Design of Yeast Based Vaccines for Cancer
The broad applicability of the yeast-based immunotherapy to elicit protective T cell immune responses has been demonstrated in preclinical studies with numerous foreign, mutated, and overexpressed antigens. Creative Biolabs is a world leader in the field of cancer vaccine development. With our extensive experience and advanced platform, we are therefore confident in offering the best development services for yeast-based vaccines. We guarantee the finest results for our customers all over the world.
Yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. They are estimated to constitute 1% of all described fungal species. Yeasts are unicellular organisms which evolved from multicellular ancestors, with some species having the ability to develop multicellular characteristics by forming strings of connected budding cells known as pseudo hyphae or false hyphae. Most yeasts reproduce asexually by mitosis, and many do so by the asymmetric division process known as budding.
Yeast Based Vaccines for Cancer
The yeast-based immunotherapy platform has been used for immune responses against a variety of foreign, mutated, or self-antigens. The number of yeast administered and the amount of antigen per yeast are two critical elements of yeast-mediated immune responses.
- Controlling Plasmid Copy Number.
The advantage of integrating the heterologous expression cassette into the yeast genome is the inherent stability of replicating chromosomes with each cell division. This means that yeast can be cultured in rich, nonselective media that allow for shorter generation times and the density of yeast number per liter of culture is typically an order of magnitude higher than that of yeast grown in minimal selective media. However, the number of copies of the desired gene product is then limited to the number of copies integrated into the yeast genome. Episomal plasmids may be engineered to encode replication regulatory sequences that dictate how many plasmid copies will be maintained in yeast cells with each cell division.
- Promoter Choice: Inducible, Constitutive, or Repressible.
The second key element for engineering high-level heterologous protein expression is the choice of promoter for regulating transcription of the heterologous gene. The type of promoter employed will be influenced by several interrelated factors, such as the need to control the timing of antigen expression, the impact of foreign protein expression on yeast cell health, and whether multiple antigens are produced from one or multiple plasmids within the yeast. The ability to control the rate of mRNA (and protein) accumulation is useful in cases where the antigen is toxic to the yeast cell and/or prone to aggregation. For such proteins, the investigator may need to have control over the rate and timing of mRNA synthesis. This may be achieved through the use of so-called rheostatic promoters—those that can be regulated by the addition of chemical compounds to the cell growth medium. By lowering the transcription rate (e.g., by adding a repressor compound) or initiating transcription late in the yeast culturing process, a heterologous protein that interferes with normal yeast growth may be better produced to higher levels, in addition to yielding higher-density cell harvest. For aggregation-prone proteins, slow or delayed synthesis is sometimes the key to avoiding these unproductive complexes because the protein molecules of interest are allowed to completely fold before encountering other partially folded proteins.
Creative Biolabs is a leader in the field of vaccine development and has focused on the cancer vaccines for years. We have experienced experts and advanced platforms that are able to provide excellent services. If you are interested in our services, please contact us for more details.
All of our products can only be used for research purposes. These vaccine ingredients CANNOT be used directly on humans or animals.
