Cancer Vaccines Based on Optimized Cryptic Peptides from TAA

Cancer has always been the number one killer of human health. Traditional cancer therapies have certain limitations. Vaccines are increasingly showing their important role in disease prevention and control. Creative Biolabs is a company focused on vaccine research with a top R&D team and more than a decade of R&D experience. In the development of cancer vaccines, we are at the international advanced level.

Optimized Cryptic Peptides

Neo-antigen is not recognized by the immune system as self-component and is immunogenic, which is its two main characteristics and the reason why it is being developed as a promising cancer vaccine. Despite these advantages, since the use of neo-antigen is limited by the genetic heterogeneity of the tumor as well as the high time and economic cost of identifying neo-antigen, the need to develop neo-antigen like vaccines that avoid self-tolerance and are immunogenic has emerged. Antigen-presenting cells are not uniform for the presentation of various peptides produced during TAAs processing. These peptides can be classified into dominant peptides that have high affinity for HLA-I and are highly expressed on the surface of tumor cells, and cryptic peptides that have low affinity on the surface of tumor cells with low expression level. Immunodominant peptides are more immunogenic, but the clinical effects of tumor vaccines targeting such antigens are poor. The important reason is that the immune system is self-tolerant to these antigens. In contrast, the immune system has little or no tolerance to cryptic peptides. One study showed that HLA-A*0201 transgenic mice are not tolerant to HLA-A*0201 restricted cryptic peptides from TERT, as confirmed by other models. All of these indicate that the immune system recognizes cryptic peptides from self-antigens as alien components, and because of their low immunogenicity, they do not have the risk of causing an autoimmune response. Therefore, once the disadvantage of low immunogenicity is overcome, TAA-derived cryptic peptides will be promising targets for cancer vaccines.

Table 1. Characteristics of neo-antigens and TAA-derived optimized cryptic peptides.

Considerations for Improving the Immunogenicity of TAA-derived Cryptic Peptides

The recognition of cryptic peptides from TAA by the immune system as non-self is an advantage for its being used as tumor vaccine, but to be an ideal cancer vaccine target, the antigen needs to have good immunogenicity. The reason for the poor immunogenicity of cryptic peptides is their low affinity with HLA-I molecules, so the strategy to increase their immunogenicity is to increase their HLA-I affinity. HLA-I has a preference for amino acid residues at the position of the epitope to which it interacts, so the introduction of amino acids that facilitates HLA-I binding at the primary or secondary anchor position of the cryptic peptide epitope is the main method to enhance its HLA-I affinity.

Cancer vaccines with TAA targets are generally not clinically effective, while vaccines targeting neo-antigen have higher time and economic costs. The optimized cryptic peptides from TAA, which combines immunogenicity and low self-tolerance, has become a promising broad-spectrum cancer vaccine candidate. Creative Biolabs has conducted extensive research and experimentation in this area, has mastered advanced technology and accumulated a wealth of experience, as well as helped tumor vaccine researchers around the world to complete the development of cancer vaccines perfectly.

All of our products can only be used for research purposes. These vaccine ingredients CANNOT be used directly on humans or animals.