Part:BBa_K3346001

Usage and Biology

Antibodies have great potential for the design of diagnostics (immunoassays) and therapeutic applications (immunotherapy) [1]. With such high affinity to their target molecules, antibodies can effectively capture target analytes in in vitro samples or in in vivo systems. However, the use of immunoassays and immunotherapy is limited in part because of their high cost [2]. While mass production can help reduce the expenses associated with the use of antibodies in a project design, the cost burden can make it hard for teams with limited resources to design and implement synthetic biology projects that use these molecules. We decided to use synthetic biology to produce the antibodies for immunoassays and immunotherapies to lower the cost and make our diagnostic product more accessible to clinics and laboratories across the globe. This could additionally help other teams planning to use antibodies in diagnostic or therapeutic applications. This BioBrick was designed for efficient use in the modified E. coli strain SHuffle, which has an oxidative cytoplasm and additional chaperone proteins to ensure the proper formation of disulfide bonds [3].

The light chain portion of an antibody binds specifically to the target antigen, including both a variable portion and constant chain portion. Modified antibodies created for therapeutic purposes typically consist of the VH and VL regions along with the selected constant chains [4]. This indicates the importance of the light chain for proper antibody specificity and design. This variable chain sequence belongs to the therapeutic monoclonal antibody Siltuximab, which targets IL-6 in the treatment of Castleman’s Disease [5]. We selected this antibody for use in our diagnostic assay and production as a BioBrick as we believe it has potential as a therapeutic for endometriosis. Endometriosis patients exhibit elevated levels of IL-6, which can lead to pain, inflammation, and the progression of the disease [6]. As such, mass production of this antibody may lend itself to an affordable, personalized medicine approach for treatment of endometriosis symptoms.

This BioBrick can be used in combination with our other basic parts to create a functional, full-length IgG. Using standard assembly, this BioBrick can be combined with our constant region sequence to create the full-length Siltuximab fragment. Siltuximab includes the VH chain, a light chain, and three constant heavy chain regions (CH1, CH2, and CH3).

The sequence for the variable portion of the light chain was obtained from the IMGT Monoclonal Antibody Database. Since this sequence is owned by Janssen Biotech, we recommend that any individuals who build this BioBrick first reach out to Janssen Biotech for authorization. The murine constant light chain sequence was widely available as published on the UniProt database. These sequences were combined together in order to procure a chimeric monoclonal antibody using a murine constant chain. This allows for employment in our lateral flow assay, which uses an anti-mouse antibody at the control line.

[1] Khan, F. H. (2014). Chapter 25 - Antibodies and Their Applications (A. S. Verma & A. B. T.-A. B. Singh (eds.); pp. 473–490). Academic Press. https://doi.org/https://doi.org/10.1016/B978-0-12-416002-6.00025-0

[2] Hernandez, I., Bott, S. W., Patel, A. S., Wolf, C. G., Hospodar, A. R., Sampathkumar, S., & Shrank, W. H. (2018). Pricing of monoclonal antibody therapies: higher if used for cancer? The American Journal of Managed Care, 24(2), 109–112. http://www.ncbi.nlm.nih.gov/pubmed/29461857

[3] Robinson, M.-P., Ke, N., Lobstein, J., Peterson, C., Szkodny, A., Mansell, T. J., Tuckey, C., Riggs, P. D., Colussi, P. A., Noren, C. J., Taron, C. H., DeLisa, M. P., & Berkmen, M. (2015). Efficient expression of full-length antibodies in the cytoplasm of engineered bacteria. Nature Communications, 6(1), 8072. https://doi.org/10.1038/ncomms9072

[4] Juul, A., Scheike, T., Pedersen, A. T., Main, K. M., Andersson, A. M., Pedersen, L. M., & Skakkebaek, N. E. (1997). Changes in serum concentrations of growth hormone, insulin, insulin- like growth factor and insulin-like growth factor-binding proteins 1 and 3 and urinary growth hormone excretion during the menstrual cycle. Human Reproduction, 12(10), 2123–2128. https://doi.org/10.1093/humrep/12.10.2123

[5] Robinson, M.-P., Ke, N., Lobstein, J., Peterson, C., Szkodny, A., Mansell, T. J., Tuckey, C., Riggs, P. D., Colussi, P. A., Noren, C. J., Taron, C. H., DeLisa, M. P., & Berkmen, M. (2015). Efficient expression of full-length antibodies in the cytoplasm of engineered bacteria. Nature Communications, 6(1), 8072. https://doi.org/10.1038/ncomms9072

[6] Malvezzi, H., Hernandes, C., Piccinato, C. A., & Podgaec, S. (2019). Interleukin in endometriosis-associated infertility-pelvic pain: Systematic review and meta-analysis. Reproduction, 158(1), 1–12. https://doi.org/10.1530/REP-18-0618