A group of SARS-like coronaviruses(SL-CoV)have been identified in horseshoe bats.Despite SL-CoVs and SARS-CoV share identical genome structure and high-level sequence similarity,SL-CoV does not bind to the same cellul...A group of SARS-like coronaviruses(SL-CoV)have been identified in horseshoe bats.Despite SL-CoVs and SARS-CoV share identical genome structure and high-level sequence similarity,SL-CoV does not bind to the same cellular receptor as for SARS-CoV and the N-terminus of the S proteins only share 64%amino acid identity,suggesting there are fundamental differences between these two groups of coronaviruses.To gain insight into the basis of this difference,we established a recombinant adenovirus system expressing the S protein from SL-CoV(rAd-Rp3-S)to investigate its immune characterization.Our results showed that immunized mice generated strong humoral immune responses against the SL-CoV S protein.Moreover,a strong cellular immune response demonstrated by elevated IFN-γand IL-6 levels was also observed in these mice.However,the induced antibody from these mice had weaker cross-reaction with the SARS-CoV S protein,and did not neutralize HIV pseudotyped with SARS-CoV S protein.These results demonstrated that the immunogenicity of the SL-CoV S protein is distinct from that of SARS-CoV,which may cause the immunological differences between human SARS-CoV and bat SL-CoV.Furthermore,the recombinant virus could serve as a potential vaccine candidate against bat SL-CoV infection.展开更多
The spike protein(S)of SARS-CoV-2 is responsible for viral attachment and entry,thus a major factor for host suscep-tibility,tissue tropism,virulence and pathogenicity.The S is divided with S1 and S2 region,and the S1...The spike protein(S)of SARS-CoV-2 is responsible for viral attachment and entry,thus a major factor for host suscep-tibility,tissue tropism,virulence and pathogenicity.The S is divided with S1 and S2 region,and the S1 contains the receptor-binding domain(RBD),while the S2 contains the hydrophobic fusion domain for the entry into the host cell.Numerous host proteases have been implicated in the activation of SARS-CoV-2 S through various c leavage sites.In this article,we review host proteases including furin,trypsin,transmembrane protease serine 2(TMPRSS2)and cathepsins in the activation of SARS-CoV-2 S.Many betacoronaviruses including SARS-CoV-2 have polybasic residues at the S1/S2 site which is subjected to the cleavage by furin.The S1/S2 cleavage facilitates more assessable RBD to the receptor ACE2,and the binding triggers further conformational changes and exposure of the S2'site to proteases such as type Il transmembrane serine proteases(TTPRs)including TMPRSS2.In the presence of TMPRSS2 on the target cells,SARS-CoV-2 can utilize a direct entry route by fusion of the viral envelope to the cellular membrane.In the absence of TMPRSS2,SARS-CoV-2 enter target cells via endosomes where multiple cathepsins cleave the S for the successful entry.Additional host proteases involved in the cleavage of the S were discussed.This article also includes roles of 3C-like protease inhibitors which have inhibitory activity against cathepsin L in the entry of SARS-CoV-2,and discussed the dual roles of such inhibitors in virus replication.展开更多
<strong>Aims:</strong> The outbreak of the novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still accountable for millions of deaths wor...<strong>Aims:</strong> The outbreak of the novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still accountable for millions of deaths worldwide and declared as a global pandemic by the World Health Organisation. Despite efforts, there is still limited evidence available on a successful potent inhibitor with a low toxicity profile that can aid in the prevention and/or treatment of COVID-19. This study will focus on four main aspects: 1) screening 19 Food Drug and Administration (FDA) approved drugs using computational molecular docking;2) assessing drug toxicity profiles using biological data;3) recommending potential therapies against COVID-19 and 4) supplementing currently used therapies. <strong>Methods:</strong> 19 FDA approved drugs were investigated against the crystal structure of SARS-CoV-2 protease (6LU7) and SARS-CoV-2 glycoprotein (6VXX) using a computational molecular docking software, Molecular Operating Environment (MOE). Separately, on MOE, 6LU7 and 6VXX were loaded, prepared, and the binding pockets located. The drug’s canonical SMILES were imported, minimised, and docked on the prepared proteins using a search algorithm to establish the highest stability conformation. Drugs were ranked depending on binding properties and biological data to assess safety;steric clashes and voids in the binding site were also analysed. <strong>Results and discussion:</strong> Out of the nineteen (19) FDA approved drugs, 18 inhibited 6LU7 and 13 inhibited 6VXX. High-ranked drugs based on binding properties for 6LU7 were hydroxychloroquine, dexamethasone, naproxen, etoricoxib, and ibuprofen. For 6VXX were hydroxychloroquine, celecoxib, etoricoxib, meloxicam, and parecoxib. Considering safety profile, the top 3 drugs in descending order for 6LU7 were etoricoxib, naproxen and dexamethasone and for 6VXX were etoricoxib, meloxicam, and parecoxib. Compared to the literature, the results were consistent for dexamethasone which was effective against 6LU7. However, for hydroxychloroquine and ibuprofen, there was conflicting literature regarding safety and efficacy. <strong>Conclusion and future work:</strong> The findings suggest that against COVID-19 etoricoxib might be effective as a therapeutic and prophylactic measure. Naproxen and dexamethasone would be more effective as treatment only while meloxicam and parecoxib as prophylaxis. However, future studies are needed to validate these findings. Compared to previous literature, the findings in this study also support the use of dexamethasone over hydroxychloroquine and ibuprofen for COVID-19 based on the binding and safety properties. Despite this, future research should explore the impressive binding properties displayed by hydroxychloroquine and ibuprofen to aid in developing a new drug against COVID-19.展开更多
Infectious Bronchitis (IB) is highly contagious disease of commercial poultry causing substantial economic loses by producing poor quality meat in broilers and effecting production in breeder birds. The causative agen...Infectious Bronchitis (IB) is highly contagious disease of commercial poultry causing substantial economic loses by producing poor quality meat in broilers and effecting production in breeder birds. The causative agent has been reported as most hazardous pathogen among other infectious agent even after being immunized with multi-variant strain vaccine. Currently, different strain such as H-120, 4/91 and D274 have been used extensively for immunoprophylaxis against velogenic strain across Pakistan with minimal protection reported. In current study PCR analysis was used to investigate the molecular nature of IB isolates from Punjab and Sind province of Pakistan in 2016 epidemics. Total of 100 tracheal samples were considered for virus inoculation in 10 days old chicken embryonated eggs. The IBV infected amniotic fluid was neutralized with monoclonal antisera of H-120, 4/91 and D274 strains. The IBV screened samples were subjected for RNA extraction and subsequent to PCR using type specific primer of each strain. The amplified product of 840 bp was sequenced through Sanger sequencing. On the basis of PCR results, four similar amplified products from both regions were obtained showing similarities in agarose gel electrophoresis, but they differ from each other on the basis of nucleotides sequence. Phylogenetic analysis revealed that nucleotide sequences of isolates from Karachi were similar to the IBV H-120, Mass-41 and Connecticut 46 reference strains. Whereas, isolates from the Punjab province are analogous to the Mans-2, Mans-3, 9/41(UK) but did not show significant similarity with other reference strain. Therefore, it is recommended that use of M-41 and H-120 in vaccine production could be effective measure against velogenic infectious agent in Sindh particularly in Karachi, whereas, it would be better to incorporate either of the variant GQ281656.1, AY279533.1 in vaccine because of their highest level of resemblance with genetically sequenced isolates from Lahore and its surroundings.展开更多
Objective To comprehend the reiation of tobacco glycoprotein (TGP) to Buerger,s disease.Metbods TGP was isolated from crude tobacco leaves by basic immunologic techniques. Serum anti- TGPantibodies were tested by West...Objective To comprehend the reiation of tobacco glycoprotein (TGP) to Buerger,s disease.Metbods TGP was isolated from crude tobacco leaves by basic immunologic techniques. Serum anti- TGPantibodies were tested by Western blot analysis in 11 patients with Buerger,s disease, 15 healthy male smokers and11 nonsmoking healthy male subjects. Results 1. TGP is a dark brown protein of molecular weight 14000. It maybe a subunit of some high molecular weight protein, and exists in crude tobacco leaves. 2. Western blot analysisshowed that 81.81% of patients with Buerger’s disease (9/11), 33.33% of healthy smokers (5/15) and 27.27% ofhealthy nonsmokers (3/11) had serum anti- TGP antibodies. There was significant dtherence between patientswith Buerger,s disease and two control groups (P<0.05), and no signilicant dtherence between both control groups(P>0.05). Conclusion TGP does play an important role in the pathogenesis of Buerger’s disease. As anti - TGPantibodies are also found in some control subjects, it is speculated that other etiologic factors might coordinatelycontribute to the specifc vascular response to TGP in susceptible subjects.展开更多
Despite the global decline in the severity of the coronavirus disease 2019 (COVID-19) cases, the disease stillrepresents a major concern to the relevant scientific and medical communities. The primary concern of drug ...Despite the global decline in the severity of the coronavirus disease 2019 (COVID-19) cases, the disease stillrepresents a major concern to the relevant scientific and medical communities. The primary concern of drug scientists,virologists, and other concerned specialists in this respect is to find ready-to-use suitable and potent anticoronaviraltherapies that are broadly effective against the different species/strains of the coronaviruses in general, not only againstthe current and previous coronaviruses (e.g., the recently-appeared severe acute respiratory syndrome coronavirus 2“SARS-CoV-2”), i.e., effective antiviral agents for treatment and/or prophylaxis of any coronaviral infections, includingthose of the coming ones from the next species and strains (if any). As an expert in this field, I tried, in this up-to-dateperspective “viewpoint” article, to evaluate the suitability and applicability of using the currently-availableanticoronaviral agents for the next coronavirus diseases (COVIDs) and coronaviral pandemics, highlighting the mostimportant general guidelines that should be considered in the next pandemics from the therapeutic points of view.展开更多
基金supported by the State Key Program for Basic Research Grant(2005CB523004)from the Chinese Ministry of Science and Technologythe Knowledge Innovation Program Key Project administered by the Chinese Academy of Sciences(KSCX1-YW-R-07)
文摘A group of SARS-like coronaviruses(SL-CoV)have been identified in horseshoe bats.Despite SL-CoVs and SARS-CoV share identical genome structure and high-level sequence similarity,SL-CoV does not bind to the same cellular receptor as for SARS-CoV and the N-terminus of the S proteins only share 64%amino acid identity,suggesting there are fundamental differences between these two groups of coronaviruses.To gain insight into the basis of this difference,we established a recombinant adenovirus system expressing the S protein from SL-CoV(rAd-Rp3-S)to investigate its immune characterization.Our results showed that immunized mice generated strong humoral immune responses against the SL-CoV S protein.Moreover,a strong cellular immune response demonstrated by elevated IFN-γand IL-6 levels was also observed in these mice.However,the induced antibody from these mice had weaker cross-reaction with the SARS-CoV S protein,and did not neutralize HIV pseudotyped with SARS-CoV S protein.These results demonstrated that the immunogenicity of the SL-CoV S protein is distinct from that of SARS-CoV,which may cause the immunological differences between human SARS-CoV and bat SL-CoV.Furthermore,the recombinant virus could serve as a potential vaccine candidate against bat SL-CoV infection.
基金National Institutes of Health(NIH)(grants R01 A/130092 and Al161085).
文摘The spike protein(S)of SARS-CoV-2 is responsible for viral attachment and entry,thus a major factor for host suscep-tibility,tissue tropism,virulence and pathogenicity.The S is divided with S1 and S2 region,and the S1 contains the receptor-binding domain(RBD),while the S2 contains the hydrophobic fusion domain for the entry into the host cell.Numerous host proteases have been implicated in the activation of SARS-CoV-2 S through various c leavage sites.In this article,we review host proteases including furin,trypsin,transmembrane protease serine 2(TMPRSS2)and cathepsins in the activation of SARS-CoV-2 S.Many betacoronaviruses including SARS-CoV-2 have polybasic residues at the S1/S2 site which is subjected to the cleavage by furin.The S1/S2 cleavage facilitates more assessable RBD to the receptor ACE2,and the binding triggers further conformational changes and exposure of the S2'site to proteases such as type Il transmembrane serine proteases(TTPRs)including TMPRSS2.In the presence of TMPRSS2 on the target cells,SARS-CoV-2 can utilize a direct entry route by fusion of the viral envelope to the cellular membrane.In the absence of TMPRSS2,SARS-CoV-2 enter target cells via endosomes where multiple cathepsins cleave the S for the successful entry.Additional host proteases involved in the cleavage of the S were discussed.This article also includes roles of 3C-like protease inhibitors which have inhibitory activity against cathepsin L in the entry of SARS-CoV-2,and discussed the dual roles of such inhibitors in virus replication.
文摘<strong>Aims:</strong> The outbreak of the novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still accountable for millions of deaths worldwide and declared as a global pandemic by the World Health Organisation. Despite efforts, there is still limited evidence available on a successful potent inhibitor with a low toxicity profile that can aid in the prevention and/or treatment of COVID-19. This study will focus on four main aspects: 1) screening 19 Food Drug and Administration (FDA) approved drugs using computational molecular docking;2) assessing drug toxicity profiles using biological data;3) recommending potential therapies against COVID-19 and 4) supplementing currently used therapies. <strong>Methods:</strong> 19 FDA approved drugs were investigated against the crystal structure of SARS-CoV-2 protease (6LU7) and SARS-CoV-2 glycoprotein (6VXX) using a computational molecular docking software, Molecular Operating Environment (MOE). Separately, on MOE, 6LU7 and 6VXX were loaded, prepared, and the binding pockets located. The drug’s canonical SMILES were imported, minimised, and docked on the prepared proteins using a search algorithm to establish the highest stability conformation. Drugs were ranked depending on binding properties and biological data to assess safety;steric clashes and voids in the binding site were also analysed. <strong>Results and discussion:</strong> Out of the nineteen (19) FDA approved drugs, 18 inhibited 6LU7 and 13 inhibited 6VXX. High-ranked drugs based on binding properties for 6LU7 were hydroxychloroquine, dexamethasone, naproxen, etoricoxib, and ibuprofen. For 6VXX were hydroxychloroquine, celecoxib, etoricoxib, meloxicam, and parecoxib. Considering safety profile, the top 3 drugs in descending order for 6LU7 were etoricoxib, naproxen and dexamethasone and for 6VXX were etoricoxib, meloxicam, and parecoxib. Compared to the literature, the results were consistent for dexamethasone which was effective against 6LU7. However, for hydroxychloroquine and ibuprofen, there was conflicting literature regarding safety and efficacy. <strong>Conclusion and future work:</strong> The findings suggest that against COVID-19 etoricoxib might be effective as a therapeutic and prophylactic measure. Naproxen and dexamethasone would be more effective as treatment only while meloxicam and parecoxib as prophylaxis. However, future studies are needed to validate these findings. Compared to previous literature, the findings in this study also support the use of dexamethasone over hydroxychloroquine and ibuprofen for COVID-19 based on the binding and safety properties. Despite this, future research should explore the impressive binding properties displayed by hydroxychloroquine and ibuprofen to aid in developing a new drug against COVID-19.
文摘Infectious Bronchitis (IB) is highly contagious disease of commercial poultry causing substantial economic loses by producing poor quality meat in broilers and effecting production in breeder birds. The causative agent has been reported as most hazardous pathogen among other infectious agent even after being immunized with multi-variant strain vaccine. Currently, different strain such as H-120, 4/91 and D274 have been used extensively for immunoprophylaxis against velogenic strain across Pakistan with minimal protection reported. In current study PCR analysis was used to investigate the molecular nature of IB isolates from Punjab and Sind province of Pakistan in 2016 epidemics. Total of 100 tracheal samples were considered for virus inoculation in 10 days old chicken embryonated eggs. The IBV infected amniotic fluid was neutralized with monoclonal antisera of H-120, 4/91 and D274 strains. The IBV screened samples were subjected for RNA extraction and subsequent to PCR using type specific primer of each strain. The amplified product of 840 bp was sequenced through Sanger sequencing. On the basis of PCR results, four similar amplified products from both regions were obtained showing similarities in agarose gel electrophoresis, but they differ from each other on the basis of nucleotides sequence. Phylogenetic analysis revealed that nucleotide sequences of isolates from Karachi were similar to the IBV H-120, Mass-41 and Connecticut 46 reference strains. Whereas, isolates from the Punjab province are analogous to the Mans-2, Mans-3, 9/41(UK) but did not show significant similarity with other reference strain. Therefore, it is recommended that use of M-41 and H-120 in vaccine production could be effective measure against velogenic infectious agent in Sindh particularly in Karachi, whereas, it would be better to incorporate either of the variant GQ281656.1, AY279533.1 in vaccine because of their highest level of resemblance with genetically sequenced isolates from Lahore and its surroundings.
文摘Objective To comprehend the reiation of tobacco glycoprotein (TGP) to Buerger,s disease.Metbods TGP was isolated from crude tobacco leaves by basic immunologic techniques. Serum anti- TGPantibodies were tested by Western blot analysis in 11 patients with Buerger,s disease, 15 healthy male smokers and11 nonsmoking healthy male subjects. Results 1. TGP is a dark brown protein of molecular weight 14000. It maybe a subunit of some high molecular weight protein, and exists in crude tobacco leaves. 2. Western blot analysisshowed that 81.81% of patients with Buerger’s disease (9/11), 33.33% of healthy smokers (5/15) and 27.27% ofhealthy nonsmokers (3/11) had serum anti- TGP antibodies. There was significant dtherence between patientswith Buerger,s disease and two control groups (P<0.05), and no signilicant dtherence between both control groups(P>0.05). Conclusion TGP does play an important role in the pathogenesis of Buerger’s disease. As anti - TGPantibodies are also found in some control subjects, it is speculated that other etiologic factors might coordinatelycontribute to the specifc vascular response to TGP in susceptible subjects.
文摘Despite the global decline in the severity of the coronavirus disease 2019 (COVID-19) cases, the disease stillrepresents a major concern to the relevant scientific and medical communities. The primary concern of drug scientists,virologists, and other concerned specialists in this respect is to find ready-to-use suitable and potent anticoronaviraltherapies that are broadly effective against the different species/strains of the coronaviruses in general, not only againstthe current and previous coronaviruses (e.g., the recently-appeared severe acute respiratory syndrome coronavirus 2“SARS-CoV-2”), i.e., effective antiviral agents for treatment and/or prophylaxis of any coronaviral infections, includingthose of the coming ones from the next species and strains (if any). As an expert in this field, I tried, in this up-to-dateperspective “viewpoint” article, to evaluate the suitability and applicability of using the currently-availableanticoronaviral agents for the next coronavirus diseases (COVIDs) and coronaviral pandemics, highlighting the mostimportant general guidelines that should be considered in the next pandemics from the therapeutic points of view.
