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1.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-332137

ABSTRACT

The novel coronavirus (COVID-19 or 2019-nCoV) is a respiratory virus that can exist in the mouth and saliva of patients and spreads through aerosol dispersion. Therefore, stomatological hospitals and departments have become high-infection-risk environments. Accordingly, the search for oral disinfectants that can effectively inactivate the virus has become a highly active area of research. Hexadecyl pyridinium chloride, povidone-iodine, and other common oral disinfectants are the natural primary choices for stomatological hospitals. Therefore, this study investigated the inhibitory effect of hexadecyl pyridinium chloride on SARS-CoV-2 in vitro . Vero cells infected with SARS-CoV-2 were used to determine disinfection effect;the CCK-8 method was used to determine cytotoxicity;and viral load was determined by real-time PCR. The results showed that hexadecyl pyridinium chloride has no obvious cytotoxic effect on Vero cells in the concentration range 0.0125–0.05 mg/mL. The in vitro experiments showed that hexadecyl pyridinium chloride significantly inhibits the virus at concentrations of 0.1 mg/mL or above at 2 min of action. Thus, the results provide experimental support for the use of hexadecyl pyridinium chloride in stomatological hospitals.

2.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-308208

ABSTRACT

The novel coronavirus (COVID-19 or 2019-nCoV) is a respiratory virus that can exist in the mouth and saliva of patients and spreads through aerosol dispersion. In the face of such a serious epidemic, the World Health Organization (who) recommends that governments and individuals take necessary infection control measures. The novel coronavirus (severe acute respiratory syndrome coronavirus;SARS-CoV-2) spread rapidly, causing varying degrees of respiratory disease and, in severe cases. SARS-CoV-2 is a respiratory disease that can be transmitted through direct transmission, aerosol transmission, or contact. Therefore, stomatological hospitals and departments have become high-infection-risk environments. Accordingly, oral disinfectants that can effectively inactivate the virus have become a highly active area of research. Hexadecyl pyridinium chloride, povidone-iodine, and other common oral disinfectants are the natural primary choices for stomatological hospitals. Therefore, this study investigated the inhibitory effect of hexadecyl pyridinium chloride on SARS-CoV-2 in vitro . Vero cells infected with SARS-CoV-2 were used to determine the disinfection effect;the CCK-8 method was used to determine cytotoxicity, and viral load was determined by real-time PCR. The results showed that hexadecyl pyridinium chloride has no obvious cytotoxic effect on Vero cells in the concentration range 0.0125–0.05 mg/mL. The in vitro experiments showed that hexadecyl pyridinium chloride significantly inhibits the virus at concentrations of 0.1 mg/mL or above at 2 min of action. Thus, the results provide experimental support for the use of hexadecyl pyridinium chloride in stomatological hospitals.

4.
J Int Med Res ; 49(12): 3000605211063695, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1575873

ABSTRACT

OBJECTIVE: To evaluate the antiviral activity of the oral disinfectant povidone-iodine (PVP-I) against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV2) in vitro. METHODS: The cytotoxic effects of PVP-I were determined in Vero and Calu-3 cell lines using that by Cell Counting Kit-8 assay. Viral load in the cell culture medium above infected cells was quantitated using real-time polymerase chain reaction. The cytopathic effect (CPE) and viral infective rate were observed by immunofluorescence microscopy. RESULTS: PVP-I at a concentration >0.5 mg/ml in contact with SARS-CoV-2 for 30 s, 1 min, 2 min and 5 min showed up to 99% viral inhibition. For in vitro testing, upon exposure for 1 min, PVP-I showed a virucidal effect. PVP-I had no cytotoxic effects at the range of concentrations tested (0.125-1 mg/ml; CC50 > 2.75 mM) in Vero and Calu-3 cells. CONCLUSION: These results demonstrate that the ideal contact time was 1 min and the optimal concentration was 1 mg/ml, which provides an experimental basis for the use of oral disinfectants in dental hospitals.


Subject(s)
COVID-19 , SARS-CoV-2 , Cell Line , Humans , Povidone-Iodine/pharmacology , RNA, Viral
5.
Cell Res ; 31(1): 25-36, 2021 01.
Article in English | MEDLINE | ID: covidwho-1387275

ABSTRACT

Structural principles underlying the composition and synergistic mechanisms of protective monoclonal antibody cocktails are poorly defined. Here, we exploited antibody cooperativity to develop a therapeutic antibody cocktail against SARS-CoV-2. On the basis of our previously identified humanized cross-neutralizing antibody H014, we systematically analyzed a fully human naive antibody library and rationally identified a potent neutralizing antibody partner, P17, which confers effective protection in animal model. Cryo-EM studies dissected the nature of the P17 epitope, which is SARS-CoV-2 specific and distinctly different from that of H014. High-resolution structure of the SARS-CoV-2 spike in complex with H014 and P17, together with functional investigations revealed that in a two-antibody cocktail, synergistic neutralization was achieved by S1 shielding and conformational locking, thereby blocking receptor attachment and viral membrane fusion, conferring high potency as well as robustness against viral mutation escape. Furthermore, cluster analysis identified a hypothetical 3rd antibody partner for further reinforcing the cocktail as pan-SARS-CoVs therapeutics.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19 , Epitopes/immunology , SARS-CoV-2/immunology , Single-Chain Antibodies/immunology , Animals , Antibodies, Neutralizing/pharmacology , Antibodies, Viral/pharmacology , COVID-19/immunology , COVID-19/prevention & control , Chlorocebus aethiops , Disease Models, Animal , Humans , Single-Chain Antibodies/pharmacology , Vero Cells
6.
Front Immunol ; 12: 708184, 2021.
Article in English | MEDLINE | ID: covidwho-1346403

ABSTRACT

There is a worldwide pandemic of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection; yet our understanding remains limited on the characteristic of antibodies, especially for dynamic long-term tracking. Sequential serum samples were collected up to 416 days post onset of symptoms (POS) from 102 patients who were hospitalized with coronavirus disease 2019 (COVID-19). Immunoglobulin (Ig)G, IgM, and IgA levels targeting SARS-CoV-2 spike 1 receptor-binding domain (S1-RBD), spike 2 extracellular domain (S2-ECD), and nucleocapsid protein (N) were quantified as well as neutralizing activity. We were pleasantly surprised to find that the antibody remained detective and effective for more than a year POS. We also found the varied reactions of different antibodies as time passed: N-IgA rose most rapidly in the early stage of infection, while S2-IgG was present at a high level in the long time of observation. This study described the long traceable antibody response of the COVID-19 and offered hints about targets to screen for postinfectious immunity and for vaccination development of SARS-CoV-2.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/immunology , SARS-CoV-2/immunology , Aged , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/diagnosis , Coronavirus Nucleocapsid Proteins/immunology , Female , Follow-Up Studies , Hospitalization , Humans , Immunoglobulin Isotypes/blood , Immunoglobulin Isotypes/immunology , Kinetics , Male , Middle Aged , Models, Theoretical , Phosphoproteins/immunology , Protein Domains/immunology , SARS-CoV-2/isolation & purification , Seroconversion , Spike Glycoprotein, Coronavirus/immunology
7.
Vaccines (Basel) ; 9(6)2021 Jun 02.
Article in English | MEDLINE | ID: covidwho-1259638

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus (SARS-CoV) pose a great threat to humanity. Every pandemic involving these coronaviruses has seriously affected human health and economic development. Currently, there are no approved therapeutic drugs against their infections. Therefore, the development of vaccines is particularly important to combat these coronaviruses. In this review, we summarized and analyzed the progress of vaccines against SARS-CoV, MERS-CoV, and SARS-CoV-2, including inactivated vaccines, live attenuated vaccines, subunit vaccines, nucleic acid vaccines, and viral vector vaccines. In addition, we compared the levels of neutralizing antibodies in the serum of patients with these three kinds of coronaviruses at different stages, and their ability and effects against SARS-CoV-2, MERS-CoV, and SARS-CoV. This review provides useful information for vaccine evaluation and analysis.

8.
Cell Res ; 31(1): 25-36, 2021 01.
Article in English | MEDLINE | ID: covidwho-952976

ABSTRACT

Structural principles underlying the composition and synergistic mechanisms of protective monoclonal antibody cocktails are poorly defined. Here, we exploited antibody cooperativity to develop a therapeutic antibody cocktail against SARS-CoV-2. On the basis of our previously identified humanized cross-neutralizing antibody H014, we systematically analyzed a fully human naive antibody library and rationally identified a potent neutralizing antibody partner, P17, which confers effective protection in animal model. Cryo-EM studies dissected the nature of the P17 epitope, which is SARS-CoV-2 specific and distinctly different from that of H014. High-resolution structure of the SARS-CoV-2 spike in complex with H014 and P17, together with functional investigations revealed that in a two-antibody cocktail, synergistic neutralization was achieved by S1 shielding and conformational locking, thereby blocking receptor attachment and viral membrane fusion, conferring high potency as well as robustness against viral mutation escape. Furthermore, cluster analysis identified a hypothetical 3rd antibody partner for further reinforcing the cocktail as pan-SARS-CoVs therapeutics.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19 , Epitopes/immunology , SARS-CoV-2/immunology , Single-Chain Antibodies/immunology , Animals , Antibodies, Neutralizing/pharmacology , Antibodies, Viral/pharmacology , COVID-19/immunology , COVID-19/prevention & control , Chlorocebus aethiops , Disease Models, Animal , Humans , Single-Chain Antibodies/pharmacology , Vero Cells
9.
Cell Discov ; 6(1): 76, 2020 Oct 29.
Article in English | MEDLINE | ID: covidwho-904771

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally with more than 33 million patients diagnosed, taking more than a million lives. Abundant mutations were observed but the functional consequences of these mutations are largely unknown. We report the mutation spectrum, replication dynamics, and infectivity of 11 patient-derived viral isolates in diverse cell lines, including the human lung cancer cell line Calu-3. We observed 46 mutations, including 9 different mutations in the spike gene. Importantly, these viral isolates show significant and consistent variations in replication dynamics and infectivity in tested cell lines, up to a 1500-fold difference in viral titers at 24 h after infecting Calu-3 cells. Moreover, we show that the variations in viral titers among viral isolates are positively correlated with blood clotting function but inversely correlated with the amount of red blood cell and hemoglobin in patients. Therefore, we provide direct evidence that naturally occurring mutations in SARS-CoV-2 can substantially change its replication dynamics and infectivity in diverse human cell lines, with clinical implications in vivo.

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