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Dong F, Tacchi L, Xu Z, LaPatra SE, Salinas I. Vaccination Route Determines the Kinetics and Magnitude of Nasal Innate Immune Responses in Rainbow Trout ( Oncorhynchus mykiss). BIOLOGY 2020; 9:biology9100319. [PMID: 33019693 PMCID: PMC7601189 DOI: 10.3390/biology9100319] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 09/08/2020] [Accepted: 09/30/2020] [Indexed: 12/16/2022]
Abstract
Simple Summary Many pathogens exploit the olfactory route to reach critical organs in the body such as the brain or lungs. Thus, effective onset of an early innate immune response in the nasal epithelium is key to stopping pathogen progression. The stimulation of nasal immunity by vaccines may depend on the type of vaccine and vaccination route. The goal of this study was to evaluate the ability of a live attenuated viral vaccine to stimulate innate immunity in the olfactory organ of rainbow trout, a teleost fish of commercial aquaculture value. The kinetics and magnitude of the innate immune response depended on the route of vaccination, with the strongest and fastest responses recorded in intranasally vaccinated fish. Injection vaccination had an intermediate effect, whereas immersion vaccination resulted in delayed and weak nasal innate immunity. Injection vaccination, even with the vehicle control, induced mortality in fingerlings, whereas nasal and immersion vaccines were safe. Challenge experiments with the live virus revealed that nasal and injected vaccines conferred very high and comparable levels of protection, but immersion vaccination only induced transient protection. In conclusion, the route of vaccination determines the type, magnitude and velocity of the innate immune response in the nasal epithelium of animals. Abstract Many pathogens infect animal hosts via the nasal route. Thus, understanding how vaccination stimulates early nasal immune responses is critical for animal and human health. Vaccination is the most effective method to prevent disease outbreaks in farmed fish. Nasal vaccination induces strong innate and adaptive immune responses in rainbow trout and was shown to be highly effective against infectious hematopoietic necrosis (IHN). However, direct comparisons between intranasal, injection and immersion vaccination routes have not been conducted in any fish species. Moreover, whether injection or immersion routes induce nasal innate immune responses is unknown. The goal of this study is to compare the effects of three different vaccine delivery routes, including intranasal (IN), intramuscular (i.m.) injection and immersion (imm) routes on the trout nasal innate immune response. Expression analyses of 13 immune-related genes in trout nasopharynx-associated lymphoid tissue (NALT), detected significant changes in immune expression in all genes analyzed in response to the three vaccination routes. However, nasal vaccination induced the strongest and fastest changes in innate immune gene expression compared to the other two routes. Challenge experiments 7 days post-vaccination (dpv) show the highest survival rates in the IN- and imm-vaccinated groups. However, survival rates in the imm group were significantly lower than the IN- and i.m.-vaccinated groups 28 dpv. Our results confirm that nasal vaccination of rainbow trout with live attenuated IHNV is highly effective and that the protection conferred by immersion vaccination is transient. These results also demonstrate for the first time that immersion vaccines stimulate NALT immune responses in salmonids.
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Affiliation(s)
- Fen Dong
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA; (F.D.); (L.T.)
| | - Luca Tacchi
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA; (F.D.); (L.T.)
| | - Zhen Xu
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China;
| | | | - Irene Salinas
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA; (F.D.); (L.T.)
- Correspondence:
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102
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Hou YJ, Chiba S, Halfmann P, Ehre C, Kuroda M, Dinnon KH, Leist SR, Schäfer A, Nakajima N, Takahashi K, Lee RE, Mascenik TM, Edwards CE, Tse LV, Boucher RC, Randell SH, Suzuki T, Gralinski LE, Kawaoka Y, Baric RS. SARS-CoV-2 D614G Variant Exhibits Enhanced Replication ex vivo and Earlier Transmission in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.09.28.317685. [PMID: 33024969 PMCID: PMC7536872 DOI: 10.1101/2020.09.28.317685] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The D614G substitution in the S protein is most prevalent SARS-CoV-2 strain circulating globally, but its effects in viral pathogenesis and transmission remain unclear. We engineered SARS-CoV-2 variants harboring the D614G substitution with or without nanoluciferase. The D614G variant replicates more efficiency in primary human proximal airway epithelial cells and is more fit than wildtype (WT) virus in competition studies. With similar morphology to the WT virion, the D614G virus is also more sensitive to SARS-CoV-2 neutralizing antibodies. Infection of human ACE2 transgenic mice and Syrian hamsters with the WT or D614G viruses produced similar titers in respiratory tissue and pulmonary disease. However, the D614G variant exhibited significantly faster droplet transmission between hamsters than the WT virus, early after infection. Our study demonstrated the SARS-CoV2 D614G substitution enhances infectivity, replication fitness, and early transmission.
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Affiliation(s)
- Yixuan J. Hou
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Shiho Chiba
- Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
| | - Peter Halfmann
- Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
| | - Camille Ehre
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Makoto Kuroda
- Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
| | - Kenneth H Dinnon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sarah R. Leist
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Alexandra Schäfer
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Noriko Nakajima
- Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kenta Takahashi
- Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Rhianna E. Lee
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Teresa M. Mascenik
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Caitlin E. Edwards
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Longping V. Tse
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Richard C. Boucher
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Scott H. Randell
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Tadaki Suzuki
- Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Lisa E. Gralinski
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yoshihiro Kawaoka
- Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
| | - Ralph S. Baric
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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103
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Wu Z, Harrich D, Li Z, Hu D, Li D. The unique features of SARS-CoV-2 transmission: Comparison with SARS-CoV, MERS-CoV and 2009 H1N1 pandemic influenza virus. Rev Med Virol 2020; 31:e2171. [PMID: 33350025 PMCID: PMC7537046 DOI: 10.1002/rmv.2171] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/01/2020] [Accepted: 09/03/2020] [Indexed: 01/10/2023]
Abstract
From 2002 to 2019, three deadly human coronaviruses (hCoVs), severe acute respiratory syndrome coronavirus (SARS‐CoV), Middle Eastern respiratory syndrome coronavirus (MERS‐CoV) and severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) emerged to produce outbreaks of SARS, MERS and coronavirus disease 2019 (Covid‐19), respectively. All three hCoVs are members of the Betacoronavirus genus in the subfamily Orthocoronavirinae and share many similarities in virology and epidemiology. However, the pattern and scale of Covid‐19 global spread is similar to 2009 pandemic H1N1 influenza (H1N1pdm09), rather than SARS or MERS. Covid‐19 exhibits high viral shedding in the upper respiratory tract at an early stage of infection, and has a high proportion of transmission competent individuals that are pre‐symptomatic, asymptomatic and mildly symptomatic, characteristics seen in H1N1pdm09 but not in SARS or MERS. These two traits of Covid‐19 and H1N1pdm09 result in reduced efficiency in identification of transmission sources by symptomatic screening and play important roles in their ability to spread unchecked to cause pandemics. To overcome these attributes of Covid‐19 in community transmission, identifying the transmission source by testing for virus shedding and interrupting chains of transmission by social distancing and public masking are required.
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Affiliation(s)
- Zhonglan Wu
- Ningxia Center for Disease Control and Prevention, Yinchuan, Ningxia, China.,College of Public Health, Ningxia Medical University, Yinchuan, Ningxia, China
| | - David Harrich
- Department of Cell and Molecular Biology, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Zhongyang Li
- Eastern Health Library Service Maroondah Hospital, Box Hill, Victoria, Australia
| | - Dongsheng Hu
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, China
| | - Dongsheng Li
- Department of Cell and Molecular Biology, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
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104
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Shi PY, Plante J, Liu Y, Liu J, Xia H, Johnson B, Lokugamage K, Zhang X, Muruato A, Zou J, Fontes-Garfias C, Mirchandani D, Scharton D, Kalveram B, Bilello J, Ku Z, An Z, Freiberg A, Menachery V, Xie X, Plante K, Weaver S. Spike mutation D614G alters SARS-CoV-2 fitness and neutralization susceptibility. RESEARCH SQUARE 2020:rs.3.rs-70482. [PMID: 32935091 PMCID: PMC7491579 DOI: 10.21203/rs.3.rs-70482/v1] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A spike protein mutation D614G became dominant in SARS-CoV-2 during the COVID-19 pandemic. However, the mutational impact on viral spread and vaccine efficacy remains to be defined. Here we engineer the D614G mutation in the SARS-CoV-2 USA-WA1/2020 strain and characterize its effect on viral replication, pathogenesis, and antibody neutralization. The D614G mutation significantly enhances SARS-CoV-2 replication on human lung epithelial cells and primary human airway tissues, through an improved infectivity of virions with the spike receptor-binding domain in an "up" conformation for binding to ACE2 receptor. Hamsters infected with D614 or G614 variants developed similar levels of weight loss. However, the G614 virus produced higher infectious titers in the nasal washes and trachea, but not lungs, than the D614 virus. The hamster results confirm clinical evidence that the D614G mutation enhances viral loads in the upper respiratory tract of COVID-19 patients and may increases transmission. For antibody neutralization, sera from D614 virus-infected hamsters consistently exhibit higher neutralization titers against G614 virus than those against D614 virus, indicating that (i) the mutation may not reduce the ability of vaccines in clinical trials to protect against COVID-19 and (ii) therapeutic antibodies should be tested against the circulating G614 virus before clinical development.
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Affiliation(s)
- Pei-Yong Shi
- The University of Texas Medical Branch at Galveston
| | | | - Yang Liu
- University of Texas Medical Branch
| | | | | | | | | | | | | | | | | | | | | | | | | | - Zhiqiang Ku
- The University of Texas Health Science Center at Houston
| | - Zhiqiang An
- University of Texas Health Science Center at Houston
| | | | | | | | | | - Scott Weaver
- The University of Texas Medical Branch at Galveston
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105
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Plante JA, Liu Y, Liu J, Xia H, Johnson BA, Lokugamage KG, Zhang X, Muruato AE, Zou J, Fontes-Garfias CR, Mirchandani D, Scharton D, Bilello JP, Ku Z, An Z, Kalveram B, Freiberg AN, Menachery VD, Xie X, Plante KS, Weaver SC, Shi PY. Spike mutation D614G alters SARS-CoV-2 fitness and neutralization susceptibility. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.09.01.278689. [PMID: 32908978 PMCID: PMC7480025 DOI: 10.1101/2020.09.01.278689] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A spike protein mutation D614G became dominant in SARS-CoV-2 during the COVID-19 pandemic. However, the mutational impact on viral spread and vaccine efficacy remains to be defined. Here we engineer the D614G mutation in the SARS-CoV-2 USA-WA1/2020 strain and characterize its effect on viral replication, pathogenesis, and antibody neutralization. The D614G mutation significantly enhances SARS-CoV-2 replication on human lung epithelial cells and primary human airway tissues, through an improved infectivity of virions with the spike receptor-binding domain in an "up" conformation for binding to ACE2 receptor. Hamsters infected with D614 or G614 variants developed similar levels of weight loss. However, the G614 virus produced higher infectious titers in the nasal washes and trachea, but not lungs, than the D614 virus. The hamster results confirm clinical evidence that the D614G mutation enhances viral loads in the upper respiratory tract of COVID-19 patients and may increases transmission. For antibody neutralization, sera from D614 virus-infected hamsters consistently exhibit higher neutralization titers against G614 virus than those against D614 virus, indicating that (i) the mutation may not reduce the ability of vaccines in clinical trials to protect against COVID-19 and (ii) therapeutic antibodies should be tested against the circulating G614 virus before clinical development.
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Affiliation(s)
- Jessica A. Plante
- World Reference Center for Emerging Viruses and Arboviruses, University of Texas Medical Branch, Galveston TX, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston TX, USA
| | - Yang Liu
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston TX, USA
| | - Jianying Liu
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston TX, USA
| | - Hongjie Xia
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston TX, USA
| | - Bryan A. Johnson
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX, USA
| | - Kumari G. Lokugamage
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston TX, USA
| | - Xianwen Zhang
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston TX, USA
| | - Antonio E. Muruato
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston TX, USA
| | - Jing Zou
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston TX, USA
| | - Camila R. Fontes-Garfias
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston TX, USA
| | - Divya Mirchandani
- World Reference Center for Emerging Viruses and Arboviruses, University of Texas Medical Branch, Galveston TX, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston TX, USA
| | - Dionna Scharton
- World Reference Center for Emerging Viruses and Arboviruses, University of Texas Medical Branch, Galveston TX, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston TX, USA
| | | | - Zhiqiang Ku
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, USA
| | - Zhiqiang An
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, USA
| | - Birte Kalveram
- Department of Pathology, University of Texas Medical Branch, Galveston TX, USA
| | - Alexander N. Freiberg
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX, USA
- Department of Pathology, University of Texas Medical Branch, Galveston TX, USA
- Center for Biodefense & Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Vineet D. Menachery
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston TX, USA
| | - Xuping Xie
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston TX, USA
| | - Kenneth S. Plante
- World Reference Center for Emerging Viruses and Arboviruses, University of Texas Medical Branch, Galveston TX, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston TX, USA
| | - Scott C. Weaver
- World Reference Center for Emerging Viruses and Arboviruses, University of Texas Medical Branch, Galveston TX, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston TX, USA
- Institute for Translational Sciences, University of Texas Medical Branch, Galveston, TX, USA
- Center for Biodefense & Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Pei-Yong Shi
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston TX, USA
- Institute for Translational Sciences, University of Texas Medical Branch, Galveston, TX, USA
- Center for Biodefense & Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
- Lead Contact
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106
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Das SK, Alam JE, Plumari S, Greco V. Transmission of airborne virus through sneezed and coughed droplets. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2020; 32:097102. [PMID: 32982136 PMCID: PMC7513825 DOI: 10.1063/5.0022859] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 08/15/2020] [Indexed: 05/18/2023]
Abstract
The spread of COVID19 through droplets ejected by infected individuals during sneezing and coughing has been considered a matter of key concern. Therefore, a quantitative understanding of the propagation of droplets containing the virus assumes immense importance. Here, we investigate the evolution of droplets in space and time under varying external conditions of temperature, humidity, and wind flow by using laws of statistical and fluid mechanics. The effects of drag, diffusion, and gravity on droplets of different sizes and ejection velocities have been considered during their motion in air. In still air, we found that bigger droplets traverse a larger distance, but smaller droplets remain suspended in air for a longer time. Therefore, in still air, the horizontal distance that a healthy individual should maintain from an infected one is based on the bigger droplets, but the time interval to be maintained is based on the smaller droplets. We show that in places with wind flow, the lighter droplets travel a larger distance and remain suspended in air for a longer time. Therefore, we conclude that both temporal and geometric distance that a healthy individual should maintain from an infected one is based on the smaller droplets under flowing air, which makes the use of a mask mandatory to prevent the virus. Maintenance of only stationary separation between healthy and infected individuals is not substantiated. The quantitative results obtained here will be useful to devise strategies for preventing the spread of other types of droplets containing microorganisms.
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Affiliation(s)
- Santosh K. Das
- School of Physical Sciences, Indian Institute of
Technology Goa, Ponda 403401, Goa, India
| | - Jan-e Alam
- Variable Energy Cyclotron Centre,
1/AF Bidhan Nagar, Kolkata 700064, India and Homi Bhabha
National Institute, Training School Complex, Mumbai 400085,
India
| | - Salvatore Plumari
- Department of Physics and Astronomy, University of
Catania, Via S. Sofia 64, I-95125 Catania, Italy and
Laboratori Nazionali del Sud, INFN-LNS, Via S. Sofia 62,
I-95123 Catania, Italy
| | - Vincenzo Greco
- Department of Physics and Astronomy, University of
Catania, Via S. Sofia 64, I-95125 Catania, Italy and
Laboratori Nazionali del Sud, INFN-LNS, Via S. Sofia 62,
I-95123 Catania, Italy
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107
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Abstract
Influenza A virus (IAV) is a major pathogen of the human respiratory tract, where the virus coexists and interacts with bacterial populations comprising the respiratory tract microbiome. Synergies between IAV and respiratory bacterial pathogens promote enhanced inflammation and disease burden that exacerbate morbidity and mortality. We demonstrate that direct interactions between IAV and encapsulated bacteria commonly found in the respiratory tract promote environmental stability and infectivity of IAV. Antibiotic-mediated depletion of the respiratory bacterial flora abrogated IAV transmission in ferret models, indicating that these virus-bacterium interactions are operative for airborne transmission of IAV. Restoring IAV airborne transmission in antibiotic-treated ferrets by coinfection with Streptococcus pneumoniae confirmed a role for specific members of the bacterial respiratory community in promoting IAV transmission. These results implicate a role for the bacterial respiratory flora in promoting airborne transmission of IAV.IMPORTANCE Infection with influenza A virus (IAV), especially when complicated with a secondary bacterial infection, is a leading cause of global mortality and morbidity. Gaining a greater understanding of the transmission dynamics of IAV is important during seasonal IAV epidemics and in the event of a pandemic. Direct bacterium-virus interactions are a recently appreciated aspect of infectious disease biology. Direct interactions between IAV and specific bacterial species of the human upper respiratory tract were found to promote the stability and infectivity of IAV during desiccation stress. Viral environmental stability is an important aspect during transmission, suggesting a potential role for bacterial respiratory communities in IAV transmission. Airborne transmission of IAV was abrogated upon depletion of nasal bacterial flora with topical antibiotics. This defect could be functionally complemented by S. pneumoniae coinfection. These data suggest that bacterial coinfection may be an underappreciated aspect of IAV transmission dynamics.
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108
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Dbouk T, Drikakis D. Weather impact on airborne coronavirus survival. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2020; 32:093312. [PMID: 32982135 PMCID: PMC7513827 DOI: 10.1063/5.0024272] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 08/19/2020] [Indexed: 05/03/2023]
Abstract
The contribution of this paper toward understanding of airborne coronavirus survival is twofold: We develop new theoretical correlations for the unsteady evaporation of coronavirus (CoV) contaminated saliva droplets. Furthermore, we implement the new correlations in a three-dimensional multiphase Eulerian-Lagrangian computational fluid dynamics solver to study the effects of weather conditions on airborne virus transmission. The new theory introduces a thermal history kernel and provides transient Nusselt (Nu) and Sherwood (Sh) numbers as a function of the Reynolds (Re), Prandtl (Pr), and Schmidt numbers (Sc). For the first time, these new correlations take into account the mixture properties due to the concentration of CoV particles in a saliva droplet. We show that the steady-state relationships induce significant errors and must not be applied in unsteady saliva droplet evaporation. The classical theory introduces substantial deviations in Nu and Sh values when increasing the Reynolds number defined at the droplet scale. The effects of relative humidity, temperature, and wind speed on the transport and viability of CoV in a cloud of airborne saliva droplets are also examined. The results reveal that a significant reduction of virus viability occurs when both high temperature and low relative humidity occur. The droplet cloud's traveled distance and concentration remain significant at any temperature if the relative humidity is high, which is in contradiction with what was previously believed by many epidemiologists. The above could explain the increase in CoV cases in many crowded cities around the middle of July (e.g., Delhi), where both high temperature and high relative humidity values were recorded one month earlier (during June). Moreover, it creates a crucial alert for the possibility of a second wave of the pandemic in the coming autumn and winter seasons when low temperatures and high wind speeds will increase airborne virus survival and transmission.
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109
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Pendar MR, Páscoa JC. Numerical modeling of the distribution of virus carrying saliva droplets during sneeze and cough. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2020; 32:083305. [PMID: 35002198 PMCID: PMC8726427 DOI: 10.1063/5.0018432] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 07/14/2020] [Indexed: 05/18/2023]
Abstract
Violent respiratory diseases, i.e., coronavirus (COVID-19), spread through saliva in coughs and sneezes or are even exhaled in the form of microbial pathogen micro-droplets. Therefore, in this work, a comprehensive fully coupled Eulerian-Lagrangian method has been applied for infection control, thus leading to a deeper understanding of the saliva-disease-carrier droplet transmission mechanisms and also of their trajectory tracking by using the OpenFOAM package. This model determines the droplet-air interactions, the breakup process, and turbulent dispersion forces on each micro-droplet that is expelled within the respiratory tract in a correct way. By examining a broad range of initial velocities, size distributions, injection angles of saliva micro-droplets, and mouth opening areas, we predict the maximum opening area that can be driven by micro-droplets. One important contribution of this work is to present a correlation for the length and width of the overall direct maximum reach of the micro-droplets, driven by a wide range of mild coughs to intense sneezes. Our results indicate that the movement of the expelled droplets is mainly influenced by their size, angle, velocity, and environmental factors. During a virus crisis, like COVID-19, this paper can be used to determine the "social distance" between individuals to avoid contamination, by inhaling or touching their bodies, due to these saliva-disease-carrier droplets in sneezing, at various social distance positions such as face-to-face, meeting standing, and near equipment. The safe distance must be increased to around 4 m during a sneeze. By wearing a face mask and by bending the head during a sneeze as a protective action, we can reduce the contamination area to one-third and three-quarters, respectively. Furthermore, the dispersion of the film of the expelled saliva micro-droplets and the spatial relationship between the subjects, which affects the airflow inside the room, are also analyzed in detail.
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Affiliation(s)
- Mohammad-Reza Pendar
- Department of Electromechanical Engineering, C-MAST (Center for Mechanical
and Aerospace Sciences and Technologies), University of Beira Interior,
Covilhã, Castelo Branco 6201-001, Portugal
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110
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Hou YJ, Okuda K, Edwards CE, Martinez DR, Asakura T, Dinnon KH, Kato T, Lee RE, Yount BL, Mascenik TM, Chen G, Olivier KN, Ghio A, Tse LV, Leist SR, Gralinski LE, Schäfer A, Dang H, Gilmore R, Nakano S, Sun L, Fulcher ML, Livraghi-Butrico A, Nicely NI, Cameron M, Cameron C, Kelvin DJ, de Silva A, Margolis DM, Markmann A, Bartelt L, Zumwalt R, Martinez FJ, Salvatore SP, Borczuk A, Tata PR, Sontake V, Kimple A, Jaspers I, O'Neal WK, Randell SH, Boucher RC, Baric RS. SARS-CoV-2 Reverse Genetics Reveals a Variable Infection Gradient in the Respiratory Tract. Cell 2020; 182:429-446.e14. [PMID: 32526206 DOI: 10.1016/j.cell.2020.05] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/11/2020] [Accepted: 05/20/2020] [Indexed: 05/26/2023]
Abstract
The mode of acquisition and causes for the variable clinical spectrum of coronavirus disease 2019 (COVID-19) remain unknown. We utilized a reverse genetics system to generate a GFP reporter virus to explore severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogenesis and a luciferase reporter virus to demonstrate sera collected from SARS and COVID-19 patients exhibited limited cross-CoV neutralization. High-sensitivity RNA in situ mapping revealed the highest angiotensin-converting enzyme 2 (ACE2) expression in the nose with decreasing expression throughout the lower respiratory tract, paralleled by a striking gradient of SARS-CoV-2 infection in proximal (high) versus distal (low) pulmonary epithelial cultures. COVID-19 autopsied lung studies identified focal disease and, congruent with culture data, SARS-CoV-2-infected ciliated and type 2 pneumocyte cells in airway and alveolar regions, respectively. These findings highlight the nasal susceptibility to SARS-CoV-2 with likely subsequent aspiration-mediated virus seeding to the lung in SARS-CoV-2 pathogenesis. These reagents provide a foundation for investigations into virus-host interactions in protective immunity, host susceptibility, and virus pathogenesis.
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Affiliation(s)
- Yixuan J Hou
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kenichi Okuda
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Caitlin E Edwards
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - David R Martinez
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Takanori Asakura
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kenneth H Dinnon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Takafumi Kato
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Rhianna E Lee
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Boyd L Yount
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Teresa M Mascenik
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Gang Chen
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kenneth N Olivier
- Laboratory of Chronic Airway Infection, Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Andrew Ghio
- National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Chapel Hill, NC, USA
| | - Longping V Tse
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sarah R Leist
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Lisa E Gralinski
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Alexandra Schäfer
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Hong Dang
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Rodney Gilmore
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Satoko Nakano
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ling Sun
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - M Leslie Fulcher
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Nathan I Nicely
- Protein Expression and Purification Core, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mark Cameron
- Department of Population and Quantitative Health Science, Case Western Reserve University, Cleveland, OH, USA
| | - Cheryl Cameron
- Department of Nutrition, Case Western Reserve University, Cleveland, OH, USA
| | - David J Kelvin
- Department of Microbiology and Immunology, Canadian Center for Vaccinology, Dalhousie University, Halifax, NS, Canada; Laboratory of Immunology, Shantou University Medical College, Shantou, Guangdong, China
| | - Aravinda de Silva
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - David M Margolis
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; HIV Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Alena Markmann
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Luther Bartelt
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ross Zumwalt
- Department of Pathology, University of New Mexico, Albuquerque, NM, USA
| | - Fernando J Martinez
- Division of Pulmonary and Critical Care Medicine, Joan & Sanford I. Weill Medical College of Cornell University, New York, NY, USA
| | - Steven P Salvatore
- Department of Pathology, Joan & Sanford I. Weill Medical College of Cornell University, New York, NY, USA
| | - Alain Borczuk
- Department of Pathology, Joan & Sanford I. Weill Medical College of Cornell University, New York, NY, USA
| | - Purushothama R Tata
- Department of Cell Biology, Regeneration Next Initiative, Duke University Medical Center, Durham, NC, USA
| | - Vishwaraj Sontake
- Department of Cell Biology, Regeneration Next Initiative, Duke University Medical Center, Durham, NC, USA
| | - Adam Kimple
- Department of Otolaryngology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ilona Jaspers
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Wanda K O'Neal
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Scott H Randell
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Richard C Boucher
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Ralph S Baric
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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111
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Hou YJ, Okuda K, Edwards CE, Martinez DR, Asakura T, Dinnon KH, Kato T, Lee RE, Yount BL, Mascenik TM, Chen G, Olivier KN, Ghio A, Tse LV, Leist SR, Gralinski LE, Schäfer A, Dang H, Gilmore R, Nakano S, Sun L, Fulcher ML, Livraghi-Butrico A, Nicely NI, Cameron M, Cameron C, Kelvin DJ, de Silva A, Margolis DM, Markmann A, Bartelt L, Zumwalt R, Martinez FJ, Salvatore SP, Borczuk A, Tata PR, Sontake V, Kimple A, Jaspers I, O'Neal WK, Randell SH, Boucher RC, Baric RS. SARS-CoV-2 Reverse Genetics Reveals a Variable Infection Gradient in the Respiratory Tract. Cell 2020; 182:429-446.e14. [PMID: 32526206 PMCID: PMC7250779 DOI: 10.1016/j.cell.2020.05.042] [Citation(s) in RCA: 1145] [Impact Index Per Article: 229.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/11/2020] [Accepted: 05/20/2020] [Indexed: 02/06/2023]
Abstract
The mode of acquisition and causes for the variable clinical spectrum of coronavirus disease 2019 (COVID-19) remain unknown. We utilized a reverse genetics system to generate a GFP reporter virus to explore severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogenesis and a luciferase reporter virus to demonstrate sera collected from SARS and COVID-19 patients exhibited limited cross-CoV neutralization. High-sensitivity RNA in situ mapping revealed the highest angiotensin-converting enzyme 2 (ACE2) expression in the nose with decreasing expression throughout the lower respiratory tract, paralleled by a striking gradient of SARS-CoV-2 infection in proximal (high) versus distal (low) pulmonary epithelial cultures. COVID-19 autopsied lung studies identified focal disease and, congruent with culture data, SARS-CoV-2-infected ciliated and type 2 pneumocyte cells in airway and alveolar regions, respectively. These findings highlight the nasal susceptibility to SARS-CoV-2 with likely subsequent aspiration-mediated virus seeding to the lung in SARS-CoV-2 pathogenesis. These reagents provide a foundation for investigations into virus-host interactions in protective immunity, host susceptibility, and virus pathogenesis.
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Affiliation(s)
- Yixuan J Hou
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kenichi Okuda
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Caitlin E Edwards
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - David R Martinez
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Takanori Asakura
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kenneth H Dinnon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Takafumi Kato
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Rhianna E Lee
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Boyd L Yount
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Teresa M Mascenik
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Gang Chen
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kenneth N Olivier
- Laboratory of Chronic Airway Infection, Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Andrew Ghio
- National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Chapel Hill, NC, USA
| | - Longping V Tse
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sarah R Leist
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Lisa E Gralinski
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Alexandra Schäfer
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Hong Dang
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Rodney Gilmore
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Satoko Nakano
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ling Sun
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - M Leslie Fulcher
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Nathan I Nicely
- Protein Expression and Purification Core, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mark Cameron
- Department of Population and Quantitative Health Science, Case Western Reserve University, Cleveland, OH, USA
| | - Cheryl Cameron
- Department of Nutrition, Case Western Reserve University, Cleveland, OH, USA
| | - David J Kelvin
- Department of Microbiology and Immunology, Canadian Center for Vaccinology, Dalhousie University, Halifax, NS, Canada; Laboratory of Immunology, Shantou University Medical College, Shantou, Guangdong, China
| | - Aravinda de Silva
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - David M Margolis
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; HIV Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Alena Markmann
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Luther Bartelt
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ross Zumwalt
- Department of Pathology, University of New Mexico, Albuquerque, NM, USA
| | - Fernando J Martinez
- Division of Pulmonary and Critical Care Medicine, Joan & Sanford I. Weill Medical College of Cornell University, New York, NY, USA
| | - Steven P Salvatore
- Department of Pathology, Joan & Sanford I. Weill Medical College of Cornell University, New York, NY, USA
| | - Alain Borczuk
- Department of Pathology, Joan & Sanford I. Weill Medical College of Cornell University, New York, NY, USA
| | - Purushothama R Tata
- Department of Cell Biology, Regeneration Next Initiative, Duke University Medical Center, Durham, NC, USA
| | - Vishwaraj Sontake
- Department of Cell Biology, Regeneration Next Initiative, Duke University Medical Center, Durham, NC, USA
| | - Adam Kimple
- Department of Otolaryngology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ilona Jaspers
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Wanda K O'Neal
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Scott H Randell
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Richard C Boucher
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Ralph S Baric
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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112
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Schönrich G, Raftery MJ, Samstag Y. Devilishly radical NETwork in COVID-19: Oxidative stress, neutrophil extracellular traps (NETs), and T cell suppression. Adv Biol Regul 2020; 77:100741. [PMID: 32773102 PMCID: PMC7334659 DOI: 10.1016/j.jbior.2020.100741] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 06/29/2020] [Indexed: 02/06/2023]
Abstract
Pandemic coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and poses an unprecedented challenge to healthcare systems due to the lack of a vaccine and specific treatment options. Accordingly, there is an urgent need to understand precisely the pathogenic mechanisms underlying this multifaceted disease. There is increasing evidence that the immune system reacts insufficiently to SARS-CoV-2 and thus contributes to organ damage and to lethality. In this review, we suggest that the overwhelming production of reactive oxygen species (ROS) resulting in oxidative stress is a major cause of local or systemic tissue damage that leads to severe COVID-19. It increases the formation of neutrophil extracellular traps (NETs) and suppresses the adaptive arm of the immune system, i.e. T cells that are necessary to kill virus-infected cells. This creates a vicious cycle that prevents a specific immune response against SARS-CoV-2. The key role of oxidative stress in the pathogenesis of severe COVID-19 implies that therapeutic counterbalancing of ROS by antioxidants such as vitamin C or NAC and/or by antagonizing ROS production by cells of the mononuclear phagocyte system (MPS) and neutrophil granulocytes and/or by blocking of TNF-α can prevent COVID-19 from becoming severe. Controlled clinical trials and preclinical models of COVID-19 are needed to evaluate this hypothesis.
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Affiliation(s)
- Günther Schönrich
- Institute of Virology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany.
| | - Martin J Raftery
- Institute of Virology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Yvonne Samstag
- Section Molecular Immunology, Institute of Immunology, Heidelberg University Hospital, Heidelberg, Germany.
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113
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Dbouk T, Drikakis D. On respiratory droplets and face masks. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2020; 32:063303. [PMID: 32574231 PMCID: PMC7301882 DOI: 10.1063/5.0015044] [Citation(s) in RCA: 189] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 05/27/2020] [Indexed: 05/02/2023]
Abstract
Face mask filters-textile, surgical, or respiratory-are widely used in an effort to limit the spread of airborne viral infections. Our understanding of the droplet dynamics around a face mask filter, including the droplet containment and leakage from and passing through the cover, is incomplete. We present a fluid dynamics study of the transmission of respiratory droplets through and around a face mask filter. By employing multiphase computational fluid dynamics in a fully coupled Eulerian-Lagrangian framework, we investigate the droplet dynamics induced by a mild coughing incident and examine the fluid dynamics phenomena affecting the mask efficiency. The model takes into account turbulent dispersion forces, droplet phase-change, evaporation, and breakup in addition to the droplet-droplet and droplet-air interactions. The model mimics real events by using data, which closely resemble cough experiments. The study shows that the criteria employed for assessing the face mask performance must be modified to take into account the penetration dynamics of airborne droplet transmission, the fluid dynamics leakage around the filter, and reduction of efficiency during cough cycles. A new criterion for calculating more accurately the mask efficiency by taking into account the penetration dynamics is proposed. We show that the use of masks will reduce the airborne droplet transmission and will also protect the wearer from the droplets expelled from other subjects. However, many droplets still spread around and away from the cover, cumulatively, during cough cycles. Therefore, the use of a mask does not provide complete protection, and social distancing remains important during a pandemic. The implications of the reduced mask efficiency and respiratory droplet transmission away from the mask are even more critical for healthcare workers. The results of this study provide evidence of droplet transmission prevention by face masks, which can guide their use and further improvement.
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114
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Rockx B, Kuiken T, Herfst S, Bestebroer T, Lamers MM, Oude Munnink BB, de Meulder D, van Amerongen G, van den Brand J, Okba NMA, Schipper D, van Run P, Leijten L, Sikkema R, Verschoor E, Verstrepen B, Bogers W, Langermans J, Drosten C, Fentener van Vlissingen M, Fouchier R, de Swart R, Koopmans M, Haagmans BL. Comparative pathogenesis of COVID-19, MERS, and SARS in a nonhuman primate model. Science 2020; 368:1012-1015. [PMID: 32303590 PMCID: PMC7164679 DOI: 10.1126/science.abb7314] [Citation(s) in RCA: 702] [Impact Index Per Article: 140.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 04/15/2020] [Indexed: 11/09/2022]
Abstract
The current pandemic coronavirus, severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), was recently identified in patients with an acute respiratory syndrome, coronavirus disease 2019 (COVID-19). To compare its pathogenesis with that of previously emerging coronaviruses, we inoculated cynomolgus macaques with SARS-CoV-2 or Middle East respiratory syndrome (MERS)-CoV and compared the pathology and virology with historical reports of SARS-CoV infections. In SARS-CoV-2-infected macaques, virus was excreted from nose and throat in the absence of clinical signs and detected in type I and II pneumocytes in foci of diffuse alveolar damage and in ciliated epithelial cells of nasal, bronchial, and bronchiolar mucosae. In SARS-CoV infection, lung lesions were typically more severe, whereas they were milder in MERS-CoV infection, where virus was detected mainly in type II pneumocytes. These data show that SARS-CoV-2 causes COVID-19-like disease in macaques and provides a new model to test preventive and therapeutic strategies.
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Affiliation(s)
- Barry Rockx
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands.
| | - Thijs Kuiken
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Sander Herfst
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Theo Bestebroer
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Mart M Lamers
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Bas B Oude Munnink
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Dennis de Meulder
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | | | - Judith van den Brand
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Nisreen M A Okba
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Debby Schipper
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Peter van Run
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Lonneke Leijten
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Reina Sikkema
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Ernst Verschoor
- Department of Virology, Biomedical Primate Research Centre, Rijswijk, Netherlands
| | - Babs Verstrepen
- Department of Virology, Biomedical Primate Research Centre, Rijswijk, Netherlands
| | - Willy Bogers
- Department of Virology, Biomedical Primate Research Centre, Rijswijk, Netherlands
| | - Jan Langermans
- Animal Science Department, Biomedical Primate Research Centre, Rijswijk, Netherlands
- Population Health Sciences, Unit Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Netherlands
| | | | | | - Ron Fouchier
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Rik de Swart
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Marion Koopmans
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Bart L Haagmans
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, Netherlands.
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115
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Dbouk T, Drikakis D. On coughing and airborne droplet transmission to humans. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2020; 32:053310. [PMID: 32574229 PMCID: PMC7239332 DOI: 10.1063/5.0011960] [Citation(s) in RCA: 271] [Impact Index Per Article: 54.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Our understanding of the mechanisms of airborne transmission of viruses is incomplete. This paper employs computational multiphase fluid dynamics and heat transfer to investigate transport, dispersion, and evaporation of saliva particles arising from a human cough. An ejection process of saliva droplets in air was applied to mimic the real event of a human cough. We employ an advanced three-dimensional model based on fully coupled Eulerian-Lagrangian techniques that take into account the relative humidity, turbulent dispersion forces, droplet phase-change, evaporation, and breakup in addition to the droplet-droplet and droplet-air interactions. We computationally investigate the effect of wind speed on social distancing. For a mild human cough in air at 20 °C and 50% relative humidity, we found that human saliva-disease-carrier droplets may travel up to unexpected considerable distances depending on the wind speed. When the wind speed was approximately zero, the saliva droplets did not travel 2 m, which is within the social distancing recommendations. However, at wind speeds varying from 4 km/h to 15 km/h, we found that the saliva droplets can travel up to 6 m with a decrease in the concentration and liquid droplet size in the wind direction. Our findings imply that considering the environmental conditions, the 2 m social distance may not be sufficient. Further research is required to quantify the influence of parameters such as the environment's relative humidity and temperature among others.
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