Vaccinia Viral Vector Development Service
Creative Biolabs provides a comprehensive suite of services related to vaccinia viral vector development, tailored to meet the diverse needs of our clients.
Background
Acne virus is a member of the poxvirudae family, and is an enveloped virus with a double stranded DNA genome. These viruses replicate in the cytoplasm of mammalian cells because they do not require host replication mechanisms in the nucleus. This characteristic allows poxvirus to replicate in enucleated cells. The acne virus has a large genome, which allows for large insertions (up to 25kb of exogenous DNA) and high-level DNA expression from prokaryotes or eukaryotes due to regulation by the strong acne virus promoter. The stable insertion of exogenous genes into the viral genome allows for effective replication and expression, including appropriate post-translational modifications in infected cells. Although the transduction of viral vectors is brief, the expression level of transgenes is high.
Figure 1 Ideal timeline for evaluation of a novel Modified Vaccinia virus Ankara-based vaccine.1
What is Vaccinia Viral Vector?
Vaccinia viral vector is an attenuated smallpox virus , a virus vector used to deliver exogenous genetic material into cells. In particular, it is a delivery vehicle that inserts new genes into cells. The cells express the inserted genes and begin to produce the proteins that are encoded by the genes. This tool is used for the study of gene function, the production of proteins and immune response, and for the development of vaccines and gene therapies.
Modified Vaccinia Ankara(MVA)Vector
The Modified Vaccinia Ankara (MVA) virus is a highly attenuated strain of vaccinia virus, derived from vaccinia strain Ankara by over 570 passages in chicken embryo fibroblast cells (CEF) with a loss of about 10% of the vaccinia genome. Due to the high safety of the attenuated phenotype, MVA is widely used for clinical research. Moreover, MVA has the ability to deliver antigens in a highly immunogenic way, which makes it a proper vaccine vector.
Types of Vaccinia Viral Vector
Modified Vaccinia Ankara(MVA)Vector
The Modified Vaccinia Ankara (MVA) virus is a highly attenuated strain of vaccinia virus, derived from vaccinia strain Ankara by over 570 passages in chicken embryo fibroblast cells (CEF) with a loss of about 10% of the vaccinia genome. Due to the high safety of the attenuated phenotype, MVA is widely used for clinical research.
NYVAC Vector
The NYVAC vector is a highly attenuated strain of vaccinia virus which was derived from a plaque-cloned isolate of the Copenhagen vaccinia vaccine strain with the deletion of 18 orfs that contain virulence factors and human host range replication proteins. NYVAC cannot replicate in human cells, either.
ALVAC Vector
ALVAC is an attenuated canarypox virus vector which was derived from a plaque-cloned virus of Kanapox. The ALVAC vector is used as a ubiquitous vector for the development of several vaccines for animals (such as horses) and humans.
TROVAC Vector
TROVAC is an attenuated fowlpox virus vector which was derived from a plaque-cloned FP-1 vaccine strain. Just like ALVAC, TROVAC do not grow in mammalian cells.
Others Vectors
The PANVAC system comprises recombinant vaccinia and fowlpox viruses, carrying the tumor-associated antigens epithelial MUC-1, the carcinomebryonic antigen (CEA) as well as T cell stimulatory molecules.
Core Services at Creative Biolabs
At Creative Biolabs, our process integrates meticulous vector design, precise genetic engineering facilitated by homologous recombination, and strict purification and quality control measures. These carefully designed carriers are powerful tools for preventive immunization and therapeutic interventions. Their cytoplasmic replication mechanism, coupled with their enormous cloning ability, provides significant safety advantages over many other viral vector systems. Our comprehensive services cover customized vector design for antigen expression in vaccine applications to the creation of efficient, tumor selective oncolytic viruses, all aimed at significantly advancing biomedical research and accelerating the discovery and development of new therapies.
- Custom Vaccinia Vector Construction: From gene synthesis to final vector delivery.
- Oncolytic Virus Engineering: Specialized services for developing tumor-selective oncolytic VACV.
- Vector Attenuation & Safety Modification: Engineering replication-deficient or highly attenuated vectors like MVA.
- Large-Scale Viral Stock Production: High-titer production for preclinical studies.
The Workflow of Our Vaccinia Viral Vector Development Service
Our service is a detailed and multi-step workflow dedicated to producing high quality, customized virus vectors.
Project Consultation and Design: In-depth consultation with clients to get a good understanding of their needs. This can include target genes, expression needs, expected applications, etc. Our team of scientific experts has then designed a customized vector strategy, which includes choosing an appropriate VACV strain (Western Reserve, Copenhagen, MVA), selecting the optimal insertion site and designing an expression cassette.
Plasmid Construction: The target gene is codon optimized and synthesized to allow for high expression in target host. The gene is then cloned into a transfer plasmid, which also contains flanking sequences homologous to specific sites in the VACV genome.
Virus Rescue & Homologous Recombination: Transfer plasmids are transfected into VACV infected cells. Homologous recombination between the plasmids and viral genomes occurs in the cells, producing a recombinant virus carrying exogenous genes.
Purification and Screening: The crude virus lysate is harvested and goes through rigorous purification processes to isolate the recombinant viruses. We use multi wheel plaque detection and molecular screening (such as PCR, sequencing) to ensure the purity and genetic integrity of the final viral vector.
Viral Stock Production & Quality Control: Once pure recombinant virus is obtained, we will produce high titer virus stock solution. Our quality control (QC) program is extensive, including:
- Titer determination: Use plaque assay to quantify the number of infectious viral particles.
- Purity assessment: Verify the presence of contaminating viruses or mycoplasma.
- Genetic stability test: Confirm the sustained existence of exogenous genes through multiple passages.
- Expression validation: Detecting the expression of target proteins (such as Western blotting, ELISA).
What We Deal With: The Science of Vaccinia Viral Vector Engineering
Oncolytic Vaccine Virus for Cancer Treatment
Oncolytic vaccine virus for cancer treatment: Oncolytic virus is an engineered biological agent designed to selectively infect, replicate, and lyse cancer cells while largely protecting healthy tissues. VACV is naturally well suited for this treatment method due to its large physical size, natural orientation towards multiple cell types, and inherent oncolytic properties. Our complex engineering strategy focuses on improving tumor selectivity by deleting viral genes, which are crucial for replication in healthy, non-malignant cells but are unnecessary in many tumors cell metabolic and signaling environment changes (e.g. deleting thymidine kinase gene tk).
Recombinant Vaccine Vectors for Vaccine Development
Recombinant vaccine vectors for vaccine development: This application represents the cornerstone of our work. We carefully design VACVs to carry and express antigen encoding genes from infectious pathogens or specific cancer cells. After administration, the recombinant virus briefly replicates (or maintains replication defects, depending on the strain) within the host cell, leading to strong expression of these exogenous antigens. This expression effectively initiates and activates powerful cellular (such as cytotoxic T lymphocytes, CTLs) and humoral (antibody mediated) immune responses, which are crucial for protective immunity.
Frequently Asked Questions
Q: Why choose acne vector instead of other viral vectors such as adenovirus or lentivirus?
A: The smallpox vector has several key advantages: high cloning ability (up to 25kb), cytoplasmic replication (avoiding host genome integration), and strong safety due to its long history of human use.
Q: Is the smallpox virus safe for human use?
A: Yes, especially highly attenuated strains such as Modified Ankara Vaccinia (MVA), which have replication defects in human cells. MVA has been extensively studied and has a strong safety record, making it an ideal choice for vaccine applications.
Q: What is the turnaround time for custom vector projects?
A: The schedule varies depending on the complexity of the project, but standard vector construction and production services typically take 8-12 weeks from initial design to final delivery.
Customer Review
"We have collaborated with Creative Biolabs to develop a recombinant MVA vector expressing a novel tumor antigen for our preclinical cancer vaccine program. Their team was very knowledgeable and responsive throughout the entire process from the initial design phase to final quality control. The purity and titer of the obtained carrier are both high, and our antigen expression fully meets our expectations. Their meticulous methods and scientific rigor are evident at every step. We believe that this carrier will become a key component of our ongoing research, and we strongly recommend their services"
——Dr. Anya Sharma, Lead Scientist
Reach Out to Us Now!
The process of Creative Biolabs involves careful vector design, precise genetic engineering through homologous recombination, and meticulous purification and quality control. These carriers are designed as powerful tools for prevention and treatment applications. Due to their cytoplasmic replication and large cloning ability, they provide a safe alternative to other viral vectors. Our services range from customized vector design for antigen expression to the creation of potent oncolytic viruses; all aimed at advancing biomedical research and drug discovery. Please feel free to contact us for more details and our scientists will conduct further in-depth discussion on your project.
Reference
- Altenburg A F, Kreijtz J H C M, De Vries R D, et al. Modified vaccinia virus ankara (MVA) as production platform for vaccines against influenza and other viral respiratory diseases. Viruses, 2014, 6(7): 2735-2761. https://doi.org/10.3390/v6072735 (Distributed under Open Access license CC BY 4.0, without modification.)
