Triple Body is a unique multi-specific fragments antibody which possesses proven effect in cancer therapy. With our multiple elaborately integrated platforms, Creative Biolabs can provide customer with an expected triplebody with high affinity and low immunogenicity.
Triple bodies are the combination of Fab with additional entities. As we know, the correct pairing of different chains is a great challenge in BsAb development. For conventional IgG, the heavy (Fd) and light chain of a Fab fragment can heterodimerize naturally in vivo. Based on which, the combination of Fd and LC can be worked as a scaffold and additional functionalities, such as peptide, scFv, cytokines, etc., can be incorporated, which could form triple bodies.
As mentioned above, based on the Fab scaffold, both Fd and LC can be extended with additional scFv bindiers or other functional entities at both the N- and C-terminal side theoretically. Considering that N-terminal extension may affect the antigen binding of Fab, the preferred model is to extend at the C-terminal side. The fused parts are various type of molecules, same or different, which lead to bispecific (1+1, 2+1), trispecific (1+1+1) molecules as well as immunocytokines, immunotoxins, enzyme fusions, etc. Different constructs of triple bodies are produced in a variety of host cells, prokaryotic or eukaryotic expression systems. During the expression of triple bodies, the nonnatural sequences of linkers connecting the scaffold and binders and in the scFv moiety may be the main drawback. The difficulties are usually overcome by choosing those sequences resembling natural human linker sequences or widely used flexible sequences or optimizing expression system at the early stage.
Figure 1. The constructs of triple body
A significant objective for the development of anti-cancer antibody agents is to additionally improve the specificity of cancer cell targeting over that of normal cells. One strategy is the production of dual-targeting agents, which are recombinant proteins with two antigen binding domains bind to two different antigens on a tumor cell. In some situations, it is probable to find a pair of target antigens that is widely present on cancer cells, while normal cells carry only one of these markers. In other situations, double-positive cancer cells take the pair in greater combined density than double-positive normal cells. Therefore, the expectation is that in both situations a dual-targeting agent can bind with greater probability to the cancer cell and over time enable to achieve a preferential elimination of cancer cells in vivo. The goal can be achieved by utilizing triple bodies which are engineered be bispecific for the target cells and monospecific for the effector cells. Clearly, triple bodies have the potential to work as multi-binding agents. We have generated some triple body successfully and provide custom generation services.
With the well-established triplebody generation platform, the experienced scientists here at Creative Biolabs are dedicated to help you develop unique triplebody. We also provide other various services regarding BsAbs development. Please feel free to contact us for more information and a detailed quote.
1. Braciak, T. A.; et al. NK cells from an AML patient have recovered in remission and reached comparable cytolytic activity to that of a healthy monozygotic twin mediated by the single-chain triplebody SPM-2. Journal of translational medicine. 2013, 11(1): 289.
2. Kim, J. H.; et al. Crystal structures of mono-and bi-specific diabodies and reduction of their structural flexibility by introduction of disulfide bridges at the Fv interface. Scientific Reports. 2016, 6: 34515.