Virus-like particles (VLPs) are self-assembled particles of viral proteins that are structurally similar to viruses, but do not contain viral genetic material and are therefore not infectious. The introduction of VLP into the body triggers immune responses, but animals do not show any symptoms of the vaccinated virus, providing a high level of safety. BioVenic provides development services for virus-like particle (VLP) veterinary vaccines, and depending on the complexity of the VLP. We have established a variety of expression platforms, including bacterial, yeast, insect cell, plant or mammalian cell lines.
Fig.1 Schematic diagram of VLP preparation.1
Our Services
BioVenic provides end-to-end services and assists you in completing virus-like particle (VLP) veterinary vaccine development. The following section will provide a brief overview of our service offerings.
Expression Vector Construction
Expression vector construction is of vital importance in virus-like particle veterinary vaccine development for expressing viral capsid proteins in host cells. BioVenic offers vector construction services designed to help you construct specialized vectors of your target gene expression. Here are the detailed procedures.
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Cloning Target Gene
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Clone the target gene from its source into a vector of your choice.
Perform sequence amplification, enzymatic cleavage, and ligation steps.
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Vector Modification
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Insert appropriate promoters and activators into the vector to ensure proper expression of your target gene in the host cell.
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Vector Amplification
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Amplify the constructed expression vector.
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Plasmid Purification
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Obtain pure plasmid DNA from the amplified vector using plasmid purification methods.
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Host Cell Transfer
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Transfer the purified plasmid DNA into host cells to achieve expression of your target gene.
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Transformation
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Perform transformation reactions involving cells without vectors, vectors without inserts, pure inserts, successfully ligated vectors, and inserts.
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Screening
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Offer screening services to identify clones containing the correct insert, ensuring the production of high-quality finished products.
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VLP Expression
Since the four-level structure of viral coat proteins may differ in different expression systems, it is necessary to select the appropriate expression system according to the structural properties of different proteins. In addition, choosing the right expression system is also the core factor to ensure the post-translational modification of the protein. BioVenic offers a variety of VLP expression systems to assist your virus-like particle veterinary vaccine development by fulfilling your specific research requirements.
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Expression Systems
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Advantages
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Limitations
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Bacteria
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High-level expression.
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Cost-effective.
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Simple culture conditions.
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Easy manipulation.
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Low immunogenicity.
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Endotoxin contamination risk.
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Limited ability for post-translational modifications.
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Inability to create disulfide bonds.
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Easy to generate inclusion bodies.
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Yeast
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Low cost.
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No endotoxin contamination.
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High-density fermentation.
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Support most protein folding.
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Non-appropriate protein glycosylation.
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High mannose modification.
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Risk of incorrect folding and assembly.
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Insect Cells
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Carry and deliver large amounts of DNA.
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High protein expression.
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Support for post-translational modification of eukaryotic proteins.
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Proper protein folding and assembly.
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Difficult to scale up.
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High production cost.
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Limited to high mannose glycoprotein modification.
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Baculovirus contamination.
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Mammalian Cells
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Producing cells closer to the natural host.
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Appropriate post-translational modifications.
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Proper assembly of VLPs.
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High cost.
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Large-scale production facility required.
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Long expression time.
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Low productivity.
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Animal-derived virus contamination risk.
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Plant Cells
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Ability to scale up.
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Low cost.
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Highly expression.
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Correct folding and assembly.
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No animal-derived virus contamination.
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Technical and regulatory issues.
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Low yields per unit of land area.
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VLP Purification
VLPs expressed through genetic engineering techniques have different sizes, morphologies and are unstable due to different structures and properties of proteins, which need to be purified. After completing the expression of VLP, BioVenic also provides VLP purification services, through multi-step purification operations, to obtain a more stable quality of VLP, so that the development of your veterinary vaccines more smoothly.
Cell Lysis
VLP produced in non-secretory expression systems requires the selection of appropriate cell lysis methods, such as the lysis of bacterial and plant cells. BioVenic offers processing means for mechanical fragmentation, including high-pressure homogenizer fragmentation, ultrasonic fragmentation, abrasive milling, repeated freezing and thawing, and the addition of bacterial fragmentation enzymes. Mammalian cells and insect cells are secreted expression systems, and a washing the cells with washing buffer is sufficient for lysis.
Clarification and Concentration of Lysate
The clarification and concentration of the lysate are crucial steps for effectively separating and concentrating target components, thereby enhancing the efficiency of downstream processes. BioVenic employs polyethylene glycol precipitation to induce the separation of proteins and other impurities from the lysate. Additionally, semi-permeable membrane services selectively retain the target molecules, further concentrating the desired components through ultrafiltration. Furthermore, our provided ammonium sulfate precipitation services facilitate protein precipitation, aiding in the removal of impurities.
Fine Purification
Fine purification is crucial in the overall purification process. Using gradient centrifugation or chromatographic methods such as gel filtration chromatography, affinity chromatography or ion exchange chromatography, impurities including residual host proteins, nucleic acids, etc., must be further removed in this step to bring them below the specified upper limit.
Sterilization and Filtration
Sterilization and filtration in centrifuge tubes with minimal retention volume is recommended to minimize sample loss, and PVDF membrane is utilized in this service due to its convenient usage, high sample recovery rate, and excellent reproducibility, providing greater assistance to your development efforts.
VLP Characterization
Due to the lack of secondary capsid proteins, nucleic acids and other components in the self-assembly of viruses, VLP is often polymorphic. Therefore, physicochemical and biological properties of VLP are important evaluation indexes for virus-like particle veterinary vaccine development, which directly affect the function, efficacy and stability of the products. BioVenic provides VLP characterization services to analyze the morphology, structure, size and distribution to provide your vaccines with stable quality.
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Transmission Electron Microscope
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Determine the external morphology and particle size of VLP.
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SDS-PAGE and Western Blotting
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SDS-PAGE to determine VLP size and purity and Western blotting to determine the presence of specific proteins.
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Mass Spectrometry
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Determine the sequence of proteins in VLP samples.
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Dynamic Light Scattering
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Measure the size distribution of VLP particles and the dynamic properties of particles, including the diffusion coefficient of particles and the particle concentration.
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Virus-like Particle Veterinary Vaccine Development Services
In the process of developing veterinary VLP vaccines, BioVenic offers comprehensive solutions encompassing various key services.
Through a series of in vitro and in vivo assays, we assist in evaluating the efficacy, safety, and immunogenicity of your veterinary VLP vaccine in a biological environment. These services validate its performance both in vitro and in the actual biological context, providing crucial data for a deep understanding of vaccine characteristics.
Considering the immunogenicity of VLPs, our commitment extends to providing optimal formulations for your veterinary vaccine. Through services such as adjuvant development, we aim to enhance the immunological efficiency and practicality of your veterinary VLP vaccine.
We implement stringent quality control measures to ensure the consistency and quality of your veterinary VLP vaccine during the whole development process.
Why Choose Us?
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A variety of VLP expression platforms.
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Careful and considerate VLP purification services.
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Full range of VLP characterization services to ensure the quality of your vaccine development.
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Virus-like particle vaccine development for protecting livestock, poultry, companion animals, aquaculture species and more.
Virus-like particle veterinary vaccines have a wide range of applications in the prevention and control of animal diseases and are of great significance in maintaining animal health and improving agricultural productivity. BioVenic provides full process development services for virus-like particle veterinary vaccines, and we will help you develop your veterinary vaccines with rich experience and professional staff. Contact us now to help the development of animal health!
References
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Kheirvari, Milad; et al. "Virus-like Particle Vaccines and Platforms for Vaccine Development." Viruses 15.5 (2023): 1109.
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Le, Dinh To, and Kristian M. Müller. "In vitro assembly of virus-like particles and their applications." Life 11.4 (2021): 334.
