Effects of downstream processing on structural integrity and immunogenicity in the manufacture of papillomavirus type 16 L1 virus-like particles

2012 ◽  
Vol 17 (4) ◽  
pp. 755-763 ◽  
Author(s):  
Don Yong Chang ◽  
Hyoung Jin Kim ◽  
Hong-Jin Kim
Keyword(s):  
Structural Integrity ◽  
Downstream Processing ◽  
Virus Like Particles

Downstream processing of virus-like particles: Single-stage and multi-stage aqueous two-phase extraction

2015 ◽  
Vol 1383 ◽  
pp. 35-46 ◽  
Author(s):  
Christopher Ladd Effio ◽  
Lukas Wenger ◽  
Ozan Ötes ◽  
Stefan A. Oelmeier ◽  
Richard Kneusel ◽  
...  
Keyword(s):  
Downstream Processing ◽  
Single Stage ◽  
Phase Extraction ◽  
Two Phase ◽  
Virus Like Particles ◽  
Multi Stage ◽  
Aqueous Two Phase Extraction

Characterization and downstream processing of HIV-1 core and virus-like-particles produced in serum free medium

2000 ◽  
Vol 26 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Pedro E Cruz ◽  
Cristina C Peixoto ◽  
Kathleen Devos ◽  
José L Moreira ◽  
Eric Saman ◽  
...  
Keyword(s):  
Downstream Processing ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Virus Like Particles ◽  
Hiv 1

scholarly journals Minimal system for assembly of SARS-CoV-2 virus like particles

2020 ◽  
Author(s):  
Heather Swann ◽  
Abhimanyu Sharma ◽  
Benjamin Preece ◽  
Abby Peterson ◽  
Crystal Eldridge ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Structural Integrity ◽  
Vaccine Development ◽  
Viral Proteins ◽  
Characteristic Size ◽  
Minimal System ◽  
Ambient Conditions ◽  
Virus Like Particles ◽  
Force Microscopy ◽  
Atomic Force

AbstractSARS-CoV-2 virus is the causative agent of COVID-19. Here we demonstrate that non-infectious SARS-CoV-2 virus like particles (VLPs) can be assembled by co-expressing the viral proteins S, M and E in mammalian cells. The assembled SARS-CoV-2 VLPs possess S protein spikes on particle exterior, making them ideal for vaccine development. The particles range in shape from spherical to elongated with a characteristic size of 129 ± 32 nm. We further show that SARS-CoV-2 VLPs dried in ambient conditions can retain their structural integrity upon repeated scans with Atomic Force Microscopy up to a peak force of 1 nN.

Membrane‐Based Approach for the Downstream Processing of Influenza Virus‐Like Particles

2019 ◽  
Vol 14 (8) ◽  
pp. 1800570 ◽  
Author(s):  
Sofia B. Carvalho ◽  
Ricardo J. S. Silva ◽  
Mafalda G. Moleirinho ◽  
Bárbara Cunha ◽  
Ana S. Moreira ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Downstream Processing ◽  
Virus Like Particles

scholarly journals Modulation of Thiol-Disulfide Oxidoreductases for Increased Production of Disulfide-Bond-Containing Proteins in Bacillus subtilis

2008 ◽  
Vol 74 (24) ◽  
pp. 7536-7545 ◽  
Author(s):  
Thijs R. H. M. Kouwen ◽  
Jean-Yves F. Dubois ◽  
Roland Freudl ◽  
Wim J. Quax ◽  
Jan Maarten van Dijl
Keyword(s):  
Bacillus Subtilis ◽  
Disulfide Bond ◽  
Disulfide Bonds ◽  
Structural Integrity ◽  
Downstream Processing ◽  
Cell Factory ◽  
Biotechnological Production ◽  
Redox Active ◽  
Model Protein

ABSTRACT Disulfide bonds are important for the correct folding, structural integrity, and activity of many biotechnologically relevant proteins. For synthesis and subsequent secretion of these proteins in bacteria, such as the well-known “cell factory” Bacillus subtilis, it is often the correct formation of disulfide bonds that is the greatest bottleneck. Degradation of inefficiently or incorrectly oxidized proteins and the requirement for costly and time-consuming reduction and oxidation steps in the downstream processing of the proteins still are major limitations for full exploitation of B. subtilis for biopharmaceutical production. Therefore, the present study was aimed at developing a novel in vivo strategy for improved production of secreted disulfide-bond-containing proteins. Three approaches were tested: depletion of the major cytoplasmic reductase TrxA; introduction of the heterologous oxidase DsbA from Staphylococcus carnosus; and addition of redox-active compounds to the growth medium. As shown using the disulfide-bond-containing molecule Escherichia coli PhoA as a model protein, combined use of these three approaches resulted in secretion of amounts of active PhoA that were ∼3.5-fold larger than the amounts secreted by the parental strain B. subtilis 168. Our findings indicate that Bacillus strains with improved oxidizing properties can be engineered for biotechnological production of heterologous high-value proteins containing disulfide bonds.

scholarly journals Design of Alphavirus Virus-Like Particles Presenting Circumsporozoite Junctional Epitopes That Elicit Protection against Malaria

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 272
Author(s):  
Joseph R. Francica ◽  
Wei Shi ◽  
Gwo-Yu Chuang ◽  
Steven J. Chen ◽  
Lais Da Silva Pereira ◽  
...  
Keyword(s):  
Malaria Vaccine ◽  
Structural Integrity ◽  
Keyhole Limpet Hemocyanin ◽  
Effective Vaccine ◽  
Virus Like Particles ◽  
Human Antibodies ◽  
Negative Stain ◽  
Serum Titer ◽  
Negative Stain Electron Microscopy ◽  
Genetic Fusion

The most advanced malaria vaccine, RTS,S, includes the central repeat and C-terminal domains of the Plasmodium falciparum circumsporozoite protein (PfCSP). We have recently isolated human antibodies that target the junctional region between the N-terminal and repeat domains that are not included in RTS,S. Due to the fact that these antibodies protect against malaria challenge in mice, their epitopes could be effective vaccine targets. Here, we developed immunogens displaying PfCSP junctional epitopes by genetic fusion to either the N-terminus or B domain loop of the E2 protein from chikungunya (CHIK) alphavirus and produced CHIK virus-like particles (CHIK-VLPs). The structural integrity of these junctional-epitope–CHIK-VLP immunogens was confirmed by negative-stain electron microscopy. Immunization of these CHIK-VLP immunogens reduced parasite liver load by up to 95% in a mouse model of malaria infection and elicited better protection than when displayed on keyhole limpet hemocyanin, a commonly used immunogenic carrier. Protection correlated with PfCSP serum titer. Of note, different junctional sequences elicited qualitatively different reactivities to overlapping PfCSP peptides. Overall, these results show that the junctional epitopes of PfCSP can induce protective responses when displayed on CHIK-VLP immunogens and provide a basis for the development of a next generation malaria vaccine to expand the breadth of anti-PfCSP immunity.

scholarly journals Minimal system for assembly of SARS-CoV-2 virus like particles

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Heather Swann ◽  
Abhimanyu Sharma ◽  
Benjamin Preece ◽  
Abby Peterson ◽  
Crystal Eldridge ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Structural Integrity ◽  
Vaccine Development ◽  
Viral Proteins ◽  
Characteristic Size ◽  
Minimal System ◽  
Ambient Conditions ◽  
Virus Like Particles ◽  
Force Microscopy ◽  
Atomic Force

AbstractSARS-CoV-2 virus is the causative agent of COVID-19. Here we demonstrate that non-infectious SARS-CoV-2 virus like particles (VLPs) can be assembled by co-expressing the viral proteins S, M and E in mammalian cells. The assembled SARS-CoV-2 VLPs possess S protein spikes on particle exterior, making them ideal for vaccine development. The particles range in shape from spherical to elongated with a characteristic size of 129 ± 32 nm. We further show that SARS-CoV-2 VLPs dried in ambient conditions can retain their structural integrity upon repeated scans with Atomic Force Microscopy up to a peak force of 1 nN.

scholarly journals Assembly of Double-Shelled, Virus-Like Particles in Transgenic Rice Plants Expressing Two Major Structural Proteins of Rice Dwarf Virus

2000 ◽  
Vol 74 (20) ◽  
pp. 9808-9810 ◽  
Author(s):  
Honghong Zheng ◽  
Li Yu ◽  
Chunhong Wei ◽  
Dongwei Hu ◽  
Yunping Shen ◽  
...  
Keyword(s):  
Transgenic Rice ◽  
Structural Integrity ◽  
Core Protein ◽  
Dwarf Virus ◽  
Structural Proteins ◽  
Rice Dwarf Virus ◽  
Virus Like Particles ◽  
Rice Plants ◽  
Transgenic Rice Plants ◽  
Core Proteins

ABSTRACT Rice dwarf virus (RDV) is a double-shelled particle that contains a major capsid protein (P8), a major core protein (P3), several minor core proteins, and viral genomic double-stranded RNA. Coexpression of P8 and P3 in transgenic rice plants resulted in formation of double-shelled, virus-like particles (VLPs) similar to the authentic RDV particles. The VLPs were not detected in transgenic rice plant cells expressing P8 alone. This in vivo result suggests that P8 interacted with P3 and that these two proteins provide the structural integrity required for the formation of VLPs in rice cells independently of other structural proteins, nonstructural proteins, or viral genomic double-stranded RNAs.

Downstream processing of virus, virus-like particles and nanoparticulate inclusion bodies to be used as gene delivery vehicles for human gene therapy applications

2021 ◽  
Author(s):  
Moataz Dowaidar
Keyword(s):  
Environmental Sustainability ◽  
Inclusion Bodies ◽  
Culture Media ◽  
Downstream Processing ◽  
Economic Feasibility ◽  
Two Phase ◽  
Affinity Ligands ◽  
Virus Like Particles ◽  
Aqueous Two Phase Systems ◽  
Phase Systems

Design and analyze future affinity ligands such as antibodies, aptamers, metal affinity, peptides, triazine dyes, and red blood cell carriers to increase monolithic chromatography selectivity and two-phase affinity-aqueous systems. Monolithic chromatography systems may be constructed and optimized by examining viruses, virus-like particles, and nanoparticulate inclusion bodies from difficult culture media. Different chromatographic characteristics such as monolithic supports, active monolith groups, binding and elution buffers, elution gradients, column equilibrium volumes, and regeneration should be investigated with the aim of optimizing monolithic chromatography separation and recovery. To develop and optimize aqueous two-phase systems, several different parameters need to be investigated and compared, such as polymer type and concentration, salt solution, surfactants and ions, polymer molecular weight, ion nature and ionic strength, present affinity ligands, volumetric ratio, temperature, pH, and sample load, to name a few.Several relevant biological models, such as Newcastle disease (NDV), herpes (HPr), or viral vectors bluetongue (BTV), can be employed to establish different patterns and predict the generalized mechanistic process of enhanced purification systems. Because optimal systems are intended to be deployed at the industrial level, a comparison of typical downstream processing and alternatives in terms of recovery, technological advantages, economic feasibility, and environmental sustainability is needed. Cell separation, viral concentration and viral purification may all be reduced to one step utilizing integrated chromatography platforms on monolith supports and aqueous two-phase systems. In addition, the efficiency of separation and purification yields achieved after these integrated systems are predicted to be substantially higher than those produced in conventional procedures. As a result, the benefits of these alternative and cutting-edge technologies are predicted to contribute to more efficient, long-term, and cost-effective downstream processing of virus-like particles.

Electron Beam Damage of Biomolecules Assessed by Energy Loss Spectroscopy

1978 ◽  
Vol 36 (3) ◽  
pp. 61-69
Author(s):  
M. Isaacson ◽  
M.L. Collins ◽  
M. Listvan
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Structural Integrity ◽  
Analytical Electron Microscopy ◽  
High Dose ◽  
Dose Rates ◽  
Special Cases ◽  
Analytical Electron ◽  
Atom Migration ◽  
Beam Damage

Over the past five years it has become evident that radiation damage provides the fundamental limit to the study of blomolecular structure by electron microscopy. In some special cases structural determinations at very low doses can be achieved through superposition techniques to study periodic (Unwin & Henderson, 1975) and nonperiodic (Saxton & Frank, 1977) specimens. In addition, protection methods such as glucose embedding (Unwin & Henderson, 1975) and maintenance of specimen hydration at low temperatures (Taylor & Glaeser, 1976) have also shown promise. Despite these successes, the basic nature of radiation damage in the electron microscope is far from clear. In general we cannot predict exactly how different structures will behave during electron Irradiation at high dose rates. Moreover, with the rapid rise of analytical electron microscopy over the last few years, nvicroscopists are becoming concerned with questions of compositional as well as structural integrity. It is important to measure changes in elemental composition arising from atom migration in or loss from the specimen as a result of electron bombardment.

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