Gene-deleted attenuated veterinary vaccines are vaccines in which the genes associated with virulence in the pathogen are deleted through modern genetic engineering techniques, resulting in a weakening or disappearance of its virulence, while retaining the immunogenicity and replication ability. BioVenic provides a full range of gene-deleted attenuated veterinary vaccine development services, from the search for virulence gene targets to assessments of all aspects of the developed vaccine, we take you into consideration and help you turn your thinking into reality.
Our Services
Genome Sequencing and Analysis
Searching for virulence genes is the first step in the development of gene-deleted attenuated veterinary vaccines. Where pathogen virulence target genes have not yet been identified, after sequencing the genome of the pathogen, sequence analysis can be used to obtain information about genes and their functions by deciphering gene sequence. BioVenic provides the service by analyzing pathogen genomic data to identify potential immunogenic genes and develop gene deletion strategies to select appropriate genes for deletion to obtain the ideal vaccine candidate.
Construction of Gene-Deleted Strains
The construction of gene-deleted strains is a very important part of live veterinary gene deletion vaccines. As the key to successful vaccine development, BioVenic offers a variety of recombination technology platforms.
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Gene Homologous Recombination
Homologous recombination is a type of genetic recombination in which nucleotide sequences are exchanged between two similar or identical molecules of DNA. BioVenic utilizes this principle to perform seamless cloning to achieve the deletion of the target gene. We provide the service of vector plasmid preparation and linearization. Using the specific fragments at both ends of the genes to be deleted. Company designs recombinant vectors with the same fragments and recombines the fragments that need to be introduced into the target genome into the vectors with tagged genes (e.g., neo genes, TK genes, etc.) to become the recombinant vectors. The exogenous sequence is then homologously recombined with the pathogen DNA to achieve allelic replacement of the target gene. This technique is simple to operate and is not limited by the enzyme cutting site, which makes the efficiency increase.
Fig. 1 How does homologous recombination work? (BioVenic Original)
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CRISPR-Cas9 Genome Editing
The full name of CRISPR is Clustered Regularly Interspaced Short Palindromic Repeats and Cas means CRISPR-associated (Cas) endonuclease, or enzyme, which is a highly efficient gene editing technology. Company uses it to remove the target gene fragments from pathogens. The system consists of two main components: the Cas9 nuclease and a guide RNA (gRNA) that characteristically binds to the target gene. BioVenic provides sgRNA design and synthesis services, enabling the sgRNA to form a complex with the Cas9 enzyme, known as an RNA-protein complex (RNP), which directs the cas9 enzyme to target the genome-specific site for shearing, creating a double-strand break. The cell then repairs using homologous recombination, allowing specific DNA fragments to be inserted or replaced during the repair process, enabling gene deletion.
The Cre-LoxP system from P1 phage is an effective and specific system to control gene expression. The system consists of two parts: specific Cre recombinase and specific loxP site. Protein Cre recombinase can recognize 34 bp loxP sites and perform specific cutting and splicing. The orientation and location of loxP sites determine how the genetic material will be rearranged, and if two sites are oriented in the same direction, the sequence between loxP sites is excised (and not retained) as a circular DNA fragment. By expressing Cre at a specific time or location you can precisely control the expression of target genes, and BioVenic offers you plenty of Cre recombinase plasmids. After deletion, we also apply services such as viral plaque assay for screening and purification of pathogens.
Stability Assessment
Deletion of specific genes may have an impact on the growth and replication of the pathogen, and there is also a risk of potential genetic mutation. BioVenic evaluates the genetic stability of gene-deleted attenuated veterinary vaccines by performing pathogen gene sequence analysis after successive passages to check for the presence of base mutations at the gene deletion. Also of concern is the possibility that the vaccine seed may reacquire the gene through recombination between vaccine strain and wild strain. BioVenic provides in vivo and in vitro platforms to test for the loss of fluorescent reporter genes by stimulating the vaccine strain in the presence of the wild strain and after multiple passages of growth.
Gene-Deleted Attenuated Veterinary Vaccine Development Services
We also offer the following basic vaccine development services, covering all aspects to ensure the overall success of your veterinary gene-deleted attenuated vaccine R&D program.
Formulation Development
BioVenic adds the appropriate adjuvants to enhance immunogenicity according to your vaccine requirements. We also take into account the fact that gene-deleted attenuated veterinary vaccines often require cold chain storage and transportation, and provide excipients to increase the stability of the vaccine.
In Vitro Assays
BioVenic offers advanced in vitro assays to evaluate the properties of vaccine candidates, which help predict vaccine safety and potency.
In Vivo Assays
BioVenic provides in vivo assays with comprehensive animal models, evaluating the safety, potency and efficacy of vaccines.
Contract Manufacturing
Our modern manufacturing facilities and technologies support the production of vaccines from small to large scale, while providing stringent quality control to ensure the high level of vaccines.
Applications of Gene-Deleted Attenuated Veterinary Vaccines
Both natural infection and vaccination induce a protective immune response, and detecting antibodies in an animal's serum may not distinguish between infected and vaccinated. Gene-deleted attenuated veterinary vaccines remove virulence-related genes and test the animal for antibodies against that particular antigen, allowing DIVA (differentiating infected from vaccinated animals) to occur. Only naturally infected animals produce antibodies against the antigen. Serological tests, such as ELISA, will provide this distinction and enable eradication in the case of vaccination. Compared with traditional vaccines, gene-deleted attenuated veterinary vaccines can differentiate between immunized animals and naturally infected animals, which is conducive to the development of animal disease purification program, to eradicate the disease.
Why Choose Us?
Choose BioVenic as your primary partner in the development of gene-deleted attenuated veterinary vaccine. With our deep expertise, BioVenic uses a collaborative approach to provide you with multiple technology platforms to ensure the construction of gene-deleted strains, ensuring that veterinary vaccine candidate meets high standards of safety, stability and efficacy. Contact us now and embark on a journey of cutting-edge solutions to enhance health of livestock, poultry, companion animals, aquaculture species and more.
