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Liao Y, Wang H, Liao H, Sun Y, Tan L, Song C, Qiu X, Ding C. Classification, replication, and transcription of Nidovirales. Front Microbiol 2024; 14:1291761. [PMID: 38328580 PMCID: PMC10847374 DOI: 10.3389/fmicb.2023.1291761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 11/06/2023] [Indexed: 02/09/2024] Open
Abstract
Nidovirales is one order of RNA virus, with the largest single-stranded positive sense RNA genome enwrapped with membrane envelope. It comprises four families (Arterividae, Mesoniviridae, Roniviridae, and Coronaviridae) and has been circulating in humans and animals for almost one century, posing great threat to livestock and poultry,as well as to public health. Nidovirales shares similar life cycle: attachment to cell surface, entry, primary translation of replicases, viral RNA replication in cytoplasm, translation of viral proteins, virion assembly, budding, and release. The viral RNA synthesis is the critical step during infection, including genomic RNA (gRNA) replication and subgenomic mRNAs (sg mRNAs) transcription. gRNA replication requires the synthesis of a negative sense full-length RNA intermediate, while the sg mRNAs transcription involves the synthesis of a nested set of negative sense subgenomic intermediates by a discontinuous strategy. This RNA synthesis process is mediated by the viral replication/transcription complex (RTC), which consists of several enzymatic replicases derived from the polyprotein 1a and polyprotein 1ab and several cellular proteins. These replicases and host factors represent the optimal potential therapeutic targets. Hereby, we summarize the Nidovirales classification, associated diseases, "replication organelle," replication and transcription mechanisms, as well as related regulatory factors.
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Affiliation(s)
- Ying Liao
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Huan Wang
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Huiyu Liao
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yingjie Sun
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Lei Tan
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Cuiping Song
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Xusheng Qiu
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Chan Ding
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
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Gavilán E, Medina-Guzman R, Bahatyrevich-Kharitonik B, Ruano D. Protein Quality Control Systems and ER Stress as Key Players in SARS-CoV-2-Induced Neurodegeneration. Cells 2024; 13:123. [PMID: 38247815 PMCID: PMC10814689 DOI: 10.3390/cells13020123] [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: 11/29/2023] [Revised: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 01/23/2024] Open
Abstract
The COVID-19 pandemic has brought to the forefront the intricate relationship between SARS-CoV-2 and its impact on neurological complications, including potential links to neurodegenerative processes, characterized by a dysfunction of the protein quality control systems and ER stress. This review article explores the role of protein quality control systems, such as the Unfolded Protein Response (UPR), the Endoplasmic Reticulum-Associated Degradation (ERAD), the Ubiquitin-Proteasome System (UPS), autophagy and the molecular chaperones, in SARS-CoV-2 infection. Our hypothesis suggests that SARS-CoV-2 produces ER stress and exploits the protein quality control systems, leading to a disruption in proteostasis that cannot be solved by the host cell. This disruption culminates in cell death and may represent a link between SARS-CoV-2 and neurodegeneration.
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Affiliation(s)
- Elena Gavilán
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla (US), 41012 Sevilla, Spain; (R.M.-G.); (B.B.-K.); (D.R.)
- Instituto de Biomedicina de Sevilla, IBIS, Hospital Universitario Virgen del Rocío, Junta de Andalucía, CSIC, University of Seville (US), 41013 Sevilla, Spain
| | - Rafael Medina-Guzman
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla (US), 41012 Sevilla, Spain; (R.M.-G.); (B.B.-K.); (D.R.)
| | - Bazhena Bahatyrevich-Kharitonik
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla (US), 41012 Sevilla, Spain; (R.M.-G.); (B.B.-K.); (D.R.)
- Instituto de Biomedicina de Sevilla, IBIS, Hospital Universitario Virgen del Rocío, Junta de Andalucía, CSIC, University of Seville (US), 41013 Sevilla, Spain
| | - Diego Ruano
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla (US), 41012 Sevilla, Spain; (R.M.-G.); (B.B.-K.); (D.R.)
- Instituto de Biomedicina de Sevilla, IBIS, Hospital Universitario Virgen del Rocío, Junta de Andalucía, CSIC, University of Seville (US), 41013 Sevilla, Spain
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3
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Cesar-Silva D, Pereira-Dutra FS, Giannini ALM, Maya-Monteiro CM, de Almeida CJG. Lipid compartments and lipid metabolism as therapeutic targets against coronavirus. Front Immunol 2023; 14:1268854. [PMID: 38106410 PMCID: PMC10722172 DOI: 10.3389/fimmu.2023.1268854] [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: 07/28/2023] [Accepted: 10/24/2023] [Indexed: 12/19/2023] Open
Abstract
Lipids perform a series of cellular functions, establishing cell and organelles' boundaries, organizing signaling platforms, and creating compartments where specific reactions occur. Moreover, lipids store energy and act as secondary messengers whose distribution is tightly regulated. Disruption of lipid metabolism is associated with many diseases, including those caused by viruses. In this scenario, lipids can favor virus replication and are not solely used as pathogens' energy source. In contrast, cells can counteract viruses using lipids as weapons. In this review, we discuss the available data on how coronaviruses profit from cellular lipid compartments and why targeting lipid metabolism may be a powerful strategy to fight these cellular parasites. We also provide a formidable collection of data on the pharmacological approaches targeting lipid metabolism to impair and treat coronavirus infection.
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Affiliation(s)
- Daniella Cesar-Silva
- Laboratory of Immunopharmacology, Department of Genetics, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Filipe S. Pereira-Dutra
- Laboratory of Immunopharmacology, Department of Genetics, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Ana Lucia Moraes Giannini
- Laboratory of Functional Genomics and Signal Transduction, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Clarissa M. Maya-Monteiro
- Laboratory of Immunopharmacology, Department of Genetics, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
- Laboratory of Endocrinology and Department of Endocrinology and Metabolism, Amsterdam University Medical Centers (UMC), University of Amsterdam, Amsterdam, Netherlands
| | - Cecília Jacques G. de Almeida
- Laboratory of Immunopharmacology, Department of Genetics, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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4
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Li S, Li X, Liang H, Yu K, Zhai J, Xue M, Luo Z, Zheng C, Zhang H. SARS-CoV-2 ORF7a blocked autophagy flux by intervening in the fusion between autophagosome and lysosome to promote viral infection and pathogenesis. J Med Virol 2023; 95:e29200. [PMID: 37916857 DOI: 10.1002/jmv.29200] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 10/09/2023] [Accepted: 10/16/2023] [Indexed: 11/03/2023]
Abstract
The coronavirus disease 2019 (COVID-19) continues to pose a major threat to public health worldwide. Although many studies have clarified the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection process, the underlying mechanisms of viral invasion and immune evasion were still unclear. This study focused on SARS-CoV-2 ORF7a (open reading frame-7a), one of the essential open reading frames (ORFs) in infection and pathogenesis. First, by analyzing its physical and chemical characteristics, SARS-CoV-2 ORF7a is an unstable hydrophobic transmembrane protein. Then, the ORF7a transmembrane domain three-dimensional crystal structure model was predicted and verified. SARS-CoV-2 ORF7a localized in the endoplasmic reticulum and participated in the autophagy-lysosome pathway via interacting with p62. In addition, we elucidated the underlying molecular mechanisms by which ORF7a intercepted autophagic flux, promoted double membrane vesicle formation, and evaded host autophagy-lysosome degradation and antiviral innate immunity. This study demonstrated that ORF7a could be a therapeutic target, and Glecaprevir may be a potential drug against SARS-CoV-2 by targeting ORF7a. A comprehensive understanding of ORF7a's functions may contribute to developing novel therapies and clinical drugs against COVID-19.
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Affiliation(s)
- Shun Li
- Department of Spine Surgery, People's Hospital of Longhua, Affiliated Hospital of Southern Medical University, Shenzhen, China
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, Sichuan, China
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Xiaobo Li
- Department of Respiratory, Chengdu Seventh People's Hospital (Affiliated Cancer Hospital of Chengdu Medical College), Chengdu, Sichuan, China
| | - Haowei Liang
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, Sichuan, China
| | - Kuike Yu
- Department of Spine Surgery, People's Hospital of Longhua, Affiliated Hospital of Southern Medical University, Shenzhen, China
| | - Jingbo Zhai
- Key Laboratory of Zoonose Prevention and Control at Universities of Inner Mongolia Autonomous Region, Medical College, Inner Mongolia Minzu University, Tongliao, China
| | - Mengzhou Xue
- Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Zhuojing Luo
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
- Institute of Orthopedic Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Chunfu Zheng
- Department of Microbiology, Immunology & Infection Diseases, University of Calgary, Calgary, Canada
| | - Hao Zhang
- Department of Spine Surgery, People's Hospital of Longhua, Affiliated Hospital of Southern Medical University, Shenzhen, China
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Malireddi RKS, Bynigeri RR, Mall R, Connelly JP, Pruett-Miller SM, Kanneganti TD. Inflammatory cell death, PANoptosis, screen identifies host factors in coronavirus innate immune response as therapeutic targets. Commun Biol 2023; 6:1071. [PMID: 37864059 PMCID: PMC10589293 DOI: 10.1038/s42003-023-05414-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 10/03/2023] [Indexed: 10/22/2023] Open
Abstract
The COVID-19 pandemic, caused by the β-coronavirus (β-CoV) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to cause significant global morbidity and mortality. While vaccines have reduced the overall number of severe infections, there remains an incomplete understanding of viral entry and innate immune activation, which can drive pathology. Innate immune responses characterized by positive feedback between cell death and cytokine release can amplify the inflammatory cytokine storm during β-CoV-mediated infection to drive pathology. Therefore, there remains an unmet need to understand innate immune processes in response to β-CoV infections to identify therapeutic strategies. To address this gap, here we used an MHV model and developed a whole genome CRISPR-Cas9 screening approach to elucidate host molecules required for β-CoV infection and inflammatory cell death, PANoptosis, in macrophages, a sentinel innate immune cell. Our screen was validated through the identification of the known MHV receptor Ceacam1 as the top hit, and its deletion significantly reduced viral replication due to loss of viral entry, resulting in a downstream reduction in MHV-induced cell death. Moreover, this screen identified several other host factors required for MHV infection-induced macrophage cell death. Overall, these findings demonstrate the feasibility and power of using genome-wide PANoptosis screens in macrophage cell lines to accelerate the discovery of key host factors in innate immune processes and suggest new targets for therapeutic development to prevent β-CoV-induced pathology.
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Affiliation(s)
- R K Subbarao Malireddi
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Ratnakar R Bynigeri
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Raghvendra Mall
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Biotechnology Research Center, Technology Innovation Institute, Abu Dhabi, P.O. Box 9639, United Arab Emirates
| | - Jon P Connelly
- Center for Advanced Genome Engineering (CAGE), St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Shondra M Pruett-Miller
- Center for Advanced Genome Engineering (CAGE), St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
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Cerracchio C, Salvatore MM, Del Sorbo L, Serra F, Amoroso MG, DellaGreca M, Nicoletti R, Andolfi A, Fiorito F. In Vitro Evaluation of Antiviral Activities of Funicone-like Compounds Vermistatin and Penisimplicissin against Canine Coronavirus Infection. Antibiotics (Basel) 2023; 12:1319. [PMID: 37627739 PMCID: PMC10451237 DOI: 10.3390/antibiotics12081319] [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: 07/27/2023] [Revised: 08/11/2023] [Accepted: 08/12/2023] [Indexed: 08/27/2023] Open
Abstract
Recent studies have demonstrated that 3-O-methylfunicone (OMF), a fungal secondary metabolite from Talaromyces pinophilus belonging to the class of funicone-like compounds, has antiviral activity against canine coronaviruses (CCoV), which causes enteritis in dogs. Herein, we selected two additional funicone-like compounds named vermistatin (VER) and penisimplicissin (PS) and investigated their inhibitory activity towards CCoV infection. Thus, both compounds have been tested for their cytotoxicity and for antiviral activity against CCoV in A72 cells, a fibrosarcoma cell line suitable for investigating CCoV. Our findings showed an increase in cell viability, with an improvement of morphological features in CCoV-infected cells at the non-toxic doses of 1 μM for VER and 0.5 μM for PS. In addition, we observed that these compounds caused a strong inhibition in the expression of the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor which is activated during CCoV infection. Our results also showed the alkalinization of lysosomes in the presence of VER or PS, which may be involved in the observed antiviral activities.
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Affiliation(s)
- Claudia Cerracchio
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, 80137 Naples, Italy; (C.C.); (L.D.S.)
| | - Maria Michela Salvatore
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy; (M.M.S.); (M.D.)
- Institute for Sustainable Plant Protection, National Research Council, 80055 Portici, Italy
| | - Luca Del Sorbo
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, 80137 Naples, Italy; (C.C.); (L.D.S.)
| | - Francesco Serra
- Istituto Zooprofilattico Sperimentale del Mezzogiorno, Unit of Virology, Department of Animal Health, 80055 Portici, Italy;
| | - Maria Grazia Amoroso
- Istituto Zooprofilattico Sperimentale del Mezzogiorno, Unit of Virology, Department of Animal Health, 80055 Portici, Italy;
| | - Marina DellaGreca
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy; (M.M.S.); (M.D.)
| | - Rosario Nicoletti
- Department of Agricultural Sciences, University of Naples Federico II, 80055 Portici, Italy;
- Council for Agricultural Research and Economics, Research Centre for Olive, Fruit and Citrus Crops, 81100 Caserta, Italy
| | - Anna Andolfi
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy; (M.M.S.); (M.D.)
- BAT Center-Interuniversity Center for Studies on Bioinspired Agro-Environmental Technology, University of Naples Federico II, 80055 Portici, Italy
| | - Filomena Fiorito
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, 80137 Naples, Italy; (C.C.); (L.D.S.)
- BAT Center-Interuniversity Center for Studies on Bioinspired Agro-Environmental Technology, University of Naples Federico II, 80055 Portici, Italy
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Lotti V, Lagni A, Diani E, Sorio C, Gibellini D. Crosslink between SARS-CoV-2 replication and cystic fibrosis hallmarks. Front Microbiol 2023; 14:1162470. [PMID: 37250046 PMCID: PMC10213757 DOI: 10.3389/fmicb.2023.1162470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 04/21/2023] [Indexed: 05/31/2023] Open
Abstract
SARS-CoV-2, the etiological cause of the COVID-19 pandemic, can cause severe illness in certain at-risk populations, including people with cystic fibrosis (pwCF). Nevertheless, several studies indicated that pwCF do not have higher risks of SARS-CoV-2 infection nor do they demonstrate worse clinical outcomes than those of the general population. Recent in vitro studies indicate cellular and molecular processes to be significant drivers in pwCF lower infection rates and milder symptoms than expected in cases of SARS-CoV-2 infection. These range from cytokine releases to biochemical alterations leading to morphological rearrangements inside the cells associated with CFTR impairment. Based on available data, the reported low incidence of SARS-CoV-2 infection among pwCF is likely a result of several variables linked to CFTR dysfunction, such as thick mucus, IL-6 reduction, altered ACE2 and TMPRSS2 processing and/or functioning, defective anions exchange, and autophagosome formation. An extensive analysis of the relation between SARS-CoV-2 infection and pwCF is essential to elucidate the mechanisms involved in this lower-than-expected infection impact and to possibly suggest potential new antiviral strategies.
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Affiliation(s)
- Virginia Lotti
- Microbiology Section, Department of Diagnostic and Public Health, University of Verona, Verona, Italy
| | - Anna Lagni
- Microbiology Section, Department of Diagnostic and Public Health, University of Verona, Verona, Italy
| | - Erica Diani
- Microbiology Section, Department of Diagnostic and Public Health, University of Verona, Verona, Italy
| | - Claudio Sorio
- General Pathology Section, Department of Medicine, University of Verona, Verona, Italy
| | - Davide Gibellini
- Microbiology Section, Department of Diagnostic and Public Health, University of Verona, Verona, Italy
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Long COVID and the Neuroendocrinology of Microbial Translocation Outside the GI Tract: Some Treatment Strategies. ENDOCRINES 2022. [DOI: 10.3390/endocrines3040058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Similar to previous pandemics, COVID-19 has been succeeded by well-documented post-infectious sequelae, including chronic fatigue, cough, shortness of breath, myalgia, and concentration difficulties, which may last 5 to 12 weeks or longer after the acute phase of illness. Both the psychological stress of SARS-CoV-2 infection and being diagnosed with COVID-19 can upregulate cortisol, a stress hormone that disrupts the efferocytosis effectors, macrophages, and natural killer cells, leading to the excessive accumulation of senescent cells and disruption of biological barriers. This has been well-established in cancer patients who often experience unrelenting fatigue as well as gut and blood–brain barrier dysfunction upon treatment with senescence-inducing radiation or chemotherapy. In our previous research from 2020 and 2021, we linked COVID-19 to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) via angiotensin II upregulation, premature endothelial senescence, intestinal barrier dysfunction, and microbial translocation from the gastrointestinal tract into the systemic circulation. In 2021 and 2022, these hypotheses were validated and SARS-CoV-2-induced cellular senescence as well as microbial translocation were documented in both acute SARS-CoV-2 infection, long COVID, and ME/CFS, connecting intestinal barrier dysfunction to disabling fatigue and specific infectious events. The purpose of this narrative review is to summarize what is currently known about host immune responses to translocated gut microbes and how these responses relate to fatiguing illnesses, including long COVID. To accomplish this goal, we examine the role of intestinal and blood–brain barriers in long COVID and other illnesses typified by chronic fatigue, with a special emphasis on commensal microbes functioning as viral reservoirs. Furthermore, we discuss the role of SARS-CoV-2/Mycoplasma coinfection in dysfunctional efferocytosis, emphasizing some potential novel treatment strategies, including the use of senotherapeutic drugs, HMGB1 inhibitors, Toll-like receptor 4 (TLR4) blockers, and membrane lipid replacement.
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Alonzi T, Aiello A, Repele F, Falasca L, Francalancia M, Garbuglia AR, Delogu G, Nicastri E, Piacentini M, Goletti D. Cysteamine exerts in vitro antiviral activity against the SARS-CoV-2 Delta and Omicron variants. Cell Death Dis 2022; 8:288. [PMID: 35705564 PMCID: PMC9199336 DOI: 10.1038/s41420-022-01080-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/27/2022] [Accepted: 06/01/2022] [Indexed: 11/28/2022]
Abstract
The novel SARS-CoV-2 variants of concern (VOC) represent a considerable global alarm because their mutations are known to affect transmissibility and cause immune escape. While preventing severe disease and deaths, the available vaccines do not avoid infection; therefore, COVID-19 disease management still requires effective therapies. We have recently reported that the aminothiol cysteamine, a drug already applied to humans, exerts direct antiviral activity against SARS-CoV-2 and has in vitro immunomodulatory effect. To evaluate whether this compound exerts antiviral effects also against SARS-CoV-2 variants, we performed different infected cell-based assays using Wild type, Delta, or Omicron VOC. We found that cysteamine significantly reduces the cytopathic effect induced by SARS-CoV-2 Wild type strain and Delta variant in Vero E6 cells. On the other hand, cysteamine had no effects on the survival of cells infected with the Omicron variant, due to the lack of cytotoxicity on Vero E6 cells, at least when infected at MOI = 0.001 for 72 h. Moreover, cysteamine significantly reduced the production of Wild type, Delta, and Omicron variants as measured by the virus released in the culture media (Vero E6 and Calu-3 cells) and by transmission electron microscopy analysis (Vero E6 cells). Notably, cysteamine is more effective in inhibiting the Omicron rather than Delta or Wild type viruses, with an 80% inhibition of Omicron production compared to 40% of Wild type and Delta variant. Overall, our findings demonstrate that cysteamine exerts direct antiviral actions against SARS-CoV-2 Delta and Omicron variants, in addition to the Wild type virus. Our data further demonstrate that cysteamine is a good candidate as repurposing drug for the treatment of SARS-CoV-2 infection for the present and, likely, the future VOC and, therefore, it would be important to investigate its clinical relevance in randomized clinical trials.
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Affiliation(s)
- Tonino Alonzi
- National Institute for Infectious Diseases "L. Spallanzani"-IRCCS, Rome, Italy
| | - Alessandra Aiello
- National Institute for Infectious Diseases "L. Spallanzani"-IRCCS, Rome, Italy
| | - Federica Repele
- National Institute for Infectious Diseases "L. Spallanzani"-IRCCS, Rome, Italy
| | - Laura Falasca
- National Institute for Infectious Diseases "L. Spallanzani"-IRCCS, Rome, Italy
| | | | - Anna Rosa Garbuglia
- National Institute for Infectious Diseases "L. Spallanzani"-IRCCS, Rome, Italy
| | - Giovanni Delogu
- Institute of Microbiology, Università Cattolica del Sacro Cuore - Fondazione Policlinico Gemelli, Rome, Italy.,Mater Olbia Hospital, Olbia, Italy
| | - Emanuele Nicastri
- National Institute for Infectious Diseases "L. Spallanzani"-IRCCS, Rome, Italy
| | - Mauro Piacentini
- National Institute for Infectious Diseases "L. Spallanzani"-IRCCS, Rome, Italy. .,Department of Biology, University of Rome "Tor Vergata", Rome, Italy.
| | - Delia Goletti
- National Institute for Infectious Diseases "L. Spallanzani"-IRCCS, Rome, Italy
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