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1.
Adv Sci (Weinh) ; 9(11): e2105378, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1680239

ABSTRACT

The SARS-CoV-2 Delta (B.1.617.2) strain is a variant of concern (VOC) that has become the dominant strain worldwide in 2021. Its transmission capacity is approximately twice that of the original strain, with a shorter incubation period and higher viral load during infection. Importantly, the breakthrough infections of the Delta variant have continued to emerge in the first-generation vaccine recipients. There is thus an urgent need to develop a novel vaccine with SARS-CoV-2 variants as the major target. Here, receptor binding domain (RBD)-conjugated nanoparticle vaccines targeting the Delta variant, as well as the early and Beta/Gamma strains, are developed. Under both a single-dose and a prime-boost strategy, these RBD-conjugated nanoparticle vaccines induce the abundant neutralizing antibodies (NAbs) and significantly protect hACE2 mice from infection by the authentic SARS-CoV-2 Delta strain, as well as the early and Beta strains. Furthermore, the elicitation of the robust production of broader cross-protective NAbs against almost all the notable SARS-CoV-2 variants including the Omicron variant in rhesus macaques by the third re-boost with trivalent vaccines is found. These results suggest that RBD-based monovalent or multivalent nanoparticle vaccines provide a promising second-generation vaccine strategy for SARS-CoV-2 variants.


Subject(s)
COVID-19 , Nanoparticles , Animals , Broadly Neutralizing Antibodies , COVID-19/prevention & control , Macaca mulatta/metabolism , Mice , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Vaccines, Conjugate
2.
Signal Transduct Target Ther ; 7(1): 7, 2022 01 04.
Article in English | MEDLINE | ID: covidwho-1606287

ABSTRACT

Activation-induced cytidine deaminase (AID) initiates class-switch recombination and somatic hypermutation (SHM) in antibody genes. Protein expression and activity are tightly controlled by various mechanisms. However, it remains unknown whether a signal from the extracellular environment directly affects the AID activity in the nucleus where it works. Here, we demonstrated that a deubiquitinase USP10, which specifically stabilizes nuclear AID protein, can translocate into the nucleus after AKT-mediated phosphorylation at its T674 within the NLS domain. Interestingly, the signals from BCR and TLR1/2 synergistically promoted this phosphorylation. The deficiency of USP10 in B cells significantly decreased AID protein levels, subsequently reducing neutralizing antibody production after immunization with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or human immunodeficiency virus type 1 (HIV-1) nanoparticle vaccines. Collectively, we demonstrated that USP10 functions as an integrator for both BCR and TLR signals and directly regulates nuclear AID activity. Its manipulation could be used for the development of vaccines and adjuvants.


Subject(s)
AIDS Vaccines/immunology , B-Cell Activating Factor/immunology , COVID-19 Vaccines/immunology , Cytidine Deaminase/immunology , HIV-1/immunology , Nanoparticles , SARS-CoV-2/immunology , Signal Transduction/immunology , Ubiquitin Thiolesterase/immunology , Ubiquitination/immunology , AIDS Vaccines/genetics , Animals , B-Cell Activating Factor/genetics , COVID-19 Vaccines/genetics , Cytidine Deaminase/genetics , HEK293 Cells , HIV-1/genetics , Humans , Mice , Mice, Knockout , SARS-CoV-2/genetics , Signal Transduction/genetics , Ubiquitin Thiolesterase/genetics
3.
Signal Transduct Target Ther ; 6(1): 420, 2021 12 14.
Article in English | MEDLINE | ID: covidwho-1585885

ABSTRACT

COVID-19 is identified as a zoonotic disease caused by SARS-CoV-2, which also can cross-transmit to many animals but not mice. Genetic modifications of SARS-CoV-2 or mice enable the mice susceptible to viral infection. Although neither is the natural situation, they are currently utilized to establish mouse infection models. Here we report a direct contact transmission of SARS-CoV-2 variant B.1.351 in wild-type mice. The SARS-CoV-2 (B.1.351) replicated efficiently and induced significant pathological changes in lungs and tracheas, accompanied by elevated proinflammatory cytokines in the lungs and sera. Mechanistically, the receptor-binding domain (RBD) of SARS-CoV-2 (B.1.351) spike protein turned to a high binding affinity to mouse angiotensin-converting enzyme 2 (mACE2), allowing the mice highly susceptible to SARS-CoV-2 (B.1.351) infection. Our work suggests that SARS-CoV-2 (B.1.351) expands the host range and therefore increases its transmission route without adapted mutation. As the wild house mice live with human populations quite closely, this possible transmission route could be potentially risky. In addition, because SARS-CoV-2 (B.1.351) is one of the major epidemic strains and the mACE2 in laboratory-used mice is naturally expressed and regulated, the SARS-CoV-2 (B.1.351)/mice could be a much convenient animal model system to study COVID-19 pathogenesis and evaluate antiviral inhibitors and vaccines.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , COVID-19/transmission , Host-Pathogen Interactions/genetics , Receptors, Virus/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Angiotensin-Converting Enzyme 2/immunology , Animals , COVID-19/immunology , COVID-19/virology , Cytokines/genetics , Cytokines/immunology , Disease Models, Animal , Gene Expression , HEK293 Cells , Host-Pathogen Interactions/immunology , Humans , Lung/pathology , Lung/virology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Protein Binding , Protein Domains , Receptors, Virus/immunology , SARS-CoV-2/classification , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/immunology , Virus Replication
5.
Cell Rep ; 38(3): 110256, 2022 01 18.
Article in English | MEDLINE | ID: covidwho-1588136

ABSTRACT

Inoculation against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is ongoing worldwide. However, the emergence of SARS-CoV-2 variants could cause immune evasion. We developed a bivalent nanoparticle vaccine that displays the receptor binding domains (RBDs) of the D614G and B.1.351 strains. With a prime-boost or a single-dose strategy, this vaccine elicits a robust neutralizing antibody and full protection against infection with the authentic D614G or B.1.351 strain in human angiotensin-converting enzyme 2 transgene mice. Interestingly, 8 months after inoculation with the D614G-specific vaccine, a new boost with this bivalent vaccine potently elicits cross-neutralizing antibodies for SARS-CoV-2 variants in rhesus macaques. We suggest that the D614G/B.1.351 bivalent vaccine could be used as an initial single dose or a sequential enforcement dose to prevent infection with SARS-CoV-2 and its variants.


Subject(s)
COVID-19/prevention & control , Cross Protection , SARS-CoV-2/immunology , Vaccines, Combined/therapeutic use , Animals , CHO Cells , COVID-19 Vaccines/chemical synthesis , COVID-19 Vaccines/immunology , COVID-19 Vaccines/therapeutic use , Chlorocebus aethiops , Cricetulus , Cross Protection/immunology , Female , HEK293 Cells , Humans , Macaca mulatta , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Transgenic , Nanoparticles , Vaccination/methods , Vaccines, Combined/chemical synthesis , Vaccines, Combined/immunology , Vero Cells
8.
mBio ; 12(1)2021 01 19.
Article in English | MEDLINE | ID: covidwho-1066818

ABSTRACT

The etiologic agent of COVID-19 is highly contagious and has caused a severe global pandemic. Until now, there has been no simple and reliable system available in a lower-biosafety-grade laboratory for SARS-CoV-2 virologic research and inhibitor screening. In this study, we reported a replicon system which consists of four plasmids expressing the required segments of SARS-CoV-2. Our study revealed that the features for viral RNA synthesis and responses to antivirus drugs of the replicon are similar to those of wild-type viruses. Further analysis indicated that ORF6 provided potent in trans stimulation of the viral replication. Some viral variations, such as 5'UTR-C241T and ORF8-(T28144C) L84S mutation, also exhibit their different impact upon viral replication. Besides, the screening of clinically used drugs identified that several tyrosine kinase inhibitors and DNA-Top II inhibitors potently inhibit the replicon, as well as authentic SARS-CoV-2 viruses. Collectively, this replicon system provides a biosafety-worry-free platform for studying SARS-CoV-2 virology, monitoring the functional impact of viral mutations, and developing viral inhibitors.IMPORTANCE COVID-19 has caused a severe global pandemic. Until now, there has been no simple and reliable system available in a lower-biosafety-grade laboratory for SARS-CoV-2 virologic research and inhibitor screening. We reported a replicon system which consists of four ordinary plasmids expressing the required segments of SARS-CoV-2. Using the replicon system, we developed three application scenarios: (i) to identify the effects of viral proteins on virus replication, (ii) to identify the effects of mutations on viral replication during viral epidemics, and (iii) to perform high-throughput screening of antiviral drugs. Collectively, this replicon system would be useful for virologists to study SARS-CoV-2 virology, for epidemiologists to monitor virus mutations, and for industry to develop antiviral drugs.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/virology , RNA, Viral/biosynthesis , Replicon/drug effects , SARS-CoV-2/drug effects , SARS-CoV-2/genetics , Drug Evaluation, Preclinical/methods , Female , Genetic Engineering , HEK293 Cells , High-Throughput Screening Assays , Humans , Inhibitory Concentration 50 , Mutation , Pandemics , RNA, Viral/genetics , Replicon/genetics , SARS-CoV-2/metabolism , Virus Replication/drug effects
9.
Immunity ; 53(6): 1315-1330.e9, 2020 12 15.
Article in English | MEDLINE | ID: covidwho-967948

ABSTRACT

Various vaccine strategies have been proposed in response to the global COVID-19 pandemic, each with unique strategies for eliciting immune responses. Here, we developed nanoparticle vaccines by covalently conjugating the self-assembled 24-mer ferritin to the receptor binding domain (RBD) and/or heptad repeat (HR) subunits of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) spike (S) protein. Compared to monomer vaccines, nanoparticle vaccines elicited more robust neutralizing antibodies and cellular immune responses. RBD and RBD-HR nanoparticle vaccinated hACE2 transgenic mice vaccinated with RBD and/or RBD-HR nanoparticles exhibited reduced viral load in the lungs after SARS-CoV-2 challenge. RBD-HR nanoparticle vaccines also promoted neutralizing antibodies and cellular immune responses against other coronaviruses. The nanoparticle vaccination of rhesus macaques induced neutralizing antibodies, and T and B cell responses prior to boost immunization; these responses persisted for more than three months. RBD- and HR-based nanoparticles thus present a promising vaccination approach against SARS-CoV-2 and other coronaviruses.


Subject(s)
Bacterial Proteins/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , Ferritins/immunology , Helicobacter pylori/metabolism , Recombinant Fusion Proteins/immunology , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/immunology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Neutralizing/metabolism , Antibodies, Viral/metabolism , Bacterial Proteins/chemistry , COVID-19 Vaccines/chemistry , Ferritins/chemistry , Humans , Macaca mulatta , Mice , Mice, Inbred BALB C , Nanoparticles/chemistry , Pandemics , Protein Binding , Spike Glycoprotein, Coronavirus/chemistry , Vaccination
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