Part:BBa_K3346005

Usage and Biology

Targeted drug delivery allows for the specific delivery of therapeutic hormones and antibodies to the most relevant physiological sites [1]. In endometriosis, targets for anti-estradiol therapeutic antibodies are the sites of estrogen biosynthesis, which includes ovarian, adipose, and skin fibroblast cells [2]. Since these processes occur intracellularly, cytosolic protein delivery allows therapeutic antibodies to target 17β-estradiol, which has been implicated in the progression of endometriosis and endometrial lesion growth [3]. Recent research has shown that the addition of an anionic peptide tag, a short amino acid sequence consisting of negatively charged residues, can bind to cationic delivery lipids in the bloodstream to allow for delivery of therapeutic antibodies into the cytosol [4]. This cytosolic delivery method has been reported at 90% efficiency at low concentrations (500 nM) of antibody, thus demonstrating its potential for use in immunotherapy [4]. The anionic peptide tag contains a linker region for attachment to therapeutic antibodies or Fab fragments followed by the 25 aspartate (D25) anionic region, optimized for delivery efficiency and low toxicity levels [4]. A GFP reporter gene is included for detection of cells with successfully delivered antibodies. This part allows for antibodies that would previously be unable to enter the cytosol, to target cytosolic molecules, such as 17β-estradiol.

This part can be used in conjunction with our anti-estradiol Fab fragment (BBa_K3346004) to create a potential therapeutic option for endometriosis.

1. Esteva FJ, Hubbard-Lucey VM, Tang J, Pusztai L. (2019). Immunotherapy and targeted therapy combinations in metastatic breast cancer. The Lancet Oncology, 20(3), 175-186.

2. Bulun SE, Zeitoun KM, Takayama K, Sasano H. (2000). Estrogen biosynthesis in endometriosis: molecular basis and clinical relevance. Journal of Molecular Endocrinology, 25(1), 35-42.

3. Kitawaki, J., Kado, N., Ishihara, H., Koshiba, H., Kitaoka, Y., & Honjo, H. (2002). Endometriosis: the pathophysiology as an estrogen-dependent disease. The Journal of Steroid Biochemistry and Molecular Biology, 83(1), 149–155.

4. Wang HH, Tsourkas A. (2019). Cytosolic delivery of inhibitory antibodies with cationic lipids. Proceedings of the National Academy of Sciences, 116(44), 22132-22139.