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1.
J Clin Invest ; 2022 Mar 22.
Article in English | MEDLINE | ID: covidwho-1752968

ABSTRACT

BACKGROUND: The Delta and Omicron variants of SARS-CoV-2 are currently responsible for breakthrough infections due to waning immunity. We report phase 1/2 trial results of UB-612, a multitope subunit vaccine containing S1-RBD-sFc protein and rationally-designed promiscuous peptides representing Sarbecovirus conserved Th and CTL epitopes on the nucleocapsid (N), membrane (M) and spike (S2) proteins. METHODS: We conducted a phase-1 primary 2-dose (28-day apart) trial of 10-, 30-, or 100-µg UB-612 in sixty healthy young adults aged 20-55 years, and fifty of them were boosted with 100-µg of UB-612 ~7-9 months post-2nd dose. A separate placebo-controlled and randomized phase-2 study was conducted with two doses of 100-µg UB-612 (n = 3,875, aged 18-85 years). We evaluated interim safety and immunogenicity of the phase-1 until 14 days post-3rd (booster) dose and of the phase-2 until 28 days post-2nd dose. RESULTS: No vaccine-related serious adverse events (SAE) were recorded. The most common solicited AEs were injection site pain and fatigue, mostly mild and transient. In both trials, UB-612 elicited respective neutralizing antibody titers similar to a panel of human convalescent sera. The most striking findings were: long-lasting viral-neutralizing antibodies and broad T-cell immunity against SARS-CoV2 Variants of Concern (VoCs) including Delta and Omicron, and a strong booster-recalled memory immunity with high cross-reactive neutralizing titers against the Delta and Omicron variants. CONCLUSION: UB-612 has presented a favorable safety profile, potent booster effect against VoCs, and long-lasting B- and broad T-cell immunity that warrants further development for both primary immunization and heterologous boosting of other COVID-19 vaccines. CLINICAL TRIALS: gov: NCT04545749, NCT04773067 and NCT04967742. FUNDING: United Biomedical Inc., Asia, Vaxxinity Inc., and Taiwan Centers for Disease Control, Ministry of Health and Welfare.

2.
Vaccines (Basel) ; 10(2)2022 Feb 17.
Article in English | MEDLINE | ID: covidwho-1708024

ABSTRACT

BACKGROUND: The ChAdOx1 nCoV-19 vaccine has been widely administered against SARS-CoV-2 infection; however, data regarding its immunogenicity, reactogenicity, and potential differences in responses among Asian populations remain scarce. METHODS: 270 participants without prior COVID-19 were enrolled to receive ChAdOx1 nCoV-19 vaccination with a prime-boost interval of 8-9 weeks. Their specific SARS-CoV-2 antibodies, neutralizing antibody titers (NT50), platelet counts, and D-dimer levels were analyzed before and after vaccination. RESULTS: The seroconversion rates of anti-RBD and anti-spike IgG at day 28 after a boost vaccination (BD28) were 100% and 95.19%, respectively. Anti-RBD and anti-spike IgG levels were highly correlated (r = 0.7891), which were 172.9 ± 170.4 and 179.3 ± 76.88 BAU/mL at BD28, respectively. The geometric mean concentrations (GMCs) of NT50 for all participants increased to 132.9 IU/mL (95% CI 120.0-147.1) at BD28 and were highly correlated with anti-RBD and anti-spike IgG levels (r = 0.8248 and 0.7474, respectively). Body weight index was statistically significantly associated with anti-RBD IgG levels (p = 0.035), while female recipients had higher anti-spike IgG levels (p = 0.038). The GMCs of NT50 declined with age (p = 0.0163) and were significantly different across age groups (159.7 IU/mL for 20-29 years, 99.4 IU/mL for ≥50 years, p = 0.0026). Injection-site pain, fever, and fatigue were the major reactogenicity, which were more pronounced after prime vaccination and in younger participants (<50 years). Platelet counts decreased and D-dimer levels increased after vaccination but were not clinically relevant. No serious adverse events or deaths were observed. CONCLUSION: The vaccine is well-tolerated and elicited robust humoral immunity against SARS-CoV-2 after standard prime-boost vaccination in Taiwanese recipients.

3.
Lancet Respir Med ; 9(12): 1396-1406, 2021 12.
Article in English | MEDLINE | ID: covidwho-1621134

ABSTRACT

BACKGROUND: MVC-COV1901, a recombinant protein vaccine containing pre-fusion-stabilised spike protein S-2P adjuvanted with CpG 1018 and aluminium hydroxide, has been shown to be well tolerated with a good safety profile in healthy adults aged 20-49 years in a phase 1 trial, and provided a good cellular and humoral immune responses. We present the interim safety, tolerability, and immunogenicity results of a phase 2 clinical trial of the MVC-COV1901 vaccine in Taiwan. METHODS: This is a large-scale, double-blind, randomised, placebo-controlled phase 2 trial done at ten medical centres and one regional hospital in Taiwan. Individuals aged 20 years or older who were generally healthy or had stable pre-existing medical conditions were eligible for enrolment. Exclusion criteria included (but were not limited to) travel overseas within 14 days of screening, intention to travel overseas within 6 months of the screening visit, and the absence of prespecified medical conditions, including immunosuppressive illness, a history of autoimmune disease, malignancy with risk to recur, a bleeding disorder, uncontrolled HIV infection, uncontrolled hepatitis B and C virus infections, SARS-CoV-1 or SARS-CoV-2 infections, an allergy to any vaccine, or a serious medical condition that could interfere with the study. Study participants were randomly assigned (6:1) to receive two doses of either MVC-COV1901 or placebo, administered via intramuscular injection on day 1 and day 29. MVC-COV1901 contained 15 µg of S-2P protein adjuvanted with 750 µg CpG 1018 and 375 µg aluminium hydroxide in a 0·5 mL aqueous solution, and the placebo contained the same volume of saline. Randomisation was done centrally by use of an interactive web response system, stratified by age (≥20 to <65 years and ≥65 years). Participants and investigators were masked to group assignment. The primary outcomes were to evaluate the safety, tolerability, and immunogenicity of MVC-COV1901 from day 1 (the day of the first dose) to day 57 (28 days after the second dose). Safety was assessed in all participants who received at least one dose. Immunogenicity was assessed by measuring geometric mean titres (GMTs) and seroconversion rates of neutralising antibody and antigen-specific IgG in the per-protocol population. This study is registered with ClinicalTrials.gov, NCT04695652. FINDINGS: Of 4173 individuals screened between Dec 30, 2020, and April 2, 2021, 3854 were enrolled and randomly assigned: 3304 to the MVC-COV1901 group and 550 to the placebo group. A total of 3844 participants (3295 in the MVC-COV1901 group and 549 in the placebo group) were included in the safety analysis set, and 1053 participants (903 and 150) had received both doses and were included in the per-protocol immunogenicity analysis set. From the start of this phase 2 trial to the time of interim analysis, no vaccine-related serious adverse events were recorded. The most common solicited adverse events in all study participants were pain at the injection site (2346 [71·2%] of 3295 in the MVC-COV1901 group and 128 [23·3%] of 549 in the placebo group), and malaise or fatigue (1186 [36·0%] and 163 [29·7%]). Fever was rarely reported (23 [0·7%] and two [0·4%]). At 28 days after the second dose of MVC-COV1901, the wild-type SARS-CoV-2 neutralising antibody GMT was 662·3 (95% CI 628·7-697·8; 408·5 IU/mL), the GMT ratio (geometric mean fold increase in titres at day 57 vs baseline) was 163·2 (155·0-171·9), and the seroconversion rate was 99·8% (95% CI 99·2-100·0). INTERPRETATION: MVC-COV1901 has a good safety profile and elicits promising immunogenicity responses. These data support MVC-COV1901 to enter phase 3 efficacy trials. FUNDING: Medigen Vaccine Biologics and Taiwan Centres for Disease Control, Ministry of Health and Welfare.


Subject(s)
Adjuvants, Immunologic , Aluminum Hydroxide , COVID-19 Vaccines/immunology , COVID-19 , HIV Infections , Oligodeoxyribonucleotides , Adult , Aged , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Double-Blind Method , Humans , Middle Aged , SARS-CoV-2 , Taiwan , Young Adult
4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296799

ABSTRACT

A post-hoc analysis of the phase 2 data was performed for the SARS-COV-2 subunit protein vaccine MVC-COV1901. Anti-spike IgG, neutralization assays with live virus and pseudovirus were used to demonstrate age-dependent vaccine-induced antibody response to the vaccine. Results showed that an association exists between age and immune responses to the vaccine, providing further support for the need of booster shots, especially for the older age groups.

5.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-296105

ABSTRACT

Summary Background We have assessed the safety and immunogenicity of the COVID-19 vaccine MVC-COV1901, a recombinant protein vaccine containing prefusion-stabilized spike protein S-2P adjuvanted with CpG 1018 and aluminium hydroxide. Methods This is a phase 2, prospective, randomised, double-blind, placebo-controlled, and multi-centre study to evaluate the safety, tolerability, and immunogenicity of the SARS-CoV-2 vaccine candidate MVC-COV1901. The study comprised 3,844 participants of ≥ 20 years who were generally healthy or with stable pre-existing medical conditions. The study participants were randomly assigned in a 6:1 ratio to receive either MVC-COV1901 containing 15 μg of S-2P protein or placebo containing saline. Participants received two doses of MVC-COV1901 or placebo, administered 28 days apart via intramuscular injection. The primary outcomes were to evaluate the safety, tolerability, and immunogenicity of MVC-COV1901 from Day 1 (the day of first vaccination) to Day 57 (28 days after the second dose). Immunogenicity of MVC-COV1901 was assessed through geometric mean titres (GMT) and seroconversion rates (SCR) of neutralising antibody and antigen-specific immunoglobulin. This clinical trial is registered at ClinicalTrials.gov: NCT04695652 . Findings From the start of this phase 2 trial to the time of interim analysis, no vaccine-related Serious Adverse Events (SAEs) were recorded. The most common solicited adverse events across all study participants were pain at the injection site (64%), and malaise/fatigue (35%). Fever was rarely reported (<1%). For all participants in the MVC-COV1901 group, at 28 days after the second dose against wild type SARS-CoV-2 virus, the GMT was 662·3 (408 IU/mL), the GMT ratio was 163·2, and the seroconversion rate was 99·8%. Interpretation MVC-COV1901 shows good safety profiles and promising immunogenicity responses. The current data supports MVC-COV1901 to enter phase 3 efficacy trials and could enable regulatory considerations for Emergency Use Authorisation (EUA). Funding Medigen Vaccine Biologics Corporation and Taiwan Centres for Disease Control.

6.
EBioMedicine ; 74: 103712, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1536515

ABSTRACT

BACKGROUND: Despite clinical success with anti-spike vaccines, the effectiveness of neutralizing antibodies and vaccines has been compromised by rapidly spreading SARS-CoV-2 variants. Viruses can hijack the glycosylation machinery of host cells to shield themselves from the host's immune response and attenuate antibody efficiency. However, it remains unclear if targeting glycosylation on viral spike protein can impair infectivity of SARS-CoV-2 and its variants. METHODS: We adopted flow cytometry, ELISA, and BioLayer interferometry approaches to assess binding of glycosylated or deglycosylated spike with ACE2. Viral entry was determined by luciferase, immunoblotting, and immunofluorescence assays. Genome-wide association study (GWAS) revealed a significant relationship between STT3A and COVID-19 severity. NF-κB/STT3A-regulated N-glycosylation was investigated by gene knockdown, chromatin immunoprecipitation, and promoter assay. We developed an antibody-drug conjugate (ADC) that couples non-neutralization anti-spike antibody with NGI-1 (4G10-ADC) to specifically target SARS-CoV-2-infected cells. FINDINGS: The receptor binding domain and three distinct SARS-CoV-2 surface N-glycosylation sites among 57,311 spike proteins retrieved from the NCBI-Virus-database are highly evolutionarily conserved (99.67%) and are involved in ACE2 interaction. STT3A is a key glycosyltransferase catalyzing spike glycosylation and is positively correlated with COVID-19 severity. We found that inhibiting STT3A using N-linked glycosylation inhibitor-1 (NGI-1) impaired SARS-CoV-2 infectivity and that of its variants [Alpha (B.1.1.7) and Beta (B.1.351)]. Most importantly, 4G10-ADC enters SARS-CoV-2-infected cells and NGI-1 is subsequently released to deglycosylate spike protein, thereby reinforcing the neutralizing abilities of antibodies, vaccines, or convalescent sera and reducing SARS-CoV-2 variant infectivity. INTERPRETATION: Our results indicate that targeting evolutionarily-conserved STT3A-mediated glycosylation via an ADC can exert profound impacts on SARS-CoV-2 variant infectivity. Thus, we have identified a novel deglycosylation method suitable for eradicating SARS-CoV-2 variant infection in vitro. FUNDING: A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.


Subject(s)
Benzamides/pharmacology , COVID-19/drug therapy , Glycosylation/drug effects , Hexosyltransferases/antagonists & inhibitors , Membrane Proteins/antagonists & inhibitors , Sulfonamides/pharmacology , Virus Internalization/drug effects , A549 Cells , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Cell Line , HEK293 Cells , Hexosyltransferases/metabolism , Humans , Membrane Proteins/metabolism , Mice , Mice, Inbred C57BL , SARS-CoV-2/growth & development , Spike Glycoprotein, Coronavirus/metabolism
7.
J Biomed Sci ; 28(1): 80, 2021 Nov 23.
Article in English | MEDLINE | ID: covidwho-1533257

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), an RNA virus with a high mutation rate. Importantly, several currently circulating SARS-CoV-2 variants are associated with loss of efficacy for both vaccines and neutralizing antibodies. METHODS: We analyzed the binding activity of six highly potent antibodies to the spike proteins of SARS-CoV-2 variants, assessed their neutralizing abilities with pseudovirus and authentic SARS-CoV-2 variants and evaluate efficacy of antibody cocktail in Delta SARS-CoV-2-infected hamster models as prophylactic and post-infection treatments. RESULTS: The tested RBD-chAbs, except RBD-chAb-25, maintained binding ability to spike proteins from SARS-CoV-2 variants. However, only RBD-chAb-45 and -51 retained neutralizing activities; RBD-chAb-1, -15, -25 and -28 exhibited diminished neutralization for all SARS-CoV-2 variants. Notably, several cocktails of our antibodies showed low IC50 values (3.35-27.06 ng/ml) against the SARS-CoV-2 variant pseudoviruses including United Kingdom variant B.1.1.7 (Alpha), South Africa variant B.1.351 (Beta), Brazil variant P1 (Gamma), California variant B.1.429 (Epsilon), New York variant B.1.526 (Iota), and India variants, B.1.617.1 (Kappa) and B.1.617.2 (Delta). RBD-chAb-45, and -51 showed PRNT50 values 4.93-37.54 ng/ml when used as single treatments or in combination with RBD-chAb-15 or -28, according to plaque assays with authentic Alpha, Gamma and Delta SARS-CoV-2 variants. Furthermore, the antibody cocktail of RBD-chAb-15 and -45 exhibited potent prophylactic and therapeutic effects in Delta SARS-CoV-2 variant-infected hamsters. CONCLUSIONS: The cocktail of RBD-chAbs exhibited potent neutralizing activities against SARS-CoV-2 variants. These antibody cocktails are highly promising candidate tools for controlling new SARS-CoV-2 variants, including Delta.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/therapeutic use , COVID-19/drug therapy , COVID-19/genetics , Humans , Rabbits , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics
8.
Applied Sciences ; 11(22):10661, 2021.
Article in English | MDPI | ID: covidwho-1512088

ABSTRACT

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as a serious threat to human health worldwide. The inactivation of SARS-CoV-2 on object surfaces and in the indoor air might help to halt the COVID-19 pandemic. Far-ultraviolet light (UVC) disinfection has been proven to be highly effective against viruses and bacteria. To understand the wavelength and duration of UVC radiation required for SARS-CoV-2 inactivation, we examined the efficacy of UVC light prototype devices with the wavelengths of 275, 254, and 222 nm. The disinfection effectiveness was determined by cell-based assays including the median tissue culture infectious dose (TCID50) and an immunofluorescent assay on African green monkey kidney epithelial Vero E6 cells. Among the three prototypes, the UVC LED (275 nm) had the best virucidal activity with a log-reduction value (LRV) >6 after 10 s of exposure. The mercury lamp (254 nm) reached similar virucidal activity after 20 s of exposure. However, the excimer lamp (222 nm) showed limited anti-SARS-CoV-2 activity with a LRV < 2 after 40 s of exposure. Overall, in comparison, the UVC LED (275 nm) exhibited superior SARS-CoV-2 disinfection activity than the mercury lamp (254 nm) and the excimer lamp (222 nm).

9.
J Clin Invest ; 131(21)2021 11 01.
Article in English | MEDLINE | ID: covidwho-1495789

ABSTRACT

To explore how the immune system controls clearance of SARS-CoV-2, we used a single-cell, mass cytometry-based proteomics platform to profile the immune systems of 21 patients who had recovered from SARS-CoV-2 infection without need for admission to an intensive care unit or for mechanical ventilation. We focused on receptors involved in interactions between immune cells and virus-infected cells. We found that the diversity of receptor repertoires on natural killer (NK) cells was negatively correlated with the viral clearance rate. In addition, NK subsets expressing the receptor DNAM1 were increased in patients who more rapidly recovered from infection. Ex vivo functional studies revealed that NK subpopulations with high DNAM1 expression had cytolytic activities in response to target cell stimulation. We also found that SARS-CoV-2 infection induced the expression of CD155 and nectin-4, ligands of DNAM1 and its paired coinhibitory receptor TIGIT, which counterbalanced the cytolytic activities of NK cells. Collectively, our results link the cytolytic immune responses of NK cells to the clearance of SARS-CoV-2 and show that the DNAM1 pathway modulates host-pathogen interactions during SARS-CoV-2 infection.


Subject(s)
COVID-19/immunology , COVID-19/virology , Killer Cells, Natural/immunology , Receptors, Natural Killer Cell/immunology , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Animals , Antigens, Differentiation, T-Lymphocyte/immunology , Cell Adhesion Molecules/immunology , Cohort Studies , Cytotoxicity, Immunologic , Female , Heterografts , Host Microbial Interactions/immunology , Humans , Immunophenotyping , In Vitro Techniques , Ligands , Male , Mice , Mice, SCID , Middle Aged , NK Cell Lectin-Like Receptor Subfamily D/immunology , Pandemics , Receptors, Immunologic/immunology , Receptors, Virus/immunology , Viral Load , Young Adult
10.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-291772

ABSTRACT

SARS-CoV-2 breakthrough infection occurs due to waning immunity time-to-vaccine, to which the globally-dominant, highly-contagious Delta variant is behind the scene. In the primary 2-dose and booster series of clinical Phase-1 trial, UB-612 vaccine, which contains S1-RBD and synthetic Th/CTL peptide pool for activation of humoral and T-cell immunity, induces substantial, prolonged viral-neutralizing antibodies that goes parallel with a long-lasting T-cell immunity;and a booster (3rd ) dose can prompt recall of memory immunity to induce profound, striking antibodies with the highest level of 50% viral-neutralizing GMT titers against live Delta variant reported for any vaccine. The unique design of S1-RBD only plus multitope T-cell peptides may have underpinned UB-612’s potent anti-Delta effect, while the other full S protein-based vaccines are affected additionally by mutations in the N-terminal domain sequence which contains additional neutralizing epitopes. UB-612, safe and well-tolerated, could be effective for boosting other vaccine platforms that have shown modest homologous boosting. [Funded by United Biomedical Inc., Asia;ClinicalTrials.gov ID: NCT04967742 and NCT04545749]

11.
PLoS Pathog ; 17(10): e1009704, 2021 10.
Article in English | MEDLINE | ID: covidwho-1484866

ABSTRACT

Development of effective therapeutics for mitigating the COVID-19 pandemic is a pressing global need. Neutralizing antibodies are known to be effective antivirals, as they can be rapidly deployed to prevent disease progression and can accelerate patient recovery without the need for fully developed host immunity. Here, we report the generation and characterization of a series of chimeric antibodies against the receptor-binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. Some of these antibodies exhibit exceptionally potent neutralization activities in vitro and in vivo, and the most potent of our antibodies target three distinct non-overlapping epitopes within the RBD. Cryo-electron microscopy analyses of two highly potent antibodies in complex with the SARS-CoV-2 spike protein suggested they may be particularly useful when combined in a cocktail therapy. The efficacy of this antibody cocktail was confirmed in SARS-CoV-2-infected mouse and hamster models as prophylactic and post-infection treatments. With the emergence of more contagious variants of SARS-CoV-2, cocktail antibody therapies hold great promise to control disease and prevent drug resistance.


Subject(s)
Antibodies, Neutralizing/pharmacology , Antibodies, Viral/pharmacology , COVID-19/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Cricetinae , Disease Models, Animal , Female , Male , Mice
12.
PLoS One ; 16(9): e0257191, 2021.
Article in English | MEDLINE | ID: covidwho-1412845

ABSTRACT

COVID-19 in humans is caused by Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that belongs to the beta family of coronaviruses. SARS-CoV-2 causes severe respiratory illness in 10-15% of infected individuals and mortality in 2-3%. Vaccines are urgently needed to prevent infection and to contain viral spread. Although several mRNA- and adenovirus-based vaccines are highly effective, their dependence on the "cold chain" transportation makes global vaccination a difficult task. In this context, a stable lyophilized vaccine may present certain advantages. Accordingly, establishing additional vaccine platforms remains vital to tackle SARS-CoV-2 and any future variants that may arise. Vaccinia virus (VACV) has been used to eradicate smallpox disease, and several attenuated viral strains with enhanced safety for human applications have been developed. We have generated two candidate SARS-CoV-2 vaccines based on two vaccinia viral strains, MVA and v-NY, that express full-length SARS-CoV-2 spike protein. Whereas MVA is growth-restricted in mammalian cells, the v-NY strain is replication-competent. We demonstrate that both candidate recombinant vaccines induce high titers of neutralizing antibodies in C57BL/6 mice vaccinated according to prime-boost regimens. Furthermore, our vaccination regimens generated TH1-biased immune responses in mice. Most importantly, prime-boost vaccination of a Syrian hamster infection model with MVA-S and v-NY-S protected the hamsters against SARS-CoV-2 infection, supporting that these two vaccines are promising candidates for future development. Finally, our vaccination regimens generated neutralizing antibodies that partially cross-neutralized SARS-CoV-2 variants of concern.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/immunology , Vaccinia virus/genetics , Animals , Antibodies, Neutralizing/analysis , Antibodies, Neutralizing/immunology , COVID-19/virology , COVID-19 Vaccines/genetics , Female , Immunization, Secondary , Lung/pathology , Male , Mesocricetus , Mice , Mice, Inbred C57BL , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry
13.
Front Pharmacol ; 12: 706901, 2021.
Article in English | MEDLINE | ID: covidwho-1394795

ABSTRACT

Remdesivir, a prodrug targeting RNA-dependent-RNA-polymerase, and cyclosporine, a calcineurin inhibitor, individually exerted inhibitory activity against human coronavirus OC43 (HCoV-OC43) in HCT-8 and MRC-5 cells at EC50 values of 96 ± 34 ∼ 85 ± 23 nM and 2,920 ± 364 ∼ 4,419 ± 490 nM, respectively. When combined, these two drugs synergistically inhibited HCoV-OC43 in both HCT-8 and MRC-5 cells assayed by immunofluorescence assay (IFA). Remdesivir and cyclosporine also separately reduced IL-6 production induced by HCoV-OC43 in human lung fibroblasts MRC-5 cells with EC50 values of 224 ± 53 nM and 1,292 ± 352 nM, respectively; and synergistically reduced it when combined. Similar trends were observed for SARS-CoV-2, which were 1) separately inhibited by remdesivir and cyclosporine with respective EC50 values of 3,962 ± 303 nM and 7,213 ± 143 nM by IFA, and 291 ± 91 nM and 6,767 ± 1,827 nM by a plaque-formation assay; and 2) synergistically inhibited by their combination, again by IFA and plaque-formation assay. Collectively, these results suggest that the combination of remdesivir and cyclosporine merits further study as a possible treatment for COVID-19 complexed with a cytokine storm.

15.
ACS Pharmacol Transl Sci ; 4(3): 1246, 2021 Jun 11.
Article in English | MEDLINE | ID: covidwho-1387159

ABSTRACT

[This corrects the article DOI: 10.1021/acsptsci.1c00022.].

16.
Int J Mol Sci ; 22(16)2021 Aug 23.
Article in English | MEDLINE | ID: covidwho-1367852

ABSTRACT

The SARS-CoV-2 pseudovirus is a commonly used strategy that mimics certain biological functions of the authentic virus by relying on biological legitimacy at the molecular level. Despite the fact that spike (S), envelope (E), and membrane (M) proteins together wrap up the SARS-CoV-2 virion, most of the reported pseudotype viruses consist of only the S protein. Here, we report that the presence of E and M increased the virion infectivity by promoting the S protein priming. The S, E, and M (SEM)-coated pseudovirion is spherical, containing crown-like spikes on the surface. Both S and SEM pseudoviruses packaged the same amounts of viral RNA, but the SEM virus bound more efficiently to cells stably expressing the viral receptor human angiotensin-converting enzyme II (hACE2) and became more infectious. Using this SEM pseudovirus, we examined the infectivity and antigenic properties of the natural SARS-CoV-2 variants. We showed that some variants have higher infectivity than the original virus and that some render the neutralizing plasma with lower potency. These studies thus revealed possible mechanisms of the dissemination advantage of these variants. Hence, the SEM pseudovirion provides a useful tool to evaluate the viral infectivity and capability of convalescent sera in neutralizing specific SARS-CoV-2 S dominant variants.


Subject(s)
Antibodies, Viral/metabolism , COVID-19/immunology , Coronavirus Envelope Proteins/metabolism , SARS-CoV-2/pathogenicity , Viral Matrix Proteins/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/virology , Cell Line , Coronavirus Envelope Proteins/genetics , Coronavirus Envelope Proteins/immunology , Coronavirus Envelope Proteins/ultrastructure , Cricetinae , Humans , Microscopy, Electron, Transmission , Mutation , Neutralization Tests , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Viral Matrix Proteins/genetics , Viral Matrix Proteins/immunology , Viral Matrix Proteins/ultrastructure , Virion/genetics , Virion/immunology , Virion/metabolism , Virion/ultrastructure
17.
PLoS Pathog ; 17(8): e1009758, 2021 08.
Article in English | MEDLINE | ID: covidwho-1352713

ABSTRACT

Since the pandemic of COVID-19 has intensely struck human society, small animal model for this infectious disease is in urgent need for basic and pharmaceutical research. Although several COVID-19 animal models have been identified, many of them show either minimal or inadequate pathophysiology after SARS-CoV-2 challenge. Here, we describe a new and versatile strategy to rapidly establish a mouse model for emerging infectious diseases in one month by multi-route, multi-serotype transduction with recombinant adeno-associated virus (AAV) vectors expressing viral receptor. In this study, the proposed approach enables profound and enduring systemic expression of SARS-CoV-2-receptor hACE2 in wild-type mice and renders them vulnerable to SARS-CoV-2 infection. Upon virus challenge, generated AAV/hACE2 mice showed pathophysiology closely mimicking the patients with severe COVID-19. The efficacy of a novel therapeutic antibody cocktail RBD-chAbs for COVID-19 was tested and confirmed by using this AAV/hACE2 mouse model, further demonstrating its successful application in drug development.


Subject(s)
COVID-19 , Communicable Diseases, Emerging , Disease Models, Animal , 3T3 Cells , Angiotensin-Converting Enzyme 2/genetics , Animals , Antibodies, Viral/immunology , Antibodies, Viral/therapeutic use , COVID-19/immunology , COVID-19/pathology , COVID-19/physiopathology , Chlorocebus aethiops , Dependovirus/genetics , Humans , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Transduction, Genetic , Vero Cells
18.
J Biomed Sci ; 28(1): 43, 2021 Jun 07.
Article in English | MEDLINE | ID: covidwho-1261273

ABSTRACT

BACKGROUND: Coronavirus disease 19 (COVID-19) first appeared in the city of Wuhan, in the Hubei province of China. Since its emergence, the COVID-19-causing virus, SARS-CoV-2, has been rapidly transmitted around the globe, overwhelming the medical care systems in many countries and leading to more than 3.3 million deaths. Identification of immunological epitopes on the virus would be highly useful for the development of diagnostic tools and vaccines that will be critical to limiting further spread of COVID-19. METHODS: To find disease-specific B-cell epitopes that correspond to or mimic natural epitopes, we used phage display technology to determine the targets of specific antibodies present in the sera of immune-responsive COVID-19 patients. Enzyme-linked immunosorbent assays were further applied to assess competitive antibody binding and serological detection. VaxiJen, BepiPred-2.0 and DiscoTope 2.0 were utilized for B-cell epitope prediction. PyMOL was used for protein structural analysis. RESULTS: 36 enriched peptides were identified by biopanning with antibodies from two COVID-19 patients; the peptides 4 motifs with consensus residues corresponding to two potential B-cell epitopes on SARS-CoV-2 viral proteins. The putative epitopes and hit peptides were then synthesized for validation by competitive antibody binding and serological detection. CONCLUSIONS: The identified B-cell epitopes on SARS-CoV-2 may aid investigations into COVID-19 pathogenesis and facilitate the development of epitope-based serological diagnostics and vaccines.


Subject(s)
COVID-19 , Epitopes, B-Lymphocyte , Peptide Library , SARS-CoV-2 , Viral Proteins , COVID-19/genetics , COVID-19/immunology , Epitopes, B-Lymphocyte/genetics , Epitopes, B-Lymphocyte/immunology , Humans , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Viral Proteins/genetics , Viral Proteins/immunology
19.
Anal Chem ; 93(21): 7690-7698, 2021 06 01.
Article in English | MEDLINE | ID: covidwho-1236048

ABSTRACT

Coronavirus is an enveloped RNA virus that causes mild to severe respiratory diseases in humans, including HKU1-CoV, 229E-CoV, NL63-CoV, OC43-CoV, SARS-CoV, MERS-CoV, and SARS-CoV-2. Due to the outbreak of SARS-CoV-2, it is important to identify the patients and investigate their immune responses. Protein microarray is one of the best platforms to profile the antibodies in the blood because of its fast, multiplexed, and sensitive nature. To fully understand the immune responses and biological specificities, this study developed a human coronavirus (HCoV) protein microarray and included all seven human coronaviruses and three influenza viruses. Each protein was printed in triplicate and formed 14 identical blocks per array. The HCoV protein microarray showed high reproducibility and sensitivity to the monoclonal antibodies against spike and nucleocapsid protein with detection limits of 10-200 pg. The HCoV proteins that were immobilized on the array were properly folded and functional by showing interactions with a known human receptor, e.g., ACE2. By profiling the serum IgG and IgA from 32 COVID-19 patients and 36 healthy patients, the HCoV protein microarray demonstrated 97% sensitivity and 97% specificity with two biomarkers. The results also showed the cross-reactivity of IgG and IgA in COVID-19 patients to spike proteins from various coronaviruses, including that from SARS-CoV, HKU1-CoV, and OC43-CoV. Finally, an innate immune protein named surfactant protein D showed broad affinities to spike proteins in all human coronaviruses. Overall, the HCoV protein microarray is multiplexed, sensitive, and specific, which is useful in diagnosis, immune assessment, biological development, and drug screening.


Subject(s)
COVID-19 , Coronavirus OC43, Human , Humans , Protein Array Analysis , Reproducibility of Results , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
20.
Sci Rep ; 11(1): 8761, 2021 04 22.
Article in English | MEDLINE | ID: covidwho-1199318

ABSTRACT

The COVID-19 pandemic presents an unprecedented challenge to global public health. Rapid development and deployment of safe and effective vaccines are imperative to control the pandemic. In the current study, we applied our adjuvanted stable prefusion SARS-CoV-2 spike (S-2P)-based vaccine, MVC-COV1901, to hamster models to demonstrate immunogenicity and protection from virus challenge. Golden Syrian hamsters immunized intramuscularly with two injections of 1 µg or 5 µg of S-2P adjuvanted with CpG 1018 and aluminum hydroxide (alum) were challenged intranasally with SARS-CoV-2. Prior to virus challenge, the vaccine induced high levels of neutralizing antibodies with 10,000-fold higher IgG level and an average of 50-fold higher pseudovirus neutralizing titers in either dose groups than vehicle or adjuvant control groups. Six days after infection, vaccinated hamsters did not display any weight loss associated with infection and had significantly reduced lung pathology and most importantly, lung viral load levels were reduced to lower than detection limit compared to unvaccinated animals. Vaccination with either 1 µg or 5 µg of adjuvanted S-2P produced comparable immunogenicity and protection from infection. This study builds upon our previous results to support the clinical development of MVC-COV1901 as a safe, highly immunogenic, and protective COVID-19 vaccine.


Subject(s)
Adjuvants, Immunologic/administration & dosage , Aluminum Hydroxide/administration & dosage , COVID-19/prevention & control , Oligodeoxyribonucleotides/administration & dosage , Spike Glycoprotein, Coronavirus/immunology , Aluminum Hydroxide/immunology , Animals , Antibodies, Neutralizing/metabolism , COVID-19/immunology , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/immunology , Cell Line , Cricetinae , Female , Humans , Immunization , Injections, Intramuscular , Oligodeoxyribonucleotides/immunology , SARS-CoV-2/immunology , SARS-CoV-2/physiology , Viral Load/drug effects
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