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Frost TC, Salnikov M, Rice SA. Enhancement of HSV-1 cell-free virion release by the envelope protein gC. Virology 2024; 596:110120. [PMID: 38805801 PMCID: PMC11178091 DOI: 10.1016/j.virol.2024.110120] [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: 03/22/2024] [Revised: 05/08/2024] [Accepted: 05/21/2024] [Indexed: 05/30/2024]
Abstract
Glycoprotein C (gC), one of ∼12 HSV-1 envelope glycoproteins, carries out several important functions during infection, including the enhancement of virion attachment by binding to host cell heparan sulfate proteoglycans (HSPG). Here we report that gC can also enhance the release of cell-free progeny virions at the end of the infectious cycle. This activity was observed in multiple cellular contexts including Vero cells and immortalized human keratinocytes. In the absence of gC, progeny virions bound more tightly to infected cells, suggesting that gC promotes the detachment of virions from the infected cell surface. Given this finding, we analyzed the biochemical interactions that tether progeny virions to cells and report evidence for two distinct modes of binding. One is consistent with a direct interaction between gC and HSPG, whereas the other is gC-independent and likely does not involve HSPG. Together, our results i) identify a novel function for a long-studied HSV-1 glycoprotein, and ii) demonstrate that the extracellular release of HSV-1 virions is a dynamic process involving multiple viral and host components.
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Affiliation(s)
- Thomas C Frost
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Mark Salnikov
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Stephen A Rice
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
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2
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Kinoshita H, Yamada S, Ogawa T, Nguyen PHA, Harada S, Kawahara M, Ishijima K, Maeda K, Ebihara H, Fukushi S. Development of a vesicular stomatitis virus pseudotyped with herpes B virus glycoproteins and its application in a neutralizing antibody detection assay. mBio 2024; 15:e0109224. [PMID: 38847539 PMCID: PMC11253632 DOI: 10.1128/mbio.01092-24] [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: 04/11/2024] [Accepted: 05/02/2024] [Indexed: 07/18/2024] Open
Abstract
Herpes B virus (BV) is a zoonotic virus and belongs to the genus Simplexvius, the same genus as human herpes simplex virus (HSV). BV typically establishes asymptomatic infection in its natural hosts, macaque monkeys. However, in humans, BV infection causes serious neurological diseases and death. As such, BV research can only be conducted in a high containment level facility (i.e., biosafety level [BSL] 4), and the mechanisms of BV entry have not been fully elucidated. In this study, we generated a pseudotyped vesicular stomatitis virus (VSV) expressing BV glycoproteins using G-complemented VSV∆G system, which we named VSV/BVpv. We found that four BV glycoproteins (i.e., gB, gD, gH, and gL) were required for the production of a high-titer VSV/BVpv. Moreover, VSV/BVpv cell entry was dependent on the binding of gD to its cellular receptor nectin-1. Pretreatment of Vero cells with endosomal acidification inhibitors did not affect the VSV/BVpv infection. The result indicated that VSV/BVpv entry occurred by direct fusion with the plasma membrane of Vero cells and suggested that the entry pathway was similar to that of native HSV. Furthermore, we developed a VSV/BVpv-based chemiluminescence reduction neutralization test (CRNT), which detected the neutralization antibodies against BV in macaque plasma samples with high sensitivity and specificity. Crucially, the VSV/BVpv generated in this study can be used under BSL-2 condition to study the initial entry process through gD-nectin-1 interaction and the direct fusion of BV with the plasma membrane of Vero cells.IMPORTANCEHerpes B virus (BV) is a highly pathogenic zoonotic virus against humans. BV belongs to the genus Simplexvius, the same genus as human herpes simplex virus (HSV). By contrast to HSV, cell entry mechanisms of BV are not fully understood. The research procedures to manipulate infectious BV should be conducted in biosafety level (BSL)-4 facilities. As pseudotyped viruses provide a safe viral entry model because of their inability to produce infectious progeny virus, we tried to generate a pseudotyped vesicular stomatitis virus bearing BV glycoproteins (VSV/BVpv) by modification of expression constructs of BV glycoproteins, and successfully obtained VSV/BVpv with a high titer. This study has provided novel information for constructing VSV/BVpv and its usefulness to study BV infection.
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Affiliation(s)
- Hitomi Kinoshita
- Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan
| | - Souichi Yamada
- Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takuma Ogawa
- Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan
| | - Phu Hoang Anh Nguyen
- Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan
| | - Shizuko Harada
- Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan
| | - Madoka Kawahara
- Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan
| | - Keita Ishijima
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan
| | - Ken Maeda
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hideki Ebihara
- Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan
| | - Shuetsu Fukushi
- Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan
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Gianopulos KA, Makio AO, Pritchard SM, Cunha CW, Hull MA, Nicola AV. Herpes Simplex Virus 1 Glycoprotein B from a Hyperfusogenic Virus Mediates Enhanced Cell-Cell Fusion. Viruses 2024; 16:251. [PMID: 38400027 PMCID: PMC10892784 DOI: 10.3390/v16020251] [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: 12/05/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Herpes simplex virus 1 (HSV-1) causes significant morbidity and death in humans worldwide. Herpes simplex virus 1 has a complex fusion mechanism that is incompletely understood. The HSV-1 strain ANG has notable fusion and entry activities that distinguish it from wild type. HSV-1 ANG virions fused with the Vero cell surface at 4 °C and also entered cells more efficiently at 15 °C, relative to wild type HSV-1 strain KOS virions, consistent with a hyperfusogenic phenotype. Understanding the molecular basis for the unique entry and fusion activities of HSV-1 strain ANG will help decipher the HSV fusion reaction and entry process. Sequencing of HSV-1 ANG genes revealed multiple changes in gB, gC, gD, gH, and gL proteins relative to wild type HSV-1 strains. The ANG UL45 gene sequence, which codes for a non-essential envelope protein, was identical to wild type KOS. HSV-1 ANG gB, gD, and gH/gL were necessary and sufficient to mediate cell-cell fusion in a virus-free reporter assay. ANG gB, when expressed with wild type KOS gD and gH/gL, increased membrane fusion, suggesting that ANG gB has hyperfusogenic cell-cell fusion activity. Replacing the KOS gD, gH, or gL with the corresponding ANG alleles did not enhance cell-cell fusion. The novel mutations in the ANG fusion and entry glycoproteins provide a platform for dissecting the cascade of interactions that culminate in HSV fusion and entry.
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Affiliation(s)
- Katrina A. Gianopulos
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA; (K.A.G.); (A.O.M.); (C.W.C.)
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
- Protein Biotechnology Graduate Training Program, Washington State University, Pullman, WA 99164, USA
| | - Albina O. Makio
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA; (K.A.G.); (A.O.M.); (C.W.C.)
- Protein Biotechnology Graduate Training Program, Washington State University, Pullman, WA 99164, USA
| | - Suzanne M. Pritchard
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA; (K.A.G.); (A.O.M.); (C.W.C.)
| | - Cristina W. Cunha
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA; (K.A.G.); (A.O.M.); (C.W.C.)
- Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture, Pullman, WA 99164, USA
| | - McKenna A. Hull
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA; (K.A.G.); (A.O.M.); (C.W.C.)
| | - Anthony V. Nicola
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA; (K.A.G.); (A.O.M.); (C.W.C.)
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Zhong X, Zhang Y, Yuan M, Xu L, Luo X, Wu R, Xi Z, Li Y, Xu H. Prunella vulgaris polysaccharide inhibits herpes simplex virus infection by blocking TLR-mediated NF-κB activation. Chin Med 2024; 19:6. [PMID: 38185640 PMCID: PMC10773030 DOI: 10.1186/s13020-023-00865-y] [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: 07/21/2023] [Accepted: 11/22/2023] [Indexed: 01/09/2024] Open
Abstract
BACKGROUND Prunella vulgaris polysaccharide extracted by hot water and 30% ethanol precipitation (PVE30) was reported to possess potent antiviral effects against herpes simplex virus (HSV) infection. However, its anti-HSV mechanism has not yet been fully elucidated. PURPOSE This study aimed to investigate the potential mechanisms of PVE30 against HSV infection. METHODS Antiviral activity was evaluated by a plaque reduction assay, and the EC50 value was calculated. Immunofluorescence staining and heparin bead pull-down assays confirmed the interactions between PVE30 and viral glycoproteins. Real-time PCR was conducted to determine the mRNA levels of viral genes, including UL54, UL29, UL27, UL44, and US6, and the proinflammatory cytokines IL-6 and TNF-α. The protein expression of viral proteins (ICP27, ICP8, gB, gC, and gD), the activity of the TLR-NF-κB signalling pathway, and necroptotic-associated proteins were evaluated by Western blotting. The proportion of necroptotic cells was determined by flow cytometric analysis. RESULTS The P. vulgaris polysaccharide PVE30 was shown to compete with heparan sulfate for interaction with HSV surface glycoprotein B and gC, thus strongly inhibiting HSV attachment to cells. In addition, PVE30 downregulated the expression of IE genes, which subsequently downregulated the expression of E and L viral gene products, and thus effectively restricted the yield of progeny virus. Further investigation confirmed that PVE30 inhibited TLR2 and TLR3 signalling, leading to the effective suppression of NF-κB activation and IL-6 and TNF-α expression levels, and blocked HSV-1-induced necroptosis by reducing HSV-1-induced phosphorylation of MLKL. CONCLUSION Our results demonstrate that the P. vulgaris polysaccharide PVE30 is a potent anti-HSV agent that blocks TLR-mediated NF-κB activation.
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Affiliation(s)
- Xuanlei Zhong
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, No. 1200, Cailun Road, Shanghai, 201203, China
- Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China
| | - Yibo Zhang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, No. 1200, Cailun Road, Shanghai, 201203, China
- Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China
| | - Man Yuan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, No. 1200, Cailun Road, Shanghai, 201203, China
- Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China
| | - Lin Xu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, No. 1200, Cailun Road, Shanghai, 201203, China
- Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China
| | - Xiaomei Luo
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, No. 1200, Cailun Road, Shanghai, 201203, China
- Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China
| | - Rong Wu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, No. 1200, Cailun Road, Shanghai, 201203, China
- Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China
| | - Zhichao Xi
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, No. 1200, Cailun Road, Shanghai, 201203, China
- Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China
| | - Yang Li
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, No. 1200, Cailun Road, Shanghai, 201203, China.
- Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China.
| | - Hongxi Xu
- Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
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5
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Gianopulos KA, Makio AO, Pritchard SM, Cunha CW, Hull MA, Nicola AV. Membrane fusion activity of herpes simplex virus 1 glycoproteins from a hyperfusogenic virus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.04.569993. [PMID: 38106075 PMCID: PMC10723375 DOI: 10.1101/2023.12.04.569993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Herpes simplex virus 1 (HSV-1) causes significant morbidity and death in humans worldwide. Herpes simplex virus 1 has a complex fusion mechanism that is incompletely understood. The HSV-1 strain ANG has notable fusion and entry activities that distinguish it from wild type. HSV-1 ANG virions fused with the Vero cell surface at 4°C and also entered cells more efficiently at 15°C relative to wild type virions, consistent with a hyperfusogenic phenotype. Understanding the molecular basis for the unique entry and fusion activities of HSV-1 strain ANG will help decipher the HSV fusion reaction and entry process. Sequencing of HSV-1 ANG genes revealed multiple changes in gB, gC, gD, gH, and gL proteins relative to wild type HSV-1 strains. The ANG UL45 gene sequence, which codes for a non-essential envelope protein, was identical to wild type. HSV-1 ANG gB, gD, and gH/gL were necessary and sufficient to mediate cell-cell fusion in a virus-free reporter assay. ANG gB, when expressed with wild type gD and gH/gL, increased membrane fusion, suggesting that ANG gB has hyperfusogenic cell-cell fusion activity. Replacing the wild type gD, gH, or gL with the corresponding ANG alleles did not enhance cell-cell fusion. Wild type gC is proposed to facilitate fusion and entry into epithelial cells by optimizing conformational changes in the fusion protein gB. ANG gC substitution or addition also had no effect on cell-cell fusion. The novel mutations in the ANG fusion and entry glycoproteins provide a platform for dissecting the cascade of interactions that culminate in HSV fusion and entry.
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6
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Sasivimolrattana T, Bhattarakosol P. Impact of actin polymerization and filopodia formation on herpes simplex virus entry in epithelial, neuronal, and T lymphocyte cells. Front Cell Infect Microbiol 2023; 13:1301859. [PMID: 38076455 PMCID: PMC10704452 DOI: 10.3389/fcimb.2023.1301859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 11/07/2023] [Indexed: 12/18/2023] Open
Abstract
Herpes simplex virus type 1 (HSV-1) has been known as a common viral pathogen that can infect several parts of the body, leading to various clinical manifestations. According to this diverse manifestation, HSV-1 infection in many cell types was demonstrated. Besides the HSV-1 cell tropism, e.g., fibroblast, epithelial, mucosal cells, and neurons, HSV-1 infections can occur in human T lymphocyte cells, especially in activated T cells. In addition, several studies found that actin polymerization and filopodia formation support HSV-1 infection in diverse cell types. Hence, the goal of this review is to explore the mechanism of HSV-1 infection in various types of cells involving filopodia formation and highlight potential future directions for HSV-1 entry-related research. Moreover, this review covers several strategies for possible anti-HSV drugs focused on the entry step, offering insights into potential therapeutic interventions.
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Affiliation(s)
| | - Parvapan Bhattarakosol
- Center of Excellence in Applied Medical Virology, Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Division of Virology, Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
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7
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Zhang C, Chen H, Sun L, Zhao P, Qi C, Yang Y, Si A, Qian Y, Jung YS. Bis-Benzylisoquinoline Alkaloids Inhibit Porcine Epidemic Diarrhea Virus by Disrupting Virus Entry. Pathogens 2023; 12:845. [PMID: 37375535 DOI: 10.3390/pathogens12060845] [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: 04/20/2023] [Revised: 06/13/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
The porcine epidemic diarrhea virus (PEDV), belonging to the α-coronavirus, is the causative agent of porcine epidemic diarrhea (PED). Presently, protection from the existing PEDV vaccine is not effective. Therefore, anti-PEDV compounds should be studied. Berbamine (BBM), Fangchinoline (FAN), and (+)-Fangchinoline (+FAN), are types of bis-benzylisoquinoline alkaloids that are extracted from natural medicinal plants. These bis-benzylisoquinoline alkaloids have various biological activities, including antiviral, anticancer, and anti-inflammatory properties. In this study, we found that BBM, FAN, and +FAN suppressed PEDV activity with a 50% inhibitory concentration of 9.00 µM, 3.54 µM, and 4.68 µM, respectively. Furthermore, these alkaloids can decrease the PEDV-N protein levels and virus titers in vitro. The time-of-addition assay results showed that these alkaloids mainly inhibit PEDV entry. We also found that the inhibitory effects of BBM, FAN, and +FAN on PEDV rely on decreasing the activity of Cathepsin L (CTSL) and Cathepsin B (CTSB) by suppressing lysosome acidification. Taken together, these results indicated that BBM, FAN, and +FAN were effective anti-PEDV natural products that prevented PEDV entry and may be considered novel antiviral drugs.
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Affiliation(s)
- Caisheng Zhang
- One Health Laboratory, Jiangsu Foreign Expert Workshop, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Huan Chen
- One Health Laboratory, Jiangsu Foreign Expert Workshop, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Liumei Sun
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Pu Zhao
- One Health Laboratory, Jiangsu Foreign Expert Workshop, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Chuanxiang Qi
- One Health Laboratory, Jiangsu Foreign Expert Workshop, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Ying Yang
- One Health Laboratory, Jiangsu Foreign Expert Workshop, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Anqi Si
- One Health Laboratory, Jiangsu Foreign Expert Workshop, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Yingjuan Qian
- One Health Laboratory, Jiangsu Foreign Expert Workshop, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for High-Tech Research and Development of Veterinary Biopharmaceuticals, Jiangsu Agri-Animal Husbandry Vocational College, Veterinary Bio-Pharmaceutical, Taizhou 225300, China
| | - Yong-Sam Jung
- One Health Laboratory, Jiangsu Foreign Expert Workshop, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
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Wu Y, Tan S, He Q, Wang M, Chen S, Jia R, Yang Q, Zhu D, Liu M, Zhao X, Zhang S, Huang J, Ou X, Mao S, Gao Q, Sun D, Tian B, Cheng A. Deletion of Double Copies of the US1 Gene Reduces the Infectivity of Recombinant Duck Plague Virus In Vitro and In Vivo. Microbiol Spectr 2022; 10:e0114022. [PMID: 36377937 PMCID: PMC9784771 DOI: 10.1128/spectrum.01140-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022] Open
Abstract
Duck plague caused by duck plague virus (DPV) is one of the main diseases that seriously endangers the production of waterfowl. DPV possesses a large genome consisting of 78 open reading frames (ORFs), and understanding the function and mechanism of each encoded protein in viral replication and pathogenesis is the key to controlling duck plague outbreaks. US1 is one of the two genes located in the repeat regions of the DPV genome, but the function of its encoded protein in DPV replication and pathogenesis remains unclear. Previous studies found that the US1 gene or its homologs exist in almost all alphaherpesviruses, but the loci, functions, and pathogenesis of their encoded proteins vary among different viruses. Here, we aimed to define the roles of US1 genes in DPV infection and pathogenesis by generating a double US1 gene deletion mutant and its revertant without any mini-F cassette retention. In vitro and in vivo studies found that deletion of both copies of the US1 gene significantly impaired the replication, gene expression, and virulence of DPV, which could represent a potential candidate vaccine strain for the prevention of duck plague. IMPORTANCE Duck plague virus contains nearly 80 genes, but the functions and mechanisms of most of the genes have not yet been elucidated, including those of the newly identified immediate early gene US1. Here, we found that US1 deletion reduces viral gene expression, replication, and virus production both in vitro and in vivo. This insight defines a fundamental role of the US1 gene in DPV infection and indicates its involvement in DPV transcription. These results provide clues for the study of the pathogenesis of the US1 gene and the development of attenuated vaccines targeting this gene.
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Affiliation(s)
- Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Silun Tan
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Qing He
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Dekang Zhu
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Xinxin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Juan Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Xumin Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Sai Mao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Di Sun
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Bin Tian
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Wenjiang, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, China
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Lee BH, Tebaldi G, Pritchard SM, Nicola AV. Host Cell Neddylation Facilitates Alphaherpesvirus Entry in a Virus-Specific and Cell-Dependent Manner. Microbiol Spectr 2022; 10:e0311422. [PMID: 36173301 PMCID: PMC9603186 DOI: 10.1128/spectrum.03114-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 09/13/2022] [Indexed: 01/04/2023] Open
Abstract
Herpes simplex virus 1 (HSV-1) commandeers the host cell proteasome at several steps of its replication cycle, including entry. Here we demonstrate that HSV-2, pseudorabies virus (PRV), and bovine herpesvirus 1 (BoHV-1) entry are blocked by bortezomib, a proteasome inhibitor that is an FDA-approved cancer drug. Proteasome-dependent entry of HSV-1 is thought to be ubiquitin-independent. To interrogate further the proteasomal mechanism of entry, we determined the involvement of the ubiquitin-like molecule NEDD8 and the neddylation cascade in alphaherpesvirus entry and infection. MLN4924 is a small-molecule inhibitor of neddylation that binds directly to the NEDD8-activating enzyme. Cell treatment with MLN4924 inhibited plaque formation and infectivity by HSV-1, PRV, and BoHV-1 at noncytotoxic concentrations. Thus, the neddylation pathway is broadly important for alphaherpesvirus infection. However, the neddylation inhibitor had little effect on entry of the veterinary viruses but had a significant inhibitory effect on entry of HSV-1 and HSV-2 into seven different cell types. Washout experiments indicated that MLN4924's effect on viral entry was reversible. A time-of-addition assay suggested that the drug was acting on an early step in the entry process. Small interfering RNA (siRNA) knockdown of NEDD8 significantly inhibited HSV entry. In probing the neddylation-dependent step in entry, we found that MLN4924 dramatically blocked endocytic uptake of HSV from the plasma membrane by >90%. In contrast, the rate of HSV entry into cells that support direct fusion of HSV with the cell surface was unaffected by MLN4924. Interestingly, proteasome activity was less important for the endocytic internalization of HSV from the cell surface. The results suggest that the NEDD8 cascade is critical for the internalization step of HSV entry. IMPORTANCE Alphaherpesviruses are ubiquitous pathogens of humans and veterinary species that cause lifelong latent infections and significant morbidity and mortality. Host cell neddylation is important for cell homeostasis and for the infection of many viruses, including HSV-1, HSV-2, PRV, and BoHV-1. Inhibition of neddylation by a pharmacologic inhibitor or siRNA blocked HSV infection at the entry step. Specifically, the NEDD8 pathway was critically important for HSV-1 internalization from the cell surface by an endocytosis mechanism. The results expand our limited understanding of cellular processes that mediate HSV internalization. To our knowledge, this is the first demonstration of a function for the neddylation cascade in virus entry.
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Affiliation(s)
- Becky H. Lee
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Giulia Tebaldi
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Suzanne M. Pritchard
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Anthony V. Nicola
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
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10
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Gianopulos KA, Komala Sari T, Weed DJ, Pritchard SM, Nicola AV. Conformational Changes in Herpes Simplex Virus Glycoprotein C. J Virol 2022; 96:e0016322. [PMID: 35913218 PMCID: PMC9400475 DOI: 10.1128/jvi.00163-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 07/05/2022] [Indexed: 02/03/2023] Open
Abstract
Low endosomal pH facilitates herpesvirus entry in a cell-specific manner. Herpes simplex virus 1 (HSV-1) causes significant morbidity and death in humans worldwide. HSV-1 enters cells by low-pH and neutral-pH pathways. Low-pH-induced conformational changes in the HSV envelope glycoprotein B (gB) may mediate membrane fusion during viral entry. HSV-1 gC, a 511-amino acid, type I integral membrane glycoprotein, mediates HSV-1 attachment to host cell surface glycosaminoglycans, but this interaction is not essential for viral entry. We previously demonstrated that gC regulates low-pH viral entry independent of its known role in cell attachment. Low-pH-triggered conformational changes in gB occur at a lower pH when gC is absent, suggesting that gC positively regulates gB conformational changes. Here, we demonstrate that mildly acidic pH triggers conformational changes in gC itself. Low-pH treatment of virions induced antigenic changes in distinct gC epitopes, and those changes were reversible. One of these gC epitopes is recognized by a monoclonal antibody that binds to a linear sequence that includes residues within gC amino acids 33 to 123. This antibody inhibited low-pH entry of HSV, suggesting that its gC N-terminal epitope is particularly important. We propose that gC plays a critical role in HSV entry through a low-pH endocytosis pathway, which is a major entry route in human epithelial cells. IMPORTANCE Herpesviruses are ubiquitous pathogens that cause lifelong latent infections and are characterized by multiple entry pathways. The HSV envelope gC regulates HSV entry by a low-pH entry route. The fusion protein gB undergoes pH-triggered conformational changes that are facilitated by gC. Here, we report that gC itself undergoes a conformational change at low pH. A monoclonal antibody to gC that binds to a region that undergoes pH-induced changes also selectively inhibits HSV low-pH entry, corroborating the importance of gC in the low-pH entry pathway. This study illustrates the complex role of endosomal pH during HSV entry and provides novel insights into the functions of gC.
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Affiliation(s)
- Katrina A. Gianopulos
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
- Protein Biotechnology Graduate Training Program, Washington State University, Pullman, Washington, USA
| | - Tri Komala Sari
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
- Protein Biotechnology Graduate Training Program, Washington State University, Pullman, Washington, USA
- Faculty of Veterinary Medicine, Udayana University, Bali, Indonesia
| | - Darin J. Weed
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
- Protein Biotechnology Graduate Training Program, Washington State University, Pullman, Washington, USA
| | - Suzanne M. Pritchard
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Anthony V. Nicola
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
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11
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Mazzara PG, Criscuolo E, Rasponi M, Massimino L, Muggeo S, Palma C, Castelli M, Clementi M, Burioni R, Mancini N, Broccoli V, Clementi N. A Human Stem Cell-Derived Neurosensory–Epithelial Circuitry on a Chip to Model Herpes Simplex Virus Reactivation. Biomedicines 2022; 10:biomedicines10092068. [PMID: 36140168 PMCID: PMC9495731 DOI: 10.3390/biomedicines10092068] [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: 08/09/2022] [Accepted: 08/20/2022] [Indexed: 11/16/2022] Open
Abstract
Both emerging viruses and well-known viral pathogens endowed with neurotropism can either directly impair neuronal functions or induce physio-pathological changes by diffusing from the periphery through neurosensory–epithelial connections. However, developing a reliable and reproducible in vitro system modeling the connectivity between the different human sensory neurons and peripheral tissues is still a challenge and precludes the deepest comprehension of viral latency and reactivation at the cellular and molecular levels. This study shows a stable topographic neurosensory–epithelial connection on a chip using human stem cell-derived dorsal root ganglia (DRG) organoids. Bulk and single-cell transcriptomics showed that different combinations of key receptors for herpes simplex virus 1 (HSV-1) are expressed by each sensory neuronal cell type. This neuronal–epithelial circuitry enabled a detailed analysis of HSV infectivity, faithfully modeling its dynamics and cell type specificity. The reconstitution of an organized connectivity between human sensory neurons and keratinocytes into microfluidic chips provides a powerful in vitro platform for modeling viral latency and reactivation of human viral pathogens.
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Affiliation(s)
| | - Elena Criscuolo
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Marco Rasponi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, 20133 Milan, Italy
| | - Luca Massimino
- Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Sharon Muggeo
- Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Cecilia Palma
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, 20133 Milan, Italy
| | - Matteo Castelli
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Massimo Clementi
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, 20132 Milan, Italy
- Laboratory of Microbiology and Virology, IRCCS San Raffaele Hospital, 20132 Milan, Italy
| | - Roberto Burioni
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Nicasio Mancini
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, 20132 Milan, Italy
- Laboratory of Microbiology and Virology, IRCCS San Raffaele Hospital, 20132 Milan, Italy
| | - Vania Broccoli
- Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
- National Research Council (CNR), Institute of Neuroscience, 20129 Milan, Italy
- Correspondence: (V.B.); (N.C.); Tel.: +39-022-643-4616 (V.B.); +39-022-643-3144 (N.C.)
| | - Nicola Clementi
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, 20132 Milan, Italy
- Laboratory of Microbiology and Virology, IRCCS San Raffaele Hospital, 20132 Milan, Italy
- Correspondence: (V.B.); (N.C.); Tel.: +39-022-643-4616 (V.B.); +39-022-643-3144 (N.C.)
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12
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Ebel H, Benecke T, Vollmer B. Stabilisation of Viral Membrane Fusion Proteins in Prefusion Conformation by Structure-Based Design for Structure Determination and Vaccine Development. Viruses 2022; 14:1816. [PMID: 36016438 PMCID: PMC9415420 DOI: 10.3390/v14081816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 08/08/2022] [Accepted: 08/15/2022] [Indexed: 11/20/2022] Open
Abstract
The membrane surface of enveloped viruses contains dedicated proteins enabling the fusion of the viral with the host cell membrane. Working with these proteins is almost always challenging because they are membrane-embedded and naturally metastable. Fortunately, based on a range of different examples, researchers now have several possibilities to tame membrane fusion proteins, making them amenable for structure determination and immunogen generation. This review describes the structural and functional similarities of the different membrane fusion proteins and ways to exploit these features to stabilise them by targeted mutational approaches. The recent determination of two herpesvirus membrane fusion proteins in prefusion conformation holds the potential to apply similar methods to this group of viral fusogens. In addition to a better understanding of the herpesviral fusion mechanism, the structural insights gained will help to find ways to further stabilise these proteins using the methods described to obtain stable immunogens that will form the basis for the development of the next generation of vaccines and antiviral drugs.
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Affiliation(s)
- Henriette Ebel
- Centre for Structural Systems Biology (CSSB), 22607 Hamburg, Germany
- Department of Chemistry, University of Hamburg, 20146 Hamburg, Germany
- Leibniz Institute of Virology (LIV), 20251 Hamburg, Germany
| | - Tim Benecke
- Centre for Structural Systems Biology (CSSB), 22607 Hamburg, Germany
- Department of Chemistry, University of Hamburg, 20146 Hamburg, Germany
- Leibniz Institute of Virology (LIV), 20251 Hamburg, Germany
| | - Benjamin Vollmer
- Centre for Structural Systems Biology (CSSB), 22607 Hamburg, Germany
- Department of Chemistry, University of Hamburg, 20146 Hamburg, Germany
- Leibniz Institute of Virology (LIV), 20251 Hamburg, Germany
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13
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Interplay between H1N1 influenza a virus infection, extracellular and intracellular respiratory tract pH, and host responses in a mouse model. PLoS One 2021; 16:e0251473. [PMID: 33979408 PMCID: PMC8115840 DOI: 10.1371/journal.pone.0251473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 04/27/2021] [Indexed: 01/01/2023] Open
Abstract
During influenza A virus (IAV) entry, the hemagglutinin (HA) protein is triggered by endosomal low pH to undergo irreversible structural changes that mediate membrane fusion. HA proteins from different isolates vary in the pH at which they become activated in endosomes or become irreversible inactivated if exposed to extracellular acid. Little is known about extracellular pH in the upper respiratory tracts of mammals, how pH may shift during IAV infection, and its impact on replication of viruses that vary in HA activation pH. Here, we inoculated DBA/2J mice intranasally with A/TN/1-560/2009 (H1N1) (activation pH 5.5) or a mutant containing the destabilizing mutation HA1-Y17H (pH 6.0). We measured the kinetics of extracellular pH during infection using an optical pH-sensitive microsensor probe placed in the naris, nasal sinus, soft palate, and trachea. We also measured intracellular pH of single-cell suspensions of live, primary lung epithelial cells with various wavelength pH-sensitive dyes localized to cell membranes, cytosol, endosomes, secretory vesicles, microtubules, and lysosomes. Infection with either virus decreased extracellular pH and increased intracellular pH. Peak host immune responses were observed at 2 days post infection (DPI) and peak pH changes at 5 DPI. Extracellular and intracellular pH returned to baseline by 7 DPI in mice infected with HA1-Y17H and was restored later in wildtype-infected. Overall, IAV infection altered respiratory tract pH, which in turn modulated replication efficiency. This suggests a virus-host pH feedback loop that may select for IAV strains containing HA proteins of optimal pH stability, which may be approximately pH 5.5 in mice but may differ in other species.
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14
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Tognarelli EI, Reyes A, Corrales N, Carreño LJ, Bueno SM, Kalergis AM, González PA. Modulation of Endosome Function, Vesicle Trafficking and Autophagy by Human Herpesviruses. Cells 2021; 10:cells10030542. [PMID: 33806291 PMCID: PMC7999576 DOI: 10.3390/cells10030542] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 12/27/2022] Open
Abstract
Human herpesviruses are a ubiquitous family of viruses that infect individuals of all ages and are present at a high prevalence worldwide. Herpesviruses are responsible for a broad spectrum of diseases, ranging from skin and mucosal lesions to blindness and life-threatening encephalitis, and some of them, such as Kaposi’s sarcoma-associated herpesvirus (KSHV) and Epstein–Barr virus (EBV), are known to be oncogenic. Furthermore, recent studies suggest that some herpesviruses may be associated with developing neurodegenerative diseases. These viruses can establish lifelong infections in the host and remain in a latent state with periodic reactivations. To achieve infection and yield new infectious viral particles, these viruses require and interact with molecular host determinants for supporting their replication and spread. Important sets of cellular factors involved in the lifecycle of herpesviruses are those participating in intracellular membrane trafficking pathways, as well as autophagic-based organelle recycling processes. These cellular processes are required by these viruses for cell entry and exit steps. Here, we review and discuss recent findings related to how herpesviruses exploit vesicular trafficking and autophagy components by using both host and viral gene products to promote the import and export of infectious viral particles from and to the extracellular environment. Understanding how herpesviruses modulate autophagy, endolysosomal and secretory pathways, as well as other prominent trafficking vesicles within the cell, could enable the engineering of novel antiviral therapies to treat these viruses and counteract their negative health effects.
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Affiliation(s)
- Eduardo I. Tognarelli
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Antonia Reyes
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Nicolás Corrales
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Leandro J. Carreño
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Programa de Inmunología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Susan M. Bueno
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Alexis M. Kalergis
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Endocrinología, Facultad de Medicina, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8320000, Chile
| | - Pablo A. González
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
- Correspondence:
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15
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Hilterbrand AT, Daly RE, Heldwein EE. Contributions of the Four Essential Entry Glycoproteins to HSV-1 Tropism and the Selection of Entry Routes. mBio 2021; 12:e00143-21. [PMID: 33653890 PMCID: PMC8092210 DOI: 10.1128/mbio.00143-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 01/22/2021] [Indexed: 01/02/2023] Open
Abstract
Herpes simplex viruses (HSV-1 and HSV-2) encode up to 16 envelope proteins, four of which are essential for entry. However, whether these four proteins alone are sufficient to dictate the broad cellular tropism of HSV-1 and the selection of different cell type-dependent entry routes is unknown. To begin addressing this, we previously pseudotyped vesicular stomatitis virus (VSV), lacking its native glycoprotein G, with only the four essential entry glycoproteins of HSV-1: gB, gH, gL, and gD. This novel VSVΔG-BHLD pseudotype recapitulated several important features of HSV-1 entry: the requirement for gB, gH, gL, gD, and a cellular receptor and sensitivity to anti-gB and anti-gH/gL neutralizing antibodies. However, due to the use of a single cell type in that study, the tropism of the VSVΔG-BHLD pseudotype was not investigated. Here, we show that the cellular tropism of the pseudotype is severely limited compared to that of wild-type HSV-1 and that its entry pathways differ from the native HSV-1 entry pathways. To test the hypothesis that other HSV-1 envelope proteins may contribute to HSV-1 tropism, we generated a derivative pseudotype containing the HSV-1 glycoprotein C (VSVΔG-BHLD-gC) and observed a gC-dependent increase in entry efficiency in two cell types. We propose that the pseudotyping platform developed here has the potential to uncover functional contributions of HSV-1 envelope proteins to entry in a gain-of-function manner.IMPORTANCE Herpes simplex viruses (HSV-1 and HSV-2) contain up to 16 different proteins in their envelopes. Four of these, glycoproteins gB, gD, gH, and gL, are termed essential with regard to entry, whereas the rest are typically referred to as nonessential based on the entry phenotypes of the respective single genetic deletions. However, the single-gene deletion approach, which relies on robust loss-of-function phenotypes, may be confounded by functional redundancies among the many HSV-1 envelope proteins. We have developed a pseudotyping platform in which the essential four entry glycoproteins are isolated from the rest, which can be added back individually for systematic gain-of-function entry experiments. Here, we show the utility of this platform for dissecting the contributions of HSV envelope proteins, both the essential four and the remaining dozen (using gC as an example), to HSV entry.
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Affiliation(s)
- Adam T Hilterbrand
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Raecliffe E Daly
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Graduate Program in Cellular, Molecular, and Developmental Biology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Ekaterina E Heldwein
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Graduate Program in Cellular, Molecular, and Developmental Biology, Tufts University School of Medicine, Boston, Massachusetts, USA
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16
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"Non-Essential" Proteins of HSV-1 with Essential Roles In Vivo: A Comprehensive Review. Viruses 2020; 13:v13010017. [PMID: 33374862 PMCID: PMC7824580 DOI: 10.3390/v13010017] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 12/19/2022] Open
Abstract
Viruses encode for structural proteins that participate in virion formation and include capsid and envelope proteins. In addition, viruses encode for an array of non-structural accessory proteins important for replication, spread, and immune evasion in the host and are often linked to virus pathogenesis. Most virus accessory proteins are non-essential for growth in cell culture because of the simplicity of the infection barriers or because they have roles only during a state of the infection that does not exist in cell cultures (i.e., tissue-specific functions), or finally because host factors in cell culture can complement their absence. For these reasons, the study of most nonessential viral factors is more complex and requires development of suitable cell culture systems and in vivo models. Approximately half of the proteins encoded by the herpes simplex virus 1 (HSV-1) genome have been classified as non-essential. These proteins have essential roles in vivo in counteracting antiviral responses, facilitating the spread of the virus from the sites of initial infection to the peripheral nervous system, where it establishes lifelong reservoirs, virus pathogenesis, and other regulatory roles during infection. Understanding the functions of the non-essential proteins of herpesviruses is important to understand mechanisms of viral pathogenesis but also to harness properties of these viruses for therapeutic purposes. Here, we have provided a comprehensive summary of the functions of HSV-1 non-essential proteins.
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