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Wang P, Jin L, Zhang M, Wu Y, Duan Z, Guo Y, Wang C, Guo Y, Chen W, Liao Z, Wang Y, Lai R, Lee LP, Qin J. Blood-brain barrier injury and neuroinflammation induced by SARS-CoV-2 in a lung-brain microphysiological system. Nat Biomed Eng 2024; 8:1053-1068. [PMID: 37349391 DOI: 10.1038/s41551-023-01054-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 05/11/2023] [Indexed: 06/24/2023]
Abstract
In some patients, COVID-19 can trigger neurological symptoms with unclear pathogenesis. Here we describe a microphysiological system integrating alveolus and blood-brain barrier (BBB) tissue chips that recapitulates neuropathogenesis associated with infection by SARS-CoV-2. Direct exposure of the BBB chip to SARS-CoV-2 caused mild changes to the BBB, and infusion of medium from the infected alveolus chip led to more severe injuries on the BBB chip, including endothelial dysfunction, pericyte detachment and neuroinflammation. Transcriptomic analyses indicated downregulated expression of the actin cytoskeleton in brain endothelium and upregulated expression of inflammatory genes in glial cells. We also observed early cerebral microvascular damage following lung infection with a low viral load in the brains of transgenic mice expressing human angiotensin-converting enzyme 2. Our findings suggest that systemic inflammation is probably contributing to neuropathogenesis following SARS-CoV-2 infection, and that direct viral neural invasion might not be a prerequisite for this neuropathogenesis. Lung-brain microphysiological systems should aid the further understanding of the systemic effects and neurological complications of viral infection.
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Affiliation(s)
- Peng Wang
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
- University of Science and Technology of China, Hefei, China
- Suzhou Institute for Advanced Research, University of Science and Technology of China, Suzhou, China
| | - Lin Jin
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences-Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Min Zhang
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yunsong Wu
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zilei Duan
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences-Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yaqiong Guo
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Chaoming Wang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences-Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yingqi Guo
- Core Technology Facility of Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Wenwen Chen
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Zhiyi Liao
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences-Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yaqing Wang
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Ren Lai
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences-Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.
| | - Luke P Lee
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
- Department of Bioengineering, Department of Electrical Engineering and Computer Science, University of California, Berkeley, Berkeley, CA, USA.
- Institute of Quantum Biophysics, Department of Biophysics, Sungkyunkwan University, Suwon, Korea.
| | - Jianhua Qin
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
- University of Science and Technology of China, Hefei, China.
- Suzhou Institute for Advanced Research, University of Science and Technology of China, Suzhou, China.
- University of Chinese Academy of Sciences, Beijing, China.
- Beijing Institute for Stem Cell and Regenerative Medicine, Chinese Academy of Sciences, Beijing, China.
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2
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Rowland RR, Brandariz-Nuñez A. Role of N-linked glycosylation in porcine reproductive and respiratory syndrome virus (PRRSV) infection. J Gen Virol 2024; 105:001994. [PMID: 38776134 PMCID: PMC11165596 DOI: 10.1099/jgv.0.001994] [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: 02/28/2024] [Accepted: 05/14/2024] [Indexed: 05/24/2024] Open
Abstract
Porcine reproductive and respiratory syndrome (PRRSV) is an enveloped single-stranded positive-sense RNA virus and one of the main pathogens that causes the most significant economical losses in the swine-producing countries. PRRSV is currently divided into two distinct species, PRRSV-1 and PRRSV-2. The PRRSV virion envelope is composed of four glycosylated membrane proteins and three non-glycosylated envelope proteins. Previous work has suggested that PRRSV-linked glycans are critical structural components for virus assembly. In addition, it has been proposed that PRRSV glycans are implicated in the interaction with host cells and critical for virus infection. In contrast, recent findings showed that removal of N-glycans from PRRSV does not influence virus infection of permissive cells. Thus, there are not sufficient evidences to indicate compellingly that N-glycans present in the PRRSV envelope play a direct function in viral infection. To gain insights into the role of N-glycosylation in PRRSV infection, we analysed the specific contribution of the envelope protein-linked N-glycans to infection of permissive cells. For this purpose, we used a novel strategy to modify envelope protein-linked N-glycans that consists of production of monoglycosylated PRRSV and viral glycoproteins with different glycan states. Our results showed that removal or alteration of N-glycans from PRRSV affected virus infection. Specifically, we found that complex N-glycans are required for an efficient infection in cell cultures. Furthermore, we found that presence of high mannose type glycans on PRRSV surface is the minimal requirement for a productive viral infection. Our findings also show that PRRSV-1 and PRRSV-2 have different requirements of N-glycan structure for an optimal infection. In addition, we demonstrated that removal of N-glycans from PRRSV does not affect viral attachment, suggesting that these carbohydrates played a major role in regulating viral entry. In agreement with these findings, by performing immunoprecipitation assays and colocalization experiments, we found that N-glycans present in the viral envelope glycoproteins are not required to bind to the essential viral receptor CD163. Finally, we found that the presence of N-glycans in CD163 is not required for PRRSV infection.
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Affiliation(s)
- Raymond R.R. Rowland
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA
| | - Alberto Brandariz-Nuñez
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA
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3
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Heindl MR, Rupp AL, Schwerdtner M, Bestle D, Harbig A, De Rocher A, Schmacke LC, Staker B, Steinmetzer T, Stein DA, Moulton HM, Böttcher-Friebertshäuser E. ACE2 acts as a novel regulator of TMPRSS2-catalyzed proteolytic activation of influenza A virus in airway cells. J Virol 2024; 98:e0010224. [PMID: 38470058 PMCID: PMC11019950 DOI: 10.1128/jvi.00102-24] [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: 01/18/2024] [Accepted: 02/22/2024] [Indexed: 03/13/2024] Open
Abstract
The transmembrane serine protease 2 (TMPRSS2) activates the outer structural proteins of a number of respiratory viruses including influenza A virus (IAV), parainfluenza viruses, and various coronaviruses for membrane fusion. Previous studies showed that TMPRSS2 interacts with the carboxypeptidase angiotensin-converting enzyme 2 (ACE2), a cell surface protein that serves as an entry receptor for some coronaviruses. Here, by using protease activity assays, we determine that ACE2 increases the enzymatic activity of TMPRSS2 in a non-catalytic manner. Furthermore, we demonstrate that ACE2 knockdown inhibits TMPRSS2-mediated cleavage of IAV hemagglutinin (HA) in Calu-3 human airway cells and suppresses virus titers 100- to 1.000-fold. Transient expression of ACE2 in ACE2-deficient cells increased TMPRSS2-mediated HA cleavage and IAV replication. ACE2 knockdown also reduced titers of MERS-CoV and prevented S cleavage by TMPRSS2 in Calu-3 cells. By contrast, proteolytic activation and multicycle replication of IAV with multibasic HA cleavage site typically cleaved by furin were not affected by ACE2 knockdown. Co-immunoprecipitation analysis revealed that ACE2-TMPRSS2 interaction requires the enzymatic activity of TMPRSS2 and the carboxypeptidase domain of ACE2. Together, our data identify ACE2 as a new co-factor or stabilizer of TMPRSS2 activity and as a novel host cell factor involved in proteolytic activation and spread of IAV in human airway cells. Furthermore, our data indicate that ACE2 is involved in the TMPRSS2-catalyzed activation of additional respiratory viruses including MERS-CoV.IMPORTANCEProteolytic cleavage of viral envelope proteins by host cell proteases is essential for the infectivity of many viruses and relevant proteases provide promising drug targets. The transmembrane serine protease 2 (TMPRSS2) has been identified as a major activating protease of several respiratory viruses, including influenza A virus. TMPRSS2 was previously shown to interact with angiotensin-converting enzyme 2 (ACE2). Here, we report the mechanistic details of this interaction. We demonstrate that ACE2 increases or stabilizes the enzymatic activity of TMPRSS2. Furthermore, we describe ACE2 involvement in TMPRSS2-catalyzed cleavage of the influenza A virus hemagglutinin and MERS-CoV spike protein in human airway cells. These findings expand our knowledge of the activation of respiratory viruses by TMPRSS2 and the host cell factors involved. In addition, our results could help to elucidate a physiological role for TMPRSS2.
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Affiliation(s)
| | - Anna-Lena Rupp
- Institute of Virology, Philipps-University, Marburg, Germany
| | | | - Dorothea Bestle
- Institute of Virology, Philipps-University, Marburg, Germany
| | - Anne Harbig
- Institute of Virology, Philipps-University, Marburg, Germany
| | - Amy De Rocher
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
| | - Luna C. Schmacke
- Institute of Pharmaceutical Chemistry, Philipps-University, Marburg, Germany
| | - Bart Staker
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
| | - Torsten Steinmetzer
- Institute of Pharmaceutical Chemistry, Philipps-University, Marburg, Germany
| | - David A. Stein
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - Hong M. Moulton
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
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4
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Awuni E, Abdallah Musah R. Proposing lead compounds for the development of SARS-CoV-2 receptor-binding inhibitors. J Biomol Struct Dyn 2024; 42:2282-2297. [PMID: 37116068 DOI: 10.1080/07391102.2023.2204505] [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: 08/23/2022] [Accepted: 04/11/2023] [Indexed: 04/30/2023]
Abstract
The COVID-19 pandemic has had deleterious effects on the world and demands urgent measures to find therapeutic agents to combat the current and related future outbreaks. The entry of SARS-CoV-2 into the host's cell is facilitated by the interaction between the viral spike receptor-binding domain (sRBD) and the human angiotensin-converting enzyme 2 (hACE2). Although the interface of sRBD involved in the sRBD-hACE2 interaction has been projected as a primary vaccine and drug target, currently no small-molecule drugs have been approved for covid-19 treatment targeting sRBD. Herein structure-based virtual screening and molecular dynamics (MD) simulation strategies were applied to identify novel potential small-molecule binders of the SARS-CoV-2 sRBD from an sRBD-targeted compound library as leads for the development of anti-COVID-19 drugs. The library was initially screened against sRBD by using the GOLD docking program whereby 19 compounds were shortlisted based on docking scores after using a control compound to set the selection cutoff. The stability of each compound in MD simulations was used as a further standard to select four hits namely T4S1820, T4589, E634-1449, and K784-7078. Analyses of simulations data showed that the four compounds remained stably bound to sRBD for ≥ 80 ns with reasonable affinities and interacted with pharmacologically important amino acid residues. The compounds exhibited fair solubility, lipophilicity, and toxicity-propensity characteristics that could be improved through lead optimization regimes. The overall results suggest that the scaffolds of T4S1820, E634-1449, and K784-7078 could serve as seeds for developing potent small-molecule inhibitors of SARS-CoV-2 receptor binding and cell entry.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Elvis Awuni
- Department of Biochemistry, School of Biological Sciences, CANS, University of Cape Coast, Cape Coast, Ghana
| | - Radiatu Abdallah Musah
- Department of Biochemistry, School of Biological Sciences, CANS, University of Cape Coast, Cape Coast, Ghana
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5
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Yang T, Xiao H, Chen X, Zheng L, Guo H, Wang J, Jiang X, Zhang CY, Yang F, Ji X. Characterization of N-glycosylation and its functional role in SIDT1-Mediated RNA uptake. J Biol Chem 2024; 300:105654. [PMID: 38237680 PMCID: PMC10850970 DOI: 10.1016/j.jbc.2024.105654] [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: 11/17/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 02/08/2024] Open
Abstract
The mammalian SID-1 transmembrane family members, SIDT1 and SIDT2, are multipass transmembrane proteins that mediate the cellular uptake and intracellular trafficking of nucleic acids, playing important roles in the immune response and tumorigenesis. Previous work has suggested that human SIDT1 and SIDT2 are N-glycosylated, but the precise site-specific N-glycosylation information and its functional contribution remain unclear. In this study, we use high-resolution liquid chromatography tandem mass spectrometry to comprehensively map the N-glycosites and quantify the N-glycosylation profiles of SIDT1 and SIDT2. Further molecular mechanistic probing elucidates the essential role of N-linked glycans in regulating cell surface expression, RNA binding, protein stability, and RNA uptake of SIDT1. Our results provide crucial information about the potential functional impact of N-glycosylation in the regulation of SIDT1-mediated RNA uptake and provide insights into the molecular mechanisms of this promising nucleic acid delivery system with potential implications for therapeutic applications.
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Affiliation(s)
- Tingting Yang
- The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Haonan Xiao
- The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Xiulan Chen
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Le Zheng
- The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Hangtian Guo
- The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Jiaqi Wang
- The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Xiaohong Jiang
- The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Chen-Yu Zhang
- The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China; Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, Jiangsu, China.
| | - Fuquan Yang
- Key Laboratory of Protein and Peptide Pharmaceuticals & Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
| | - Xiaoyun Ji
- The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China; Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, Jiangsu, China; Institute of Artificial Intelligence Biomedicine, Nanjing University, Nanjing, Jiangsu, China; Engineering Research Center of Protein and Peptide Medicine, Ministry of Education, Nanjing, Jiangsu, China.
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6
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Salgado B, Rivas RB, Pinto D, Sonstegard TS, Carlson DF, Martins K, Bostrom JR, Sinebo Y, Rowland RRR, Brandariz-Nuñez A. Genetically modified pigs lacking CD163 PSTII-domain-coding exon 13 are completely resistant to PRRSV infection. Antiviral Res 2024; 221:105793. [PMID: 38184111 DOI: 10.1016/j.antiviral.2024.105793] [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: 11/13/2023] [Revised: 12/18/2023] [Accepted: 01/02/2024] [Indexed: 01/08/2024]
Abstract
CD163 expressed on cell surface of porcine alveolar macrophages (PAMs) serves as a cellular entry receptor for porcine reproductive and respiratory syndrome virus (PRRSV). The extracellular portion of CD163 contains nine scavenger receptor cysteine-rich (SRCR) and two proline-serine-threonine (PST) domains. Genomic editing of pigs to remove the entire CD163 or just the SRCR5 domain confers resistance to infection with both PRRSV-1 and PRRSV-2 viruses. By performing a mutational analysis of CD163, previous in vitro infection experiments showed resistance to PRRSV infection following deletion of exon 13 which encodes the first 12 amino acids of the 16 amino acid PSTII domain. These findings predicted that removal of exon 13 can be used as a strategy to produce gene-edited pigs fully resistant to PRRSV infection. In this study, to determine whether the deletion of exon 13 is sufficient to confer resistance of pigs to PRRSV infection, we produced pigs possessing a defined CD163 exon 13 deletion (ΔExon13 pigs) and evaluated their susceptibility to viral infection. Wild type (WT) and CD163 modified pigs, placed in the same room, were infected with PRRSV-2. The modified pigs remained PCR and serologically negative for PRRSV throughout the study; whereas the WT pigs supported PRRSV infection and showed PRRSV related pathology. Importantly, our data also suggested that removal of exon 13 did not affect the main physiological function associated with CD163 in vivo. These results demonstrate that a modification of CD163 through a precise deletion of exon 13 provides a strategy for protection against PRRSV infection.
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Affiliation(s)
- Brianna Salgado
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Rafael Bautista Rivas
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Derek Pinto
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | | | | | | | | | | | - Raymond R R Rowland
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Alberto Brandariz-Nuñez
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Champaign, IL, USA.
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7
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Reveret L, Leclerc M, Emond V, Tremblay C, Loiselle A, Bourassa P, Bennett DA, Hébert SS, Calon F. Higher angiotensin-converting enzyme 2 (ACE2) levels in the brain of individuals with Alzheimer's disease. Acta Neuropathol Commun 2023; 11:159. [PMID: 37784209 PMCID: PMC10544218 DOI: 10.1186/s40478-023-01647-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 08/30/2023] [Indexed: 10/04/2023] Open
Abstract
Cognitive decline due to Alzheimer's disease (AD) is frequent in the geriatric population, which has been disproportionately affected by the COVID-19 pandemic. In this study, we investigated the levels of angiotensin-converting enzyme 2 (ACE2), a regulator of the renin-angiotensin system and the main entry receptor of SARS-CoV-2 in host cells, in postmortem parietal cortex samples from two independent AD cohorts, totalling 142 persons. Higher concentrations of ACE2 protein (p < 0.01) and mRNA (p < 0.01) were found in individuals with a neuropathological diagnosis of AD compared to age-matched healthy control subjects. Brain levels of soluble ACE2 were inversely associated with cognitive scores (p = 0.02) and markers of pericytes (PDGFRβ, p = 0.02 and ANPEP, p = 0.007), but positively correlated with concentrations of soluble amyloid-β peptides (Aβ) (p = 0.01) and insoluble phospho-tau (S396/404, p = 0.002). However, no significant differences in ACE2 were observed in the 3xTg-AD mouse model of tau and Aβ neuropathology. Results from immunofluorescence and Western blots showed that ACE2 protein is predominantly localized in microvessels in the mouse brain whereas it is more frequently found in neurons in the human brain. The present data suggest that higher levels of soluble ACE2 in the human brain may contribute to AD, but their role in CNS infection by SARS-CoV-2 remains unclear.
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Affiliation(s)
- Louise Reveret
- Faculty of Pharmacy, Laval University, Quebec, QC, Canada
- CHU de Quebec Research Center, 2705, Boulevard Laurier, Room T2-05, Québec, QC, G1V 4G2, Canada
| | - Manon Leclerc
- Faculty of Pharmacy, Laval University, Quebec, QC, Canada
- CHU de Quebec Research Center, 2705, Boulevard Laurier, Room T2-05, Québec, QC, G1V 4G2, Canada
| | - Vincent Emond
- CHU de Quebec Research Center, 2705, Boulevard Laurier, Room T2-05, Québec, QC, G1V 4G2, Canada
| | - Cyntia Tremblay
- CHU de Quebec Research Center, 2705, Boulevard Laurier, Room T2-05, Québec, QC, G1V 4G2, Canada
| | - Andréanne Loiselle
- CHU de Quebec Research Center, 2705, Boulevard Laurier, Room T2-05, Québec, QC, G1V 4G2, Canada
| | - Philippe Bourassa
- Faculty of Pharmacy, Laval University, Quebec, QC, Canada
- CHU de Quebec Research Center, 2705, Boulevard Laurier, Room T2-05, Québec, QC, G1V 4G2, Canada
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Sébastien S Hébert
- CHU de Quebec Research Center, 2705, Boulevard Laurier, Room T2-05, Québec, QC, G1V 4G2, Canada
- Faculty of Medicine, Laval University, Quebec, QC, Canada
| | - Frédéric Calon
- Faculty of Pharmacy, Laval University, Quebec, QC, Canada.
- CHU de Quebec Research Center, 2705, Boulevard Laurier, Room T2-05, Québec, QC, G1V 4G2, Canada.
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8
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Stocker N, Radzikowska U, Wawrzyniak P, Tan G, Huang M, Ding M, Akdis CA, Sokolowska M. Regulation of angiotensin-converting enzyme 2 isoforms by type 2 inflammation and viral infection in human airway epithelium. Mucosal Immunol 2023; 16:5-16. [PMID: 36642382 PMCID: PMC9836991 DOI: 10.1016/j.mucimm.2022.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 12/06/2022] [Indexed: 01/15/2023]
Abstract
SARS-CoV-2 enters human cells through its main receptor, angiotensin-converting enzyme 2 (ACE2), which constitutes a limiting factor of infection. Recent findings demonstrating novel ACE2 isoforms implicate that this receptor is regulated in a more complex way than previously anticipated. However, it remains unknown how various inflammatory conditions influence the abundance of these ACE2 variants. Hence, we studied expression of ACE2 messenger RNA (mRNA) and protein isoforms, together with its glycosylation and spatial localization in primary human airway epithelium upon allergic inflammation and viral infection. We found that interleukin-13, the main type 2 cytokine, decreased expression of long ACE2 mRNA and reduced glycosylation of full-length ACE2 protein via alteration of N-linked glycosylation process, limiting its availability on the apical side of ciliated cells. House dust mite allergen did not affect the expression of ACE2. Rhinovirus infection increased short ACE2 mRNA, but it did not influence its protein expression. In addition, by screening other SARS-CoV-2 related host molecules, we found that interleukin-13 and rhinovirus significantly regulated mRNA, but not protein of transmembrane serine protease 2 and neuropilin 1. Regulation of ACE2 and other host proteins was comparable in healthy and asthmatic epithelium, underlining the lack of intrinsic differences but dependence on the inflammatory milieu in the airways.
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Affiliation(s)
- Nino Stocker
- Swiss Institute of Allergy and Asthma Research (SIAF), University of Zürich, Davos, Switzerland
| | - Urszula Radzikowska
- Swiss Institute of Allergy and Asthma Research (SIAF), University of Zürich, Davos, Switzerland; Christine Kühne - Center for Allergy Research and Education (CK-CARE), Davos, Switzerland
| | - Paulina Wawrzyniak
- Swiss Institute of Allergy and Asthma Research (SIAF), University of Zürich, Davos, Switzerland; Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zürich, Zürich, Switzerland
| | - Ge Tan
- Swiss Institute of Allergy and Asthma Research (SIAF), University of Zürich, Davos, Switzerland
| | - Mengting Huang
- Swiss Institute of Allergy and Asthma Research (SIAF), University of Zürich, Davos, Switzerland
| | - Mei Ding
- Swiss Institute of Allergy and Asthma Research (SIAF), University of Zürich, Davos, Switzerland
| | - Cezmi A Akdis
- Swiss Institute of Allergy and Asthma Research (SIAF), University of Zürich, Davos, Switzerland; Christine Kühne - Center for Allergy Research and Education (CK-CARE), Davos, Switzerland
| | - Milena Sokolowska
- Swiss Institute of Allergy and Asthma Research (SIAF), University of Zürich, Davos, Switzerland; Christine Kühne - Center for Allergy Research and Education (CK-CARE), Davos, Switzerland.
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9
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The N-Linked Glycosylation Site N191 Is Necessary for PKA Signal Transduction in Eel Follicle-Stimulating Hormone Receptor. Int J Mol Sci 2022; 23:ijms232112792. [PMID: 36361582 PMCID: PMC9655291 DOI: 10.3390/ijms232112792] [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: 10/08/2022] [Revised: 10/20/2022] [Accepted: 10/21/2022] [Indexed: 11/24/2022] Open
Abstract
The follicle-stimulating hormone receptor (FSHR) contains several N-linked glycosylation sites in its extracellular region. We conducted the present study to determine whether conserved glycosylated sites in eel FSHR are necessary for cyclic adenosine monophosphate (cAMP) signal transduction. We used site-directed mutagenesis to induce four mutations (N120Q, N191Q, N272Q, and N288Q) in the N-linked glycosylation sites of eel FSHR. In the eel FSHR wild-type (wt), the cAMP response was gradually increased in a dose-dependent manner (0.01–1500 ng/mL), displaying a high response (approximately 57.5 nM/104 cells) at the Rmax level. Three mutants (N120Q, N272Q, and N288Q) showed a considerably decreased signal transduction as a result of high-ligand treatment, whereas one mutant (N191Q) exhibited a completely impaired signal transduction. The expression level of the N191Q mutant was only 9.2% relative to that of the eel FSHR-wt, indicating a negligible expression level. The expression levels of the N120Q and N272Q mutants were approximately 35.9% and 24% of the FSHG-wt, respectively. The N288Q mutant had an expression level similar to that of the eel FSHR-wt, despite the mostly impaired cAMP responsiveness. The loss of the cell surface agonist-receptor complexes was very rapid in the cells expressing eel FSHR-wt and FSHR-N288Q mutants. Specifically, the N191Q mutant was completely impaired by the loss of cell surface receptors, despite treatment with a high concentration of the agonist. Therefore, we suggest that the N191 site is necessary for cAMP signal transduction. This finding implies that the cAMP response, mediated by G proteins, is directly related to the loss of cell surface receptors as a result of high-agonist treatment.
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10
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Badawi S, Mohamed FE, Alkhofash NR, John A, Ali A, Ali BR. Characterization of ACE2 naturally occurring missense variants: impact on subcellular localization and trafficking. Hum Genomics 2022; 16:35. [PMID: 36056420 PMCID: PMC9438391 DOI: 10.1186/s40246-022-00411-1] [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: 02/10/2022] [Accepted: 07/01/2022] [Indexed: 02/08/2023] Open
Abstract
Background Human angiotensin-converting enzyme 2 (ACE2), a type I transmembrane receptor physiologically acting as a carboxypeptidase enzyme within the renin-angiotensin system (RAS), is a critical mediator of infection by several severe acute respiratory syndrome (SARS) corona viruses. For instance, it has been demonstrated that ACE2 is the primary receptor for the SARS-CoV-2 entry to many human cells through binding to the viral spike S protein. Consequently, genetic variability in ACE2 gene has been suggested to contribute to the variable clinical manifestations in COVID-19. Many of those genetic variations result in missense variants within the amino acid sequence of ACE2. The potential effects of those variations on binding to the spike protein have been speculated and, in some cases, demonstrated experimentally. However, their effects on ACE2 protein folding, trafficking and subcellular targeting have not been established. Results In this study we aimed to examine the potential effects of 28 missense variants (V801G, D785N, R768W, I753T, L731F, L731I, I727V, N720D, R710H, R708W, S692P, E668K, V658I, N638S, A627V, F592L, G575V, A501T, I468V, M383I, G173S, N159S, N149S, D38E, N33D, K26R, I21T, and S19P) distributed across the ACE2 receptor domains on its subcellular trafficking and targeting through combinatorial approach involving in silico analysis and experimental subcellular localization analysis. Our data show that none of the studied missense variants (including 3 variants predicted to be deleterious R768W, G575V, and G173S) has a significant effect on ACE2 intracellular trafficking and subcellular targeting to the plasma membrane. Conclusion Although the selected missense variants display no significant change in ACE2 trafficking and subcellular localization, this does not rule out their effect on viral susceptibility and severity. Further studies are required to investigate the effect of ACE2 variants on its expression, binding, and internalization which might explain the variable clinical manifestations associated with the infection. Supplementary Information The online version contains supplementary material available at 10.1186/s40246-022-00411-1.
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Affiliation(s)
- Sally Badawi
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box: 15551, Al-Ain, United Arab Emirates
| | - Feda E Mohamed
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box: 15551, Al-Ain, United Arab Emirates
| | - Nesreen R Alkhofash
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box: 15551, Al-Ain, United Arab Emirates
| | - Anne John
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box: 15551, Al-Ain, United Arab Emirates
| | - Amanat Ali
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box: 15551, Al-Ain, United Arab Emirates
| | - Bassam R Ali
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box: 15551, Al-Ain, United Arab Emirates. .,Zayed Centre for Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates.
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11
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Hattori T, Saito T, Okuya K, Takahashi Y, Miyamoto H, Kajihara M, Igarashi M, Takada A. Human ACE2 Genetic Polymorphism Affecting SARS-CoV and SARS-CoV-2 Entry into Cells. Microbiol Spectr 2022; 10:e0087022. [PMID: 35862965 PMCID: PMC9430119 DOI: 10.1128/spectrum.00870-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 06/27/2022] [Indexed: 11/29/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 have a single envelope glycoprotein (S protein) that binds to human angiotensin-converting enzyme 2 (ACE2) on the host cell membrane. Previous mutational scanning studies have suggested that some substitutions corresponding to single nucleotide variants (SNVs) in human ACE2 affect the binding affinity to the receptor binding domain (RBD) of the SARS-CoV-2 S protein. However, the importance of these substitutions in actual virus infection is still unclear. In this study, we investigated the effects of the reported ACE2 SNV substitutions on the entry of SARS-CoV and SARS-CoV-2 into cells, using vesicular stomatitis Indiana virus (VSIV) pseudotyped with S proteins of these coronaviruses (CoVs). HEK293T cells transfected with plasmids expressing ACE2 having each SNV substitution were infected with the pseudotyped VSIVs and relative infectivities were determined compared to the cells expressing wild-type ACE2. We found that some of the SNV substitutions positively or negatively affected the infectivities of the pseudotyped viruses. Particularly, the H505R substitution significantly enhanced the infection with the pseudotyped VSIVs, including those having the substitutions found in the S protein RBD of SARS-CoV-2 variants of concern. Our findings suggest that human ACE2 SNVs may potentially affect cell susceptibilities to SARS-CoV and SARS-CoV-2. IMPORTANCE SARS-CoV and SARS-CoV-2 are known to cause severe pneumonia in humans. The S protein of these CoVs binds to the ACE2 molecule on the plasma membrane and mediates virus entry into cells. The interaction between the S protein and ACE2 is thought to be important for host susceptibility to these CoVs. Although previous studies suggested that some SNV substitutions in ACE2 might affect the binding to the S protein, it remains elusive whether these SNV substitutions actually alter the efficiency of the entry of SARS CoVs into cells. We analyzed the impact of the ACE2 SNVs on the cellular entry of SARS CoVs using pseudotyped VSIVs having the S protein on the viral surface. We found that some of the SNV substitutions positively or negatively affected the infectivities of the viruses. Our data support the notion that genetic polymorphisms of ACE2 may potentially influence cell susceptibilities to SARS CoVs.
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Affiliation(s)
- Takanari Hattori
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Takeshi Saito
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Kosuke Okuya
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Yuji Takahashi
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Hiroko Miyamoto
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Masahiro Kajihara
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Manabu Igarashi
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
- International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Ayato Takada
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
- International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
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12
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Tripathi N, Goel B, Bhardwaj N, Vishwakarma RA, Jain SK. Exploring the Potential of Chemical Inhibitors for Targeting Post-translational Glycosylation of Coronavirus (SARS-CoV-2). ACS OMEGA 2022; 7:27038-27051. [PMID: 35937682 PMCID: PMC9344791 DOI: 10.1021/acsomega.2c02345] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 07/08/2022] [Indexed: 06/09/2023]
Abstract
The Spike (S) protein of SARS-CoV-2 expressed on the viral cell surface is of particular importance as it facilitates viral entry into the host cells. The S protein is heavily glycosylated with 22 N-glycosylation sites and a few N-glycosylation sites. During the viral surface protein synthesis via the host ribosomal machinery, glycosylation is an essential step in post-translational modifications (PTMs) and consequently vital for its life cycle, structure, immune evasion, and cell infection. Interestingly, the S protein of SARS-CoV-2 and the host receptor protein, ACE2, are also extensively glycosylated and these surface glycans are critical for the viral-host cell interaction for viral entry. The glycosylation pathway of both virus (hijacked from the host biosynthetic machinery) and target cells crucially affect SARS-CoV-2 infection at different levels. For example, the glycosaminoglycans (GAGs) of host cells serve as a cofactor as they interact with the receptor-binding domain (RBD) of S-glycoprotein and play a protective role in host immune evasion via masking the viral peptide epitopes. Hence, the post-translational glycan biosynthesis, processing, and transport events could be potential targets for developing therapeutic drugs and vaccines. Especially, inhibition of the N-glycan biosynthesis pathway amplifies S protein proteolysis and, thus, blocks viral entry. The chemical inhibitors of SARS-CoV-2 glycosylation could be evaluated for Covid-19. In this review, we discuss the current status of the chemical inhibitors (both natural and synthetically designed inhibitors) of viral glycosylation for Covid-19 and provide a future perspective. It could be an important strategy in targeting the various emerging SARS-CoV-2 variants of concern (VOCs), as these inhibitors are postulated to aid in reducing the viral load as well as infectivity.
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Affiliation(s)
- Nancy Tripathi
- Department
of Pharmaceutical Engineering and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005, Uttar Pradesh, India
| | - Bharat Goel
- Department
of Pharmaceutical Engineering and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005, Uttar Pradesh, India
| | - Nivedita Bhardwaj
- Department
of Pharmaceutical Engineering and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005, Uttar Pradesh, India
| | - Ram A. Vishwakarma
- Council
of Scientific and Industrial Research, Anusandhan
Bhavan, Rafi Marg, New Delhi 110001, India
| | - Shreyans K. Jain
- Department
of Pharmaceutical Engineering and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005, Uttar Pradesh, India
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13
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Stoian AM, Rowland RR, Brandariz-Nuñez A. Identification of CD163 regions that are required for porcine reproductive and respiratory syndrome virus (PRRSV) infection but not for binding to viral envelope glycoproteins. Virology 2022; 574:71-83. [DOI: 10.1016/j.virol.2022.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/21/2022] [Accepted: 07/21/2022] [Indexed: 11/25/2022]
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14
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de Haas P, de Jonge MI, Koenen HJPM, Joosten B, Janssen MCH, de Boer L, Hendriks WJAJ, Lefeber DJ, Cambi A. Evaluation of Cell Models to Study Monocyte Functions in PMM2 Congenital Disorders of Glycosylation. Front Immunol 2022; 13:869031. [PMID: 35603178 PMCID: PMC9121068 DOI: 10.3389/fimmu.2022.869031] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 04/12/2022] [Indexed: 12/02/2022] Open
Abstract
Congenital disorders of glycosylation (CDG) are inherited metabolic diseases characterized by mutations in enzymes involved in different steps of protein glycosylation, leading to aberrant synthesis, attachment or processing of glycans. Recently, immunological dysfunctions in several CDG types have been increasingly documented. Despite these observations, detailed studies on immune cell dysfunction in PMM2-CDG and other CDG types are still scarce. Studying PMM2-CDG patient immune cells is challenging due to limited availability of patient material, which is a result of the low incidence of the disease and the often young age of the subjects. Dedicated immune cell models, mimicking PMM2-CDG, could circumvent many of these problems and facilitate research into the mechanisms of immune dysfunction. Here we provide initial observations about the immunophenotype and the phagocytic function of primary PMM2-CDG monocytes. Furthermore, we assessed the suitability of two different glycosylation-impaired human monocyte models: tunicamycin-treated THP-1 monocytes and PMM2 knockdown THP-1 monocytes induced by shRNAs. We found no significant differences in primary monocyte subpopulations of PMM2-CDG patients as compared to healthy individuals but we did observe anomalous surface glycosylation patterns in PMM2-CDG patient monocytes as determined using fluorescent lectin binding. We also looked at the capacity of monocytes to bind and internalize fungal particles and found a slightly increased uptake of C. albicans by PMM2-CDG monocytes as compared to healthy monocytes. Tunicamycin-treated THP-1 monocytes showed a highly decreased uptake of fungal particles, accompanied by a strong decrease in glycosylation levels and a high induction of ER stress. In contrast and despite a drastic reduction of the PMM2 enzyme activity, PMM2 knockdown THP-1 monocytes showed no changes in global surface glycosylation levels, levels of fungal particle uptake similar to control monocytes, and no ER stress induction. Collectively, these initial observations suggest that the absence of ER stress in PMM2 knockdown THP-1 cells make this model superior over tunicamycin-treated THP-1 cells and more comparable to primary PMM2-CDG monocytes. Further development and exploitation of CDG monocyte models will be essential for future in-depth studies to ultimately unravel the mechanisms of immune dysfunction in CDG.
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Affiliation(s)
- Paola de Haas
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Marien I. de Jonge
- Department of Laboratory Medicine, Laboratory of Medical Immunology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Hans J. P. M. Koenen
- Department of Laboratory Medicine, Laboratory of Medical Immunology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Ben Joosten
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Mirian C. H. Janssen
- Department of Rehabilitation, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Internal Medicine, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | - Lonneke de Boer
- Department of Paediatrics, Radboudumc Amalia Children’s Hospital, Nijmegen, Netherlands
| | - Wiljan J. A. J. Hendriks
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Dirk J. Lefeber
- Department of Laboratory Medicine, Translational Metabolic Laboratory, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | - Alessandra Cambi
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
- *Correspondence: Alessandra Cambi,
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15
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Stoian AMM, Rowland RRR, Brandariz-Nuñez A. Mutations within scavenger receptor cysteine-rich (SRCR) protein domain 5 of porcine CD163 involved in infection with porcine reproductive and respiratory syndrome virus (PRRS). J Gen Virol 2022; 103. [PMID: 35506985 DOI: 10.1099/jgv.0.001740] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
CD163, a macrophage-specific membrane scavenger receptor, serves as a cellular entry receptor for porcine reproductive and respiratory syndrome virus (PRRSV). The removal of scavenger receptor cysteine-rich (SRCR) domain 5 (SRCR5) of CD163 is sufficient to make transfected cells or genetically modified pigs resistant to PRRSV-1 and PRRSV-2 genotypes, and substitution of SRCR5 with SRCR8 from human CD163-like protein (hCD163L1) confers resistance to PRRSV-1 but not PRRSV-2 isolates. However, the specific regions within the SRCR5 polypeptide involved in PRRSV infection remain largely unknown. In this report, we performed mutational studies in order to identify which regions or amino acid sequences in the SRCR5 domain are critical for PRRSV infection. The approach used in this study was to make proline-arginine (PR) insertions along the SRCR5 polypeptide. Constructs were transfected into HEK293T cells, and then evaluated for infection with PRRSV-2 or PRRSV-1. For PRRSV-2, four PR insertions located after amino acids 8 (PR-9), 47 (PR-48), 54 (PR-55), and 99 (PR-100) had the greatest impact on infection. For PRRSV-1, insertions after amino acids 57 (PR-58) and 99 (PR-100) were critical. Computer simulations based on the crystal structure of SRCR5 showed that the mutations that affected infection localized to a similar region on the surface of the 3-D structure. Specifically, we found two surface patches that are essential for PRRSV infection. PR-58 and PR-55, which were separated by only three amino acids, had reciprocal effects on PRRSV-1 and PRRSV-2. Substitution of Glu-58 with Lys-58 reduced PRRSV-1 infection without affecting PRRSV-2, which partially explains the resistance to PRRSV-1 caused by the SRCR5 replacement with the homolog human SRCR8 previously observed. Finally, resistance to infection was observed following the disruption of any of the four conserved disulfide bonds within SRCR5. In summary, the results confirm that there are distinct differences between PRRSV-1 and PRRSV-2 on recognition of CD163; however, all mutations that affect infection locate on a similar region on the same face of SRCR5.
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Affiliation(s)
- Ana M M Stoian
- School of Medicine, Department of Medial Microbiology and Immunology, University of California Davis, Davis, CA, USA
| | - Raymond R R Rowland
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Alberto Brandariz-Nuñez
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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