the Packaging of Viral RNA Segments into Rift Valley Fever Phlebovirus Particles. J Virol 2021; 95:e0042921. [PMID: 33952635 DOI: 10.1128/jvi.00429-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Rift Valley fever phlebovirus (RVFV) has a single-stranded, negative-sense RNA genome, consisting of L, M, and S segments. The virion carries two envelope glycoproteins, Gn and Gc, along with ribonucleoprotein complexes (RNPs), composed of encapsidated genomes carrying N protein and the viral polymerase, L protein. A quantitative analysis of the profile of viral RNA segments packaged into RVFV particles showed that all three genomic RNA segments had similar packaging abilities, whereas among antigenomic RNA segments, the antigenomic S RNA, which serves as the template for the transcription of mRNA expressing the RVFV virulence factor, NSs, displayed a significantly higher packaging ability. To delineate the factor(s) governing the packaging of RVFV RNA segments, we characterized the interactions between Gn and viral RNPs in RVFV-infected cells. Coimmunoprecipitation analysis demonstrated the interaction of Gn with N protein, L protein, and viral RNAs in RVFV-infected cells. Furthermore, UV-cross-linking and immunoprecipitation analysis revealed, for the first time in bunyaviruses, the presence of a direct interaction between Gn and all the viral RNA segments in RVFV-infected cells. Notably, analysis of the ability of Gn to bind to RVFV RNA segments indicated a positive correlation with their respective packaging abilities and highlighted a binding preference of Gn for antigenomic S RNA, among the antigenomic RNA segments, suggesting the presence of a selection mechanism for antigenomic S RNA incorporation into infectious RVFV particles. Collectively, the results of our study illuminate the importance of a direct interaction between Gn and viral RNA segments in determining their efficiency of incorporation into RVFV particles. IMPORTANCE Rift Valley fever phlebovirus, a bunyavirus, is a mosquito-borne, segmented RNA virus that can cause severe disease in humans and ruminants. An essential step in RVFV life cycle is the packaging of viral RNA segments to produce infectious virus particles for dissemination to new hosts. However, there are key gaps in knowledge regarding the mechanisms that regulate viral RNA packaging efficiency in bunyaviruses. Our studies investigating the mechanism of RNA packaging in RVFV revealed the presence of a direct interaction between the viral envelope glycoprotein, Gn, and the viral RNA segments in infected cells, for the first time in bunyaviruses. Furthermore, our data strongly indicate a critical role for the direct interaction between Gn and viral RNAs in determining the efficiency of incorporation of viral RNA segments into RVFV particles. Clarifying the fundamental mechanisms of RNA packaging in RVFV would be valuable for the development of antivirals and live-attenuated vaccines.
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A Look into Bunyavirales Genomes: Functions of Non-Structural (NS) Proteins. Viruses 2021; 13:v13020314. [PMID: 33670641 PMCID: PMC7922539 DOI: 10.3390/v13020314] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/12/2021] [Accepted: 02/16/2021] [Indexed: 12/13/2022] Open
Abstract
In 2016, the Bunyavirales order was established by the International Committee on Taxonomy of Viruses (ICTV) to incorporate the increasing number of related viruses across 13 viral families. While diverse, four of the families (Peribunyaviridae, Nairoviridae, Hantaviridae, and Phenuiviridae) contain known human pathogens and share a similar tri-segmented, negative-sense RNA genomic organization. In addition to the nucleoprotein and envelope glycoproteins encoded by the small and medium segments, respectively, many of the viruses in these families also encode for non-structural (NS) NSs and NSm proteins. The NSs of Phenuiviridae is the most extensively studied as a host interferon antagonist, functioning through a variety of mechanisms seen throughout the other three families. In addition, functions impacting cellular apoptosis, chromatin organization, and transcriptional activities, to name a few, are possessed by NSs across the families. Peribunyaviridae, Nairoviridae, and Phenuiviridae also encode an NSm, although less extensively studied than NSs, that has roles in antagonizing immune responses, promoting viral assembly and infectivity, and even maintenance of infection in host mosquito vectors. Overall, the similar and divergent roles of NS proteins of these human pathogenic Bunyavirales are of particular interest in understanding disease progression, viral pathogenesis, and developing strategies for interventions and treatments.
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Terasaki K, Juelich TL, Smith JK, Kalveram B, Perez DD, Freiberg AN, Makino S. A single-cycle replicable Rift Valley fever phlebovirus vaccine carrying a mutated NSs confers full protection from lethal challenge in mice. Sci Rep 2018; 8:17097. [PMID: 30459418 PMCID: PMC6244155 DOI: 10.1038/s41598-018-35472-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/05/2018] [Indexed: 11/09/2022] Open
Abstract
Rift Valley fever phlebovirus (RVFV) is a pathogen of Rift Valley fever, which is a mosquito-borne zoonotic disease for domestic livestock and humans in African countries. Currently, no approved vaccine is available for use in non-endemic areas. The MP-12 strain is so far the best live attenuated RVFV vaccine candidate because of its good protective efficacy in animal models. However, there are safety concerns for use of MP-12 in humans. We previously developed a single-cycle replicable MP-12 (scMP-12) which lacks NSs gene and undergoes only a single round of viral replication because of its impaired ability to induce membrane-membrane fusion. In the present study, we generated an scMP-12 mutant (scMP-12-mutNSs) carrying a mutant NSs, which degrades double-stranded RNA-dependent protein kinase R but does not inhibit host transcription. Immunization of mice with a single dose (105 PFU) of scMP-12-mutNSs elicited RVFV neutralizing antibodies and high titers of anti-N IgG production and fully protected the mice from lethal wild-type RVFV challenge. Immunogenicity and protective efficacy of scMP-12-mutNSs were better than scMP-12, demonstrating that scMP-12-mutNSs is a more efficacious vaccine candidate than scMP-12. Furthermore, our data suggested that RVFV vaccine efficacy can be improved by using this specific NSs mutant.
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Affiliation(s)
- Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Terry L Juelich
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Jennifer K Smith
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Birte Kalveram
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - David D Perez
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Alexander N Freiberg
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.
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Pinkham C, Ahmed A, Bracci N, Narayanan A, Kehn-Hall K. Host-based processes as therapeutic targets for Rift Valley fever virus. Antiviral Res 2018; 160:64-78. [PMID: 30316916 DOI: 10.1016/j.antiviral.2018.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 09/27/2018] [Accepted: 10/05/2018] [Indexed: 12/28/2022]
Abstract
Rift Valley fever virus (RVFV) is an enveloped, segmented, negative sense RNA virus that replicates within the host's cytoplasm. To facilitate its replication, RVFV must utilize host cell processes and as such, these processes may serve as potential therapeutic targets. This review summarizes key host cell processes impacted by RVFV infection. Specifically the influence of RVFV on host transcriptional regulation, post-transcriptional regulation, protein half-life and availability, host signal transduction, trafficking and secretory pathways, cytoskeletal modulation, and mitochondrial processes and oxidative stress are discussed. Therapeutics targeted towards host processes that are essential for RVFV to thrive as well as their efficacy and importance to viral pathogenesis are highlighted.
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Affiliation(s)
- Chelsea Pinkham
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Aslaa Ahmed
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Nicole Bracci
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Aarthi Narayanan
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Kylene Kehn-Hall
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA.
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12
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de la Fuente C, Pinkham C, Dabbagh D, Beitzel B, Garrison A, Palacios G, Hodge KA, Petricoin EF, Schmaljohn C, Campbell CE, Narayanan A, Kehn-Hall K. Phosphoproteomic analysis reveals Smad protein family activation following Rift Valley fever virus infection. PLoS One 2018; 13:e0191983. [PMID: 29408900 PMCID: PMC5800665 DOI: 10.1371/journal.pone.0191983] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 01/15/2018] [Indexed: 01/07/2023] Open
Abstract
Rift Valley fever virus (RVFV) infects both ruminants and humans leading to a wide variance of pathologies dependent on host background and age. Utilizing a targeted reverse phase protein array (RPPA) to define changes in signaling cascades after in vitro infection of human cells with virulent and attenuated RVFV strains, we observed high phosphorylation of Smad transcription factors. This evolutionarily conserved family is phosphorylated by and transduces the activation of TGF-β superfamily receptors. Moreover, we observed that phosphorylation of Smad proteins required active RVFV replication and loss of NSs impaired this activation, further corroborating the RPPA results. Gene promoter analysis of transcripts altered after RVFV infection identified 913 genes that contained a Smad-response element. Functional annotation of these potential Smad-regulated genes clustered in axonal guidance, hepatic fibrosis and cell signaling pathways involved in cellular adhesion/migration, calcium influx, and cytoskeletal reorganization. Furthermore, chromatin immunoprecipitation confirmed the presence of a Smad complex on the interleukin 1 receptor type 2 (IL1R2) promoter, which acts as a decoy receptor for IL-1 activation.
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Affiliation(s)
- Cynthia de la Fuente
- 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
| | - Deemah Dabbagh
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Brett Beitzel
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Aura Garrison
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Gustavo Palacios
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Kimberley Alex Hodge
- Center for Applied Proteomics and Molecular Medicine, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Emanuel F. Petricoin
- Center for Applied Proteomics and Molecular Medicine, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Connie Schmaljohn
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | | | - Aarthi Narayanan
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, 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
- * E-mail:
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