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1.
mBio ; 12(6): e0334721, 2021 12 21.
Article in English | MEDLINE | ID: covidwho-1599212

ABSTRACT

The world was unprepared for coronavirus disease 2019 (COVID-19) and remains ill-equipped for future pandemics. While unprecedented strides have been made developing vaccines and treatments for COVID-19, there remains a need for highly effective and widely available regimens for ambulatory use for novel coronaviruses and other viral pathogens. We posit that a priority is to develop pan-family drug cocktails to enhance potency, limit toxicity, and avoid drug resistance. We urge cocktail development for all viruses with pandemic potential both in the short term (<1 to 2 years) and longer term with pairs of drugs in advanced clinical testing or repurposed agents approved for other indications. While significant efforts were launched against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in vitro and in the clinic, many studies employed solo drugs and had disappointing results. Here, we review drug combination studies against SARS-CoV-2 and other viruses and introduce a model-driven approach to assess drug pairs with the highest likelihood of clinical efficacy. Where component agents lack sufficient potency, we advocate for synergistic combinations to achieve therapeutic levels. We also discuss issues that stymied therapeutic progress against COVID-19, including testing of agents with low likelihood of efficacy late in clinical disease and lack of focus on developing virologic surrogate endpoints. There is a need to expedite efficient clinical trials testing drug combinations that could be taken at home by recently infected individuals and exposed contacts as early as possible during the next pandemic, whether caused by a coronavirus or another viral pathogen. The approach herein represents a proactive plan for global viral pandemic preparedness.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus/drug effects , Drug Combinations , Animals , COVID-19/drug therapy , Coronavirus/classification , Coronavirus/pathogenicity , Coronavirus Infections/drug therapy , Humans , Mice , Pandemics/prevention & control , SARS-CoV-2/drug effects
2.
Molecules ; 26(21)2021 Oct 26.
Article in English | MEDLINE | ID: covidwho-1488676

ABSTRACT

A novel human coronavirus prompted considerable worry at the end of the year 2019. Now, it represents a significant global health and economic burden. The newly emerged coronavirus disease caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the primary reason for the COVID-19 global pandemic. According to recent global figures, COVID-19 has caused approximately 243.3 million illnesses and 4.9 million deaths. Several human cell receptors are involved in the virus identification of the host cells and entering them. Hence, understanding how the virus binds to host-cell receptors is crucial for developing antiviral treatments and vaccines. The current work aimed to determine the multiple host-cell receptors that bind with SARS-CoV-2 and other human coronaviruses for the purpose of cell entry. Extensive research is needed using neutralizing antibodies, natural chemicals, and therapeutic peptides to target those host-cell receptors in extremely susceptible individuals. More research is needed to map SARS-CoV-2 cell entry pathways in order to identify potential viral inhibitors.


Subject(s)
Coronavirus/metabolism , Host Microbial Interactions/physiology , Receptors, Coronavirus/metabolism , Antibodies, Neutralizing , Antiviral Agents/pharmacology , COVID-19 , Coronavirus/pathogenicity , Humans , Receptors, Coronavirus/physiology , Receptors, Virus/metabolism , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization/drug effects
3.
Cell Mol Life Sci ; 78(21-22): 6735-6744, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1377320

ABSTRACT

Kallikrein-related peptidases (KLKs) or kallikreins have been linked to diverse (patho) physiological processes, such as the epidermal desquamation and inflammation, seminal clot liquefaction, neurodegeneration, and cancer. Recent mounting evidence suggests that KLKs also represent important regulators of viral infections. It is well-established that certain enveloped viruses, including influenza and coronaviruses, require proteolytic processing of their hemagglutinin or spike proteins, respectively, to infect host cells. Similarly, the capsid protein of the non-enveloped papillomavirus L1 should be proteolytically cleaved for viral uncoating. Consequently, extracellular or membrane-bound proteases of the host cells are instrumental for viral infections and represent potential targets for drug development. Here, we summarize how extracellular proteolysis mediated by the kallikreins is implicated in the process of influenza (and potentially coronavirus and papillomavirus) entry into host cells. Besides direct proteolytic activation of viruses, KLK5 and 12 promote viral entry indirectly through proteolytic cascade events, like the activation of thrombolytic enzymes that also can process hemagglutinin, while additional functions of KLKs in infection cannot be excluded. In the light of recent evidence, KLKs represent potential host targets for the development of new antivirals. Humanized animal models to validate their key functions in viral infections will be valuable.


Subject(s)
COVID-19/enzymology , COVID-19/virology , Host Microbial Interactions/physiology , Kallikreins/metabolism , SARS-CoV-2 , Virus Diseases/enzymology , Animals , Asthma/etiology , Coronavirus/genetics , Coronavirus/pathogenicity , Coronavirus/physiology , Host Microbial Interactions/genetics , Humans , Orthomyxoviridae/genetics , Orthomyxoviridae/pathogenicity , Orthomyxoviridae/physiology , Papillomavirus Infections/enzymology , Papillomavirus Infections/virology , Picornaviridae Infections/complications , Picornaviridae Infections/enzymology , Picornaviridae Infections/virology , Protein Processing, Post-Translational , Proteolysis , Rhinovirus/pathogenicity , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , SARS-CoV-2/physiology , Varicella Zoster Virus Infection/enzymology , Varicella Zoster Virus Infection/virology , Viral Proteins/genetics , Viral Proteins/metabolism , Virus Diseases/virology , Virus Internalization
4.
Front Immunol ; 12: 708264, 2021.
Article in English | MEDLINE | ID: covidwho-1325532

ABSTRACT

There are still many unanswered questions concerning viral SARS-CoV-2 pathogenesis in COVID-19. Accessory proteins in SARS-CoV-2 consist of eleven viral proteins whose roles during infection are still not completely understood. Here, a review on the current knowledge of SARS-CoV-2 accessory proteins is summarized updating new research that could be critical in understanding SARS-CoV-2 interaction with the host. Some accessory proteins such as ORF3b, ORF6, ORF7a and ORF8 have been shown to be important IFN-I antagonists inducing an impairment in the host immune response. In addition, ORF3a is involved in apoptosis whereas others like ORF9b and ORF9c interact with cellular organelles leading to suppression of the antiviral response in infected cells. However, possible roles of ORF7b and ORF10 are still awaiting to be described. Also, ORF3d has been reassigned. Relevant information on the knowns and the unknowns in these proteins is analyzed, which could be crucial for further understanding of SARS-CoV-2 pathogenesis and to design strategies counteracting their actions evading immune responses in COVID-19.


Subject(s)
COVID-19/immunology , SARS-CoV-2/pathogenicity , Viral Regulatory and Accessory Proteins/immunology , COVID-19/pathology , Coronavirus/metabolism , Coronavirus/pathogenicity , Humans , Immune Evasion , Immunity , Interferons/antagonists & inhibitors , SARS-CoV-2/metabolism , Viral Regulatory and Accessory Proteins/metabolism
5.
Viral Immunol ; 34(9): 597-606, 2021 11.
Article in English | MEDLINE | ID: covidwho-1322606

ABSTRACT

Coronaviruses (CoVs) contribute significantly to the burden of respiratory diseases, frequently as upper respiratory tract infections. Recent emergence of novel coronaviruses in the last few decades has highlighted the potential transmission, disease, and mortality related to these viruses. In this literature review, we shall explore the disease-causing mechanism of the virus through human monocytes and macrophages. Common strains will be discussed; however, this review will center around coronaviruses responsible for epidemics, namely severe acute respiratory syndrome coronavirus (SARS-CoV)-1 and -2 and the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). Macrophages are key players in the immune system and have been found to play a role in the pathogenesis of lethal coronaviruses. In physiology, they are white blood cells that engulf and digest cellular debris, foreign substances, and microbes. They play a critical role in innate immunity and help initiate adaptive immunity. Human coronaviruses utilize various mechanisms to undermine the innate immune response through its interaction with macrophages and monocytes. It is capable of entering immune cells through DPP4 (dipeptidyl-peptidase 4) receptors and antibody-dependent enhancement, delaying initial interferon response which supports robust viral replication. Pathogenesis includes triggering the production of overwhelming pro-inflammatory cytokines that attract other immune cells to the site of infection, which propagate prolonged pro-inflammatory response. The virus has also been found to suppress the release of anti-inflammatory mediators such as IL-10, leading to an aberrant inflammatory response. Elevated serum cytokines are also believed to contribute to pathological features seen in severe disease such as coagulopathy, acute lung injury, and multiorgan failure.


Subject(s)
Coronavirus Infections/immunology , Coronavirus/immunology , Coronavirus/pathogenicity , Immunity, Innate , Macrophages/virology , Monocytes/virology , Animals , Coronavirus/classification , Coronavirus Infections/pathology , Coronavirus Infections/virology , Cytokines/blood , Cytokines/immunology , Humans , Inflammation/immunology , Inflammation/virology , Lung/pathology , Macrophages/immunology , Monocytes/immunology , Virus Replication
6.
Salud Publica Mex ; 63(1, ene-feb): 109-119, 2020 Dec 22.
Article in Spanish | MEDLINE | ID: covidwho-1310298

ABSTRACT

Objetivo. Describir la evidencia sobre la presencia e infectividad de SARS-CoV-2 y otros coronavirus en aguas residuales y su potencial uso como herramienta de vigilancia epidemiológica. Material y métodos. Búsqueda de publicaciones en PubMed y medRxiv desde enero 2003 hasta el 8 de junio de 2020 de acuerdo con la guía de revisiones rápidas de Cochrane. Resultados. Se incluyeron 29 publicaciones. El ARN de SARS-CoV-2 no infectivo se encontró en agua residual hospitalaria, agua residual cruda, tratada y lodos de plantas de tratamiento. Los niveles cuantitativos de ARN viral en agua residual presentan relación con el número de casos de Covid-19. SARS-CoV-1 y otros coronavirus permanecieron infectivos en agua residual cruda hasta por dos días. Conclusiones. Hasta esta revisión no existe evidencia sobre la presencia de virus infectivos de SARS-CoV-2 en agua residual cruda o tratada. La cuantificación de ARN de SARS-CoV-2 en agua residual es útil para la vigilancia epidemiológica.


Subject(s)
RNA, Viral/isolation & purification , SARS-CoV-2/isolation & purification , Waste Water/virology , Wastewater-Based Epidemiological Monitoring , Coronavirus/isolation & purification , Coronavirus/pathogenicity , Mexico , SARS Virus/isolation & purification , SARS Virus/pathogenicity , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Virulence , Water Microbiology
7.
Int J Mol Sci ; 22(13)2021 Jun 29.
Article in English | MEDLINE | ID: covidwho-1304667

ABSTRACT

Amyloid beta (Aß)-induced abnormal neuroinflammation is recognized as a major pathological feature of Alzheimer's disease (AD), which results in memory impairment. Research exploring low-grade systemic inflammation and its impact on the development and progression of neurodegenerative disease has increased. A particular research focus has been whether systemic inflammation arises only as a secondary effect of disease, or it is also a cause of pathology. The inflammasomes, and more specifically the NLRP3 inflammasome, are crucial components of the innate immune system and are usually activated in response to infection or tissue damage. Although inflammasome activation plays critical roles against various pathogens in host defense, overactivation of inflammasome contributes to the pathogenesis of inflammatory diseases, including acute central nervous system (CNS) injuries and chronic neurodegenerative diseases, such as AD. This review summarizes the current literature on the role of the NLRP3 inflammasome in the pathogenesis of AD, and its involvement in infections, particularly SARS-CoV-2. NLRP3 might represent the crossroad between the hypothesized neurodegeneration and the primary COVID-19 infection.


Subject(s)
Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Inflammasomes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Alzheimer Disease/metabolism , Animals , Coronavirus/pathogenicity , Humans , Immunity, Innate , Microglia/metabolism , Virus Diseases/immunology , Virus Diseases/pathology
8.
Int J Mol Sci ; 22(13)2021 Jun 29.
Article in English | MEDLINE | ID: covidwho-1295856

ABSTRACT

Amyloid beta (Aß)-induced abnormal neuroinflammation is recognized as a major pathological feature of Alzheimer's disease (AD), which results in memory impairment. Research exploring low-grade systemic inflammation and its impact on the development and progression of neurodegenerative disease has increased. A particular research focus has been whether systemic inflammation arises only as a secondary effect of disease, or it is also a cause of pathology. The inflammasomes, and more specifically the NLRP3 inflammasome, are crucial components of the innate immune system and are usually activated in response to infection or tissue damage. Although inflammasome activation plays critical roles against various pathogens in host defense, overactivation of inflammasome contributes to the pathogenesis of inflammatory diseases, including acute central nervous system (CNS) injuries and chronic neurodegenerative diseases, such as AD. This review summarizes the current literature on the role of the NLRP3 inflammasome in the pathogenesis of AD, and its involvement in infections, particularly SARS-CoV-2. NLRP3 might represent the crossroad between the hypothesized neurodegeneration and the primary COVID-19 infection.


Subject(s)
Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Inflammasomes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Alzheimer Disease/metabolism , Animals , Coronavirus/pathogenicity , Humans , Immunity, Innate , Microglia/metabolism , Virus Diseases/immunology , Virus Diseases/pathology
9.
Infect Genet Evol ; 93: 104944, 2021 09.
Article in English | MEDLINE | ID: covidwho-1246087

ABSTRACT

Since the emergence of their primitive strains, the complexity surrounding their pathogenesis, constant genetic mutation and translation are contributing factors to the scarcity of a successful vaccine for coronaviruses till moment. Although, the recent announcement of vaccine breakthrough for COVID-19 renews the hope, however, there remains a major challenge of accessibility to urgently match the rapid global therapeutic demand for curtailing the pandemic, thereby creating an impetus for further search. The reassessment of results from a stream of experiments is of enormous importance in identifying bona fide lead-like candidates to fulfil this quest. This review comprehensively highlights the common pathomechanisms and pharmacological targets of HCoV-OC43, SARS-CoV-1, MERS-CoV and SARS-CoV-2, and potent therapeutic potentials from basic and clinical experimental investigations. The implicated targets for the prevention and treatment include the viral proteases (Mpro, PLpro, 3CLpro), viral structural proteins (S- and N-proteins), non-structural proteins (nsp 3, 8, 10, 14, 16), accessory protein (ns12.9), viroporins (3a, E, 8a), enzymes (RdRp, TMPRSS2, ADP-ribosyltransferase, MTase, 2'-O-MTase, TATase, furin, cathepsin, deamidated human triosephosphate isomerase), kinases (MAPK, ERK, PI3K, mTOR, AKT, Abl2), interleukin-6 receptor (IL-6R) and the human host receptor, ACE2. Notably among the 109 overviewed inhibitors include quercetin, eriodictyol, baicalin, luteolin, melatonin, resveratrol and berberine from natural products, GC373, NP164 and HR2P-M2 from peptides, 5F9, m336 and MERS-GD27 from specific human antibodies, imatinib, remdesivir, ivermectin, chloroquine, hydroxychloroquine, nafamostat, interferon-ß and HCQ from repurposing libraries, some iron chelators and traditional medicines. This review represents a model for further translational studies for effective anti-CoV therapeutic designs.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus Infections/etiology , Coronavirus/pathogenicity , Host-Pathogen Interactions , Antiviral Agents/therapeutic use , Coronavirus/drug effects , Coronavirus/metabolism , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Coronavirus OC43, Human/drug effects , Coronavirus OC43, Human/pathogenicity , Humans , Middle East Respiratory Syndrome Coronavirus/drug effects , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Randomized Controlled Trials as Topic , SARS-CoV-2/drug effects , SARS-CoV-2/pathogenicity , Viral Proteins/chemistry , Viral Proteins/genetics , Viral Proteins/metabolism
10.
Viruses ; 13(5)2021 05 18.
Article in English | MEDLINE | ID: covidwho-1234835

ABSTRACT

The ongoing coronavirus disease 2019 (COVID-19) pandemic has had devastating health and socio-economic impacts. Human activities, especially at the wildlife interphase, are at the core of forces driving the emergence of new viral agents. Global surveillance activities have identified bats as the natural hosts of diverse coronaviruses, with other domestic and wildlife animal species possibly acting as intermediate or spillover hosts. The African continent is confronted by several factors that challenge prevention and response to novel disease emergences, such as high species diversity, inadequate health systems, and drastic social and ecosystem changes. We reviewed published animal coronavirus surveillance studies conducted in Africa, specifically summarizing surveillance approaches, species numbers tested, and findings. Far more surveillance has been initiated among bat populations than other wildlife and domestic animals, with nearly 26,000 bat individuals tested. Though coronaviruses have been identified from approximately 7% of the total bats tested, surveillance among other animals identified coronaviruses in less than 1%. In addition to a large undescribed diversity, sequences related to four of the seven human coronaviruses have been reported from African bats. The review highlights research gaps and the disparity in surveillance efforts between different animal groups (particularly potential spillover hosts) and concludes with proposed strategies for improved future biosurveillance.


Subject(s)
Coronavirus Infections/epidemiology , Epidemiological Monitoring/veterinary , Africa/epidemiology , Animals , Animals, Wild/virology , COVID-19/epidemiology , Chiroptera/virology , Coronaviridae/genetics , Coronavirus/pathogenicity , Ecosystem , Genetic Variation , Genome, Viral , Pandemics , Phylogeny , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/genetics
11.
Adv Exp Med Biol ; 1318: 23-39, 2021.
Article in English | MEDLINE | ID: covidwho-1222705

ABSTRACT

The ongoing coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is highly contagious and fatal, posing a direct threat to human health and the global economy. Most strategies to prevent, control, and eradicate COVID-19 are established based on the specific characteristics of the pathogen. The quest for interruption and eradication of COVID-19 has moved research forward in understanding fundamental aspects of the virus genome, proteome, replication mechanisms, and virus-host interactions, which pave the way for the development of effective antiviral drugs and vaccines. This chapter provides an overview of recent progress in human coronavirus taxonomy, molecular features of the SARS-CoV-2 genome and proteome, and virus life cycle.


Subject(s)
COVID-19 , Coronavirus , SARS-CoV-2 , Antiviral Agents/therapeutic use , Classification , Coronavirus/genetics , Coronavirus/pathogenicity , Genome, Viral/genetics , Humans
12.
Biomolecules ; 11(5)2021 04 29.
Article in English | MEDLINE | ID: covidwho-1217049

ABSTRACT

Severely ill coronavirus disease 2019 (COVID-19) patients show elevated concentrations of pro-inflammatory cytokines, a situation commonly known as a cytokine storm. The p38 MAPK receptor is considered a plausible therapeutic target because of its involvement in the platelet activation processes leading to inflammation. This study aimed to identify potential natural product-derived inhibitory molecules against the p38α MAPK receptor to mitigate the eliciting of pro-inflammatory cytokines using computational techniques. The 3D X-ray structure of the receptor with PDB ID 3ZS5 was energy minimized using GROMACS and used for molecular docking via AutoDock Vina. The molecular docking was validated with an acceptable area under the curve (AUC) of 0.704, which was computed from the receiver operating characteristic (ROC) curve. A compendium of 38,271 natural products originating from Africa and China together with eleven known p38 MAPK inhibitors were screened against the receptor. Four potential lead compounds ZINC1691180, ZINC5519433, ZINC4520996 and ZINC5733756 were identified. The compounds formed strong intermolecular bonds with critical residues Val38, Ala51, Lys53, Thr106, Leu108, Met109 and Phe169. Additionally, they exhibited appreciably low binding energies which were corroborated via molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) calculations. The compounds were also predicted to have plausible pharmacological profiles with insignificant toxicity. The molecules were also predicted to be anti-inflammatory, kinase inhibitors, antiviral, platelet aggregation inhibitors, and immunosuppressive, with probable activity (Pa) greater than probable inactivity (Pi). ZINC5733756 is structurally similar to estradiol with a Tanimoto coefficient value of 0.73, which exhibits anti-inflammatory activity by targeting the activation of Nrf2. Similarly, ZINC1691180 has been reported to elicit anti-inflammatory activity in vitro. The compounds may serve as scaffolds for the design of potential biotherapeutic molecules against the cytokine storm associated with COVID-19.


Subject(s)
COVID-19/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , Animals , Biological Products/metabolism , Coronavirus/pathogenicity , Cytokines/metabolism , Humans , Inflammation/metabolism , Molecular Docking Simulation , ROC Curve
13.
J Med Virol ; 93(2): 1002-1007, 2021 02.
Article in English | MEDLINE | ID: covidwho-1196430

ABSTRACT

Respiratory viral infection can cause severe disease and hospitalization, especially among children, the elderly, and patients with comorbidities. In Brazil, the official surveillance system of severe acute respiratory infection (SARI) investigates influenza A (IAV) and B (IBV) viruses, respiratory syncytial virus (RSV), adenovirus (HAdV), and parainfluenza viruses (hPIV 1-3). In Rio Grande do Sul (RS), Brazil, many fatalities associated with SARI between 2013 and 2017 occurred among patients without underlying diseases and for whom the causative agent had not been identified using official protocols. This cross-sectional study analyzed the presence of coronaviruses (HCoV), bocavirus (HBoV), metapneumovirus (hMPV), and rhinovirus in patients who died of SARI despite not having comorbidities, and that were negative for IAV, IBV, RSV, HAdV, and hPIV. Nasopharyngeal aspirates/swabs from patients were used for nucleic acid extraction. The presence of HCoVs OC43, HKU1, NL63, and 229E; HBoV; hMPV; and rhinovirus was assessed by quantitative reverse transcription-polymerase chain reaction. Clinical data were also analyzed. Between 2013 and 2017, 16 225 cases of SARI were reported in RS; 9.8% of the patients died; 20% of all fatal cases were patients without comorbidities and for whom no pathogen was detected using standard protocols. Analysis of 271 of these cases identified HCoV in nine cases; HBoV, hMPV, and rhinovirus were detected in 3, 3, and 10 cases, respectively. Of note, patients infected with HCoV were adults. Results reinforce the importance of including coronaviruses in diagnostic panels used by official surveillance systems because besides their pandemic potential, endemic HCoVs are associated to severe disease in healthy adults.


Subject(s)
Coronavirus Infections/mortality , Coronavirus Infections/virology , Coronavirus NL63, Human/pathogenicity , Coronavirus OC43, Human/pathogenicity , Adolescent , Adult , Aged , Brazil/epidemiology , Child , Child, Preschool , Common Cold/epidemiology , Common Cold/virology , Coronavirus/classification , Coronavirus/pathogenicity , Cross-Sectional Studies , Female , Healthy Volunteers , Humans , Infant , Male , Middle Aged , Nasopharynx/virology , Respiratory Tract Infections/virology , Rhinovirus/genetics , Severity of Illness Index , Young Adult
14.
Int J Mol Sci ; 22(1)2020 Dec 30.
Article in English | MEDLINE | ID: covidwho-1006614

ABSTRACT

Being opportunistic intracellular pathogens, viruses are dependent on the host for their replication. They hijack host cellular machinery for their replication and survival by targeting crucial cellular physiological pathways, including transcription, translation, immune pathways, and apoptosis. Immediately after translation, the host and viral proteins undergo a process called post-translational modification (PTM). PTMs of proteins involves the attachment of small proteins, carbohydrates/lipids, or chemical groups to the proteins and are crucial for the proteins' functioning. During viral infection, host proteins utilize PTMs to control the virus replication, using strategies like activating immune response pathways, inhibiting viral protein synthesis, and ultimately eliminating the virus from the host. PTM of viral proteins increases solubility, enhances antigenicity and virulence properties. However, RNA viruses are devoid of enzymes capable of introducing PTMs to their proteins. Hence, they utilize the host PTM machinery to promote their survival. Proteins from viruses belonging to the family: Togaviridae, Flaviviridae, Retroviridae, and Coronaviridae such as chikungunya, dengue, zika, HIV, and coronavirus are a few that are well-known to be modified. This review discusses various host and virus-mediated PTMs that play a role in the outcome during the infection.


Subject(s)
Protein Processing, Post-Translational , RNA Virus Infections/enzymology , RNA Virus Infections/virology , RNA Viruses/metabolism , RNA Viruses/pathogenicity , Viral Proteins/metabolism , Acetylation , Chikungunya virus/metabolism , Coronavirus/metabolism , Coronavirus/pathogenicity , Cytopathogenic Effect, Viral , Glycosylation , HIV/metabolism , HIV/pathogenicity , Host Microbial Interactions , Humans , Phosphorylation , RNA Virus Infections/immunology , RNA Virus Infections/metabolism , RNA Viruses/immunology , Ubiquitination , Virus Replication/physiology , Zika Virus/metabolism , Zika Virus/pathogenicity
15.
Methods Mol Biol ; 2203: 241-261, 2020.
Article in English | MEDLINE | ID: covidwho-729911

ABSTRACT

Coronavirus entry encompasses the initial steps of infection, from virion attachment to genome release. Advances in fluorescent labeling of viral and cellular components and confocal imaging enable broad spectrum studies on this process. Here, we describe methods for visualization of coronavirus entry into immortalized cell lines and 3D tissue culture models.


Subject(s)
Coronavirus/pathogenicity , Host-Pathogen Interactions/physiology , Microscopy, Confocal/methods , Cell Line , Coronavirus/isolation & purification , Coronavirus Nucleocapsid Proteins , Culture Media/chemistry , Endocytosis , Humans , Nucleocapsid Proteins/metabolism , Triiodobenzoic Acids/chemistry , Virus Internalization
16.
Methods Mol Biol ; 2203: 223-229, 2020.
Article in English | MEDLINE | ID: covidwho-729909

ABSTRACT

All viruses have to overcome the innate immune response in order to establish infection. Methods have been developed to assay if, and how, viruses overcome these responses, and many can be directly applied to coronaviruses. Here, in vitro methods to determine how coronaviruses overcome this response are described.


Subject(s)
Coronavirus/growth & development , Coronavirus/metabolism , Virus Cultivation/methods , Animals , Cell Line , Coronavirus/pathogenicity , Host-Pathogen Interactions , Humans , Immunity, Innate/immunology , Interferons , Middle East Respiratory Syndrome Coronavirus/growth & development , Middle East Respiratory Syndrome Coronavirus/pathogenicity , RNA, Viral , Viral Nonstructural Proteins , Virus Replication
17.
Methods Mol Biol ; 2203: 205-221, 2020.
Article in English | MEDLINE | ID: covidwho-729908

ABSTRACT

We have developed a screening system using the yeast Saccharomyces cerevisiae to identify eukaryotic genes involved in the replication of mammalian viruses. Yeast come with various advantages, but in the context of coronavirus research and the system outlined here, they are simple and easy to work with and can be used at biosafety level 2. The system involves inducible expression of individual viral proteins and identification of detrimental phenotypes in the yeast. Yeast knockout and overexpression libraries can then be used for genome-wide screening of host proteins that provide a suppressor phenotype. From the yeast hits, a narrowed list of candidate genes can be produced to investigate for roles in viral replication. Since the system only requires expression of viral proteins, it can be used for any current or emerging virus, regardless of biocontainment requirements and ability to culture the virus. In this chapter, we will outline the protocols that can be used to take advantage of S. cerevisiae as a tool to advance understanding of how viruses interact with eukaryotic cells.


Subject(s)
Coronavirus/physiology , Coronavirus/pathogenicity , Host-Pathogen Interactions/physiology , Saccharomyces cerevisiae/genetics , Plasmids , Viral Proteins/genetics , Viral Proteins/isolation & purification , Virus Replication
18.
Methods Mol Biol ; 2203: 187-204, 2020.
Article in English | MEDLINE | ID: covidwho-729907

ABSTRACT

Biotin-based proximity labeling circumvents major pitfalls of classical biochemical approaches to identify protein-protein interactions. It consists of enzyme-catalyzed biotin tags ubiquitously apposed on proteins located in close proximity of the labeling enzyme, followed by affinity purification and identification of biotinylated proteins by mass spectrometry. Here we outline the methods by which the molecular microenvironment of the coronavirus replicase/transcriptase complex (RTC), i.e., proteins located within a close perimeter of the RTC, can be determined by different proximity labeling approaches using BirAR118G (BioID), TurboID, and APEX2. These factors represent a molecular signature of coronavirus RTCs and likely contribute to the viral life cycle, thereby constituting attractive targets for the development of antiviral intervention strategies.


Subject(s)
Coronavirus/pathogenicity , Enzymes/genetics , Host-Pathogen Interactions/physiology , Proteomics/methods , Viral Proteins/metabolism , Animals , Ascorbate Peroxidases/genetics , Biotinylation , Carbon-Nitrogen Ligases/genetics , Cell Line , Coronavirus/genetics , Enzymes/metabolism , Escherichia coli Proteins/genetics , Fluorescent Antibody Technique , Microorganisms, Genetically-Modified , Repressor Proteins/genetics , Viral Proteins/chemistry , Viral Proteins/genetics
19.
Clin Infect Dis ; 71(16): 2139-2149, 2020 11 19.
Article in English | MEDLINE | ID: covidwho-1153181

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is believed to be mostly transmitted by medium- to large-sized respiratory droplets, although airborne transmission may be possible in healthcare settings involving aerosol-generating procedures. Exposure to respiratory droplets can theoretically be reduced by surgical mask usage. However, there is a lack of experimental evidence supporting surgical mask usage for prevention of COVID-19. METHODS: We used a well-established golden Syrian hamster SARS-CoV-2 model. We placed SARS-CoV-2-challenged index hamsters and naive hamsters into closed system units each comprising 2 different cages separated by a polyvinyl chloride air porous partition with unidirectional airflow within the isolator. The effect of a surgical mask partition placed between the cages was investigated. Besides clinical scoring, hamster specimens were tested for viral load, histopathology, and viral nucleocapsid antigen expression. RESULTS: Noncontact transmission was found in 66.7% (10/15) of exposed naive hamsters. Surgical mask partition for challenged index or naive hamsters significantly reduced transmission to 25% (6/24, P = .018). Surgical mask partition for challenged index hamsters significantly reduced transmission to only 16.7% (2/12, P = .019) of exposed naive hamsters. Unlike the severe manifestations of challenged hamsters, infected naive hamsters had lower clinical scores, milder histopathological changes, and lower viral nucleocapsid antigen expression in respiratory tract tissues. CONCLUSIONS: SARS-CoV-2 could be transmitted by respiratory droplets or airborne droplet nuclei which could be reduced by surgical mask partition in the hamster model. This is the first in vivo experimental evidence to support the possible benefit of surgical mask in prevention of COVID-19 transmission, especially when masks were worn by infected individuals.


Subject(s)
COVID-19/transmission , Masks , SARS-CoV-2/pathogenicity , Animals , Coronavirus/pathogenicity , Cricetinae , Female , Male , Pandemics , Viral Load
20.
Clin Infect Dis ; 71(16): 2158-2166, 2020 11 19.
Article in English | MEDLINE | ID: covidwho-1153176

ABSTRACT

BACKGROUND: In December 2019, the coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) broke out in Wuhan. Epidemiological and clinical characteristics of patients with COVID-19 have been reported, but the relationships between laboratory features and viral load has not been comprehensively described. METHODS: Adult inpatients (≥18 years old) with COVID-19 who underwent multiple (≥5 times) nucleic acid tests with nasal and pharyngeal swabs were recruited from Renmin Hospital of Wuhan University, including general patients (n = 70), severe patients (n = 195), and critical patients (n = 43). Laboratory data, demographic data, and clinical data were extracted from electronic medical records. The fitted polynomial curve was used to explore the association between serial viral loads and illness severity. RESULTS: Viral load of SARS-CoV-2 peaked within the first few days (2-4 days) after admission, then decreased rapidly along with virus rebound under treatment. Critical patients had the highest viral loads, in contrast to the general patients showing the lowest viral loads. The viral loads were higher in sputum compared with nasal and pharyngeal swab (P = .026). The positive rate of respiratory tract samples was significantly higher than that of gastrointestinal tract samples (P < .001). The SARS-CoV-2 viral load was negatively correlated with portion parameters of blood routine and lymphocyte subsets and was positively associated with laboratory features of cardiovascular system. CONCLUSIONS: The serial viral loads of patients revealed whole viral shedding during hospitalization and the resurgence of virus during the treatment, which could be used for early warning of illness severity, thus improve antiviral interventions.


Subject(s)
COVID-19/epidemiology , Coronavirus/pathogenicity , China/epidemiology , Female , Humans , Male , Serologic Tests , Viral Load
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