A core-shell structured COVID-19 mRNA vaccine with favorable biodistribution pattern and promising immunity

AbstractAlthough inoculation of COVID-19 vaccines has rolled out globally, there is still a critical need for safe and effective vaccines to ensure fair and equitable supply for all countries. Here, we report on the development of a highly efficacious mRNA vaccine, SW0123 that is composed of sequence-modified mRNA encoding the full-length SARS-CoV-2 Spike protein packaged in core–shell structured lipopolyplex (LPP) nanoparticles. SW0123 is easy to produce using a large-scale microfluidics-based apparatus. The unique core–shell structured nanoparticle facilitates vaccine uptake and demonstrates a high colloidal stability, and a desirable biodistribution pattern with low liver targeting effect upon intramuscular administration. Extensive evaluations in mice and nonhuman primates revealed strong immunogenicity of SW0123, represented by induction of Th1-polarized T cell responses and high levels of antibodies that were capable of neutralizing not only the wild-type SARS-CoV-2, but also a panel of variants including D614G and N501Y variants. In addition, SW0123 conferred effective protection in both mice and non-human primates upon SARS-CoV-2 challenge. Taken together, SW0123 is a promising vaccine candidate that holds prospects for further evaluation in humans.

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Protective Immunity to Pseudomonas aeruginosa Induced with a Capsid-Modified Adenovirus Expressing P. aeruginosa OprF

Journal of Virology ◽

10.1128/jvi.01246-07 ◽

2007 ◽

Vol 81 (24) ◽

pp. 13801-13808 ◽

Cited By ~ 41

Author(s):

Stefan Worgall ◽

Anja Krause ◽

JianPing Qiu ◽

Ju Joh ◽

Neil R. Hackett ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Protective Immunity ◽

Vaccine Candidate ◽

Wild Type ◽

Cell Responses ◽

Rgd Sequence ◽

Hexon Protein ◽

Repeat Administration ◽

Antigen Presenting ◽

Fiber Gene

ABSTRACT This study focuses on the development of a new clinical vaccine candidate (AdOprF.RGD.Epi8) against Pseudomonas aeruginosa using an E1− E3− adenovirus (Ad) vector expressing OprF (AdOprF.RGD.Epi8) and modifications of the Ad genome providing two capsid changes: (i) modification of the Ad hexon gene to incorporate an immune-dominant OprF epitope (Epi8) into loop 1 of the hexon, enabling repeat administration to boost the anti-OprF immune response, and (ii) modification of the fiber gene to incorporate an integrin-binding RGD sequence to enhance gene delivery to antigen-presenting cells. Western analysis confirmed that AdOprF.RGD.Epi8 expresses OprF, contains Epi8 in the hexon protein, and enhances gene transfer to dendritic cells compared to AdOprF, a comparable Ad vector expressing OprF with an unmodified capsid. Intramuscular immunization of C57BL/6 mice with AdOprF.RGD.Epi8 resulted in the generation of anti-OprF antibodies at comparable levels to those induced following immunization with AdOprF, but immunization with AdOprF.RGD.Epi8 was associated with increased CD4 and CD8 gamma interferon T-cell responses against OprF as well as increased survival against lethal pulmonary challenge with agar-encapsulated P. aeruginosa. Importantly, repeat administration of AdOprF.RGD.Epi8 resulted in boosting of the humoral anti-OprF response as well as increased protection, whereas no boosting could be achieved with repeat administration of AdOprF. This suggests that the capsid-modified AdOprF.RGD.Epi8 vector is a more effective immunogen compared to a comparable wild-type Ad capsid, making it a good candidate for an anti-P. aeruginosa vaccine.

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mRNA-based SARS-CoV-2 vaccine candidate CVnCoV induces high levels of virus-neutralising antibodies and mediates protection in rodents

npj Vaccines ◽

10.1038/s41541-021-00311-w ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Susanne Rauch ◽

Nicole Roth ◽

Kim Schwendt ◽

Mariola Fotin-Mleczek ◽

Stefan O. Mueller ◽

...

Keyword(s):

Viral Replication ◽

Vaccine Candidate ◽

Wild Type ◽

Neutralising Antibodies ◽

Cell Responses ◽

Naturally Occurring ◽

Safe Vaccine ◽

Suboptimal Dose ◽

Humoral Responses ◽

Clinical Candidate

AbstractmRNA technologies have recently proven clinical efficacy against coronavirus disease 2019 and are among the most promising technologies to address the current pandemic. Here, we show preclinical data for our clinical candidate CVnCoV, a lipid nanoparticle-encapsulated mRNA vaccine that encodes full-length, pre-fusion stabilised severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spike protein. In contrast to previously published approaches, CVnCoV is exclusively composed of naturally occurring nucleotides. Immunisation with CVnCoV induced strong humoral responses with high titres of virus-neutralising antibodies and robust T-cell responses. CVnCoV vaccination protected hamsters from challenge with wild-type SARS-CoV-2, demonstrated by the absence of viral replication in the lungs. Hamsters vaccinated with a suboptimal dose of CVnCoV leading to breakthrough viral replication exhibited no evidence of vaccine-enhanced disease. Overall, data presented here provide evidence that CVnCoV represents a potent and safe vaccine candidate against SARS-CoV-2.

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An Effective Live Vaccine Strain Of Trypanosoma Cruzi Prevents Chagas Disease In The Mouse Model

10.21203/rs.3.rs-92241/v1 ◽

2020 ◽

Author(s):

Bijay Jha ◽

Sanjay Varikuti ◽

Nicholas Bishop ◽

Gregory dos Santos ◽

Jacquelyn McDonald ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Vaccine Candidate ◽

Etiologic Agent ◽

Live Vaccine ◽

Parasite Line ◽

Wild Type ◽

Knock Out ◽

Cell Responses ◽

Deficient Mice

Abstract Trypanosoma cruzi is the etiologic agent of Chagas disease for which there are no prophylactic vaccines. Cyclophilin 19 is a secreted cis-trans peptidyl isomerase expressed in all life stages of Trypanosoma cruzi, which in the insect stage leads to the inactivation of insect anti-parasitic peptides and parasite transformation and in intracellular amastigotes participates in generating ROS enhancing parasite growth. We have generated a parasite knock-out mutant of Cyp19 which fails to replicate in cell culture or in mice indicating that lack of Cyp19 is critical for infectivity. Knock-out parasites fail to replicate in or cause clinical disease in immune-deficient mice further validating their lack of virulence. Repeated inoculation of knock-out parasites into immuno-competent mice elicits parasite-specific antibodies and T-cell responses. Challenge of immunized mice with wild-type parasites is 100% effective at preventing disease. These results indicate that the knock-out parasite line is a live vaccine candidate for Chagas disease.

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An adjuvanted subunit SARS-CoV-2 spike protein vaccine provides protection against Covid-19 infection and transmission

10.21203/rs.3.rs-902649/v1 ◽

2021 ◽

Author(s):

Kairat Tabynov ◽

Nurkeldi Turebekov ◽

Meruert Babayeva ◽

Gleb Fomin ◽

Toktasyn Yerubaev ◽

...

Keyword(s):

T Cell ◽

Neutralizing Antibodies ◽

Vaccine Candidate ◽

T Cell Responses ◽

Spike Protein ◽

Effective Vaccine ◽

Protein Vaccine ◽

Wild Type ◽

Cell Responses ◽

Ongoing Development

Abstract Recombinant protein approaches offer major promise for safe and effective vaccine prevention of SARS-CoV-2 infection. We developed a recombinant spike protein vaccine (called NARUVAX-C19) and characterized its ability when formulated with a nanoemulsion adjuvant to induce anti-spike antibody and T-cell responses and provide protection including against viral transmission in rodent. In mice, NARUVAX-C19 vaccine administered intramuscularly twice at 21-day interval elicited balanced Th1/Th2 humoral and T-cell responses with high titers of neutralizing antibodies against wild-type (D614G) and delta (B.1.617.2) variants. In Syrian hamsters, NARUVAX-C19 provided complete protection against wild-type (D614G) infection and prevented its transmission to naïve animals placed in the same cage as challenged animals. The results contrasted with only weak protection seen with a monomeric spike receptor binding domain (RBD) vaccine even when formulated with the same adjuvant. These encouraging results warrant ongoing development of this Covid-19 vaccine candidate.

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Immunization with RBD-P2 and N protects against SARS-CoV-2 in nonhuman primates

Science Advances ◽

10.1126/sciadv.abg7156 ◽

2021 ◽

Vol 7 (22) ◽

pp. eabg7156

Author(s):

So-Hee Hong ◽

Hanseul Oh ◽

Yong Wook Park ◽

Hye Won Kwak ◽

Eun Young Oh ◽

...

Keyword(s):

Nucleocapsid Protein ◽

Nonhuman Primates ◽

Vaccine Candidate ◽

Statistical Significance ◽

Neutralizing Antibody ◽

Spike Protein ◽

Vaccine Candidates ◽

Cell Responses ◽

Antibody Levels ◽

Further Development

Since the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), various vaccines are being developed, with most vaccine candidates focusing on the viral spike protein. Here, we developed a previously unknown subunit vaccine comprising the receptor binding domain (RBD) of the spike protein fused with the tetanus toxoid epitope P2 (RBD-P2) and tested its efficacy in rodents and nonhuman primates (NHPs). We also investigated whether the SARS-CoV-2 nucleocapsid protein (N) could increase vaccine efficacy. Immunization with N and RBD-P2 (RBDP2/N) + alum increased T cell responses in mice and neutralizing antibody levels in rats compared with those obtained using RBD-P2 + alum. Furthermore, in NHPs, RBD-P2/N + alum induced slightly faster SARS-CoV-2 clearance than that induced by RBD-P2 + alum, albeit without statistical significance. Our study supports further development of RBD-P2 as a vaccine candidate against SARS-CoV-2. Also, it provides insights regarding the use of N in protein-based vaccines against SARS-CoV-2.

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INTRACISTRONIC MAPPING OF ELECTROPHORETIC SITES IN DROSOPHILA MELANOGASTER: FIDELITY OF INFORMATION TRANSFER BY GENE CONVERSION

Genetics ◽

10.1093/genetics/76.2.289 ◽

1974 ◽

Vol 76 (2) ◽

pp. 289-299

Author(s):

Margaret McCarron ◽

William Gelbart ◽

Arthur Chovnick

Keyword(s):

Drosophila Melanogaster ◽

Information Transfer ◽

Large Scale ◽

Genetic Basis ◽

Xanthine Dehydrogenase ◽

Specific Protein ◽

Wild Type ◽

Electrophoretic Variation ◽

The Stability ◽

Recombination Experiments

ABSTRACT A convenient method is described for the intracistronic mapping of genetic sites responsible for electrophoretic variation of a specific protein in Drosophila melanogaster. A number of wild-type isoalleles of the rosy locus have been isolated which are associated with the production of electrophoretically distinguishable xanthine dehydrogenases. Large-scale recombination experiments were carried out involving null enzyme mutants induced on electrophoretically distinct wild-type isoalleles, the genetic basis for which is followed as a nonselective marker in the cross. Additionally, a large-scale recombination experiment was carried out involving null enzyme rosy mutants induced on the same wild-type isoallele. Examination of the electrophoretic character of crossover and convertant products recovered from the latter experiment revealed that all exhibited the same parental electrophoretic character. In addition to documenting the stability of the xanthine dehydrogenase electrophoretic character, this observation argues against a special mutagenesis hypothesis to explain conversions resulting from allele recombination studies.

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Soluble Spike DNA Vaccine Provides Long-Term Protective Immunity against SARS-CoV-2 in Mice and Nonhuman Primates

Vaccines ◽

10.3390/vaccines9040307 ◽

2021 ◽

Vol 9 (4) ◽

pp. 307

Author(s):

Yong Bok Seo ◽

You Suk Suh ◽

Ji In Ryu ◽

Hwanhee Jang ◽

Hanseul Oh ◽

...

Keyword(s):

T Cell ◽

Nonhuman Primates ◽

Vaccine Candidate ◽

T Cell Responses ◽

Neutralizing Antibody ◽

Dependent Manner ◽

Viral Loads ◽

Cell Responses ◽

Rapid Spread

The unprecedented and rapid spread of SARS-CoV-2 (severe acute respiratory syndrome-coronavirus-2) has motivated the need for a rapidly producible and scalable vaccine. Here, we developed a synthetic soluble SARS-CoV-2 spike (S) DNA-based vaccine candidate, GX-19. In mice, immunization with GX-19 elicited not only S-specific systemic and pulmonary antibody responses but also Th1-biased T cell responses in a dose-dependent manner. GX-19-vaccinated nonhuman primates seroconverted rapidly and exhibited a detectable neutralizing antibody response as well as multifunctional CD4+ and CD8+ T cell responses. Notably, when the immunized nonhuman primates were challenged at 10 weeks after the last vaccination with GX-19, they had reduced viral loads in contrast to non-vaccinated primates as a control. These findings indicate that GX-19 vaccination provides a durable protective immune response and also support further development of GX-19 as a vaccine candidate for SARS-CoV-2.

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A Novel and Efficient High-Yield Method for Preparing Bacterial Ghosts

Toxins ◽

10.3390/toxins13060420 ◽

2021 ◽

Vol 13 (6) ◽

pp. 420

Author(s):

Yi Ma ◽

Liu Cui ◽

Meng Wang ◽

Qiuli Sun ◽

Kaisheng Liu ◽

...

Keyword(s):

Large Scale ◽

Expression System ◽

High Yield ◽

Wild Type ◽

High Quality ◽

Efficient Protection ◽

Bacterial Ghosts ◽

Cell Envelopes ◽

Extracellular Structures ◽

First Time

Bacterial ghosts (BGs) are empty cell envelopes possessing native extracellular structures without a cytoplasm and genetic materials. BGs are proposed to have significant prospects in biomedical research as vaccines or delivery carriers. The applications of BGs are often limited by inefficient bacterial lysis and a low yield. To solve these problems, we compared the lysis efficiency of the wild-type protein E (EW) from phage ΦX174 and the screened mutant protein E (EM) in the Escherichia coli BL21(DE3) strain. The results show that the lysis efficiency mediated by protein EM was improved. The implementation of the pLysS plasmid allowed nearly 100% lysis efficiency, with a high initial cell density as high as OD600 = 2.0, which was higher compared to the commonly used BG preparation method. The results of Western blot analysis and immunofluorescence indicate that the expression level of protein EM was significantly higher than that of the non-pLysS plasmid. High-quality BGs were observed by SEM and TEM. To verify the applicability of this method in other bacteria, the T7 RNA polymerase expression system was successfully constructed in Salmonella enterica (S. Enterica, SE). A pET vector containing EM and pLysS were introduced to obtain high-quality SE ghosts which could provide efficient protection for humans and animals. This paper describes a novel and commonly used method to produce high-quality BGs on a large scale for the first time.

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Large-Scale Synonymous Substitutions in Cucumber Mosaic Virus RNA 3 Facilitate Amino Acid Mutations in the Coat Protein

Journal of Virology ◽

10.1128/jvi.01007-18 ◽

2018 ◽

Vol 92 (22) ◽

Cited By ~ 1

Author(s):

Tomofumi Mochizuki ◽

Rie Ohara ◽

Marilyn J. Roossinck

Keyword(s):

Amino Acid ◽

Secondary Structure ◽

Viral Genome ◽

Large Scale ◽

Viral Rna ◽

Wild Type ◽

Competitive Fitness ◽

Content Type ◽

Synonymous Substitutions ◽

Cp Gene

ABSTRACTThe effect of large-scale synonymous substitutions in a small icosahedral, single-stranded RNA viral genome on virulence, viral titer, and protein evolution were analyzed. The coat protein (CP) gene of the Fny stain of cucumber mosaic virus (CMV) was modified. We created four CP mutants in which all the codons of nine amino acids in the 5′ or 3′ half of the CP gene were replaced by either the most frequently or the least frequently used synonymous codons in monocot plants. When the dicot host (Nicotiana benthamiana) was inoculated with these four CP mutants, viral RNA titers in uninoculated symptomatic leaves decreased, while all mutants eventually showed mosaic symptoms similar to those for the wild type. The codon adaptation index of these four CP mutants against dicot genes was similar to those of the wild-type CP gene, indicating that the reduction of viral RNA titer was due to deleterious changes of the secondary structure of RNAs 3 and 4. When two 5′ mutants were serially passaged inN. benthamiana, viral RNA titers were rapidly restored but competitive fitness remained decreased. Although no nucleic acid changes were observed in the passaged wild-type CMV, one to three amino acid changes were observed in the synonymously mutated CP of each passaged virus, which were involved in recovery of viral RNA titer of 5′ mutants. Thus, we demonstrated that deleterious effects of the large-scale synonymous substitutions in the RNA viral genome facilitated the rapid amino acid mutation(s) in the CP to restore the viral RNA titer.IMPORTANCERecently, it has been known that synonymous substitutions in RNA virus genes affect viral pathogenicity and competitive fitness by alteration of global or local RNA secondary structure of the viral genome. We confirmed that large-scale synonymous substitutions in the CP gene of CMV resulted in decreased viral RNA titer. Importantly, when viral evolution was stimulated by serial-passage inoculation, viral RNA titer was rapidly restored, concurrent with a few amino acid changes in the CP. This novel finding indicates that the deleterious effects of large-scale nucleic acid mutations on viral RNA secondary structure are readily tolerated by structural changes in the CP, demonstrating a novel part of the adaptive evolution of an RNA viral genome. In addition, our experimental system for serial inoculation of large-scale synonymous mutants could uncover a role for new amino acid residues in the viral protein that have not been observed in the wild-type virus strains.

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