Exploring DNA nanotechnology: Enhancing the NK cell immune response against tumors.

Cell immunotherapies have revolutionized clinical oncology. While CAR T cell therapy has been very effective in clinical studies, off-target immune toxicity limits eligible patients. Thus, NK cells have been approached with the same therapy design since NK cells have a more favorable safety profile. Therefore, the purpose of this research project is to explore DNA nanotech-based NK cell engagers (NKCEs) that force an immunological synapse between the NK cell and the cancer cell, leading to cancer death. DNA tetrabody (TB) and DNA tetrahedron (TDN) are fabricated and armed with HER2 affibody for tight adhesion to HER2+ cancer cell lines like SKBR3. Overall, relationship between TB-NK treatment and cancer cell apoptosis is still unclear. TB-NK treatment induces an apoptotic profile similar to PMA/IO stimulation. Pilot cell assay needs to be replicated with additional controls and a shortened treatment window. For DNA TDN fabrication, HER2 affibody polishing with Ni-NTA affinity chromatography achieves high purity with 20% to 100% high-imidazole elution gradient. ssDNA-HER2 affibody conjugation is optimal when ssDNA is treated with 40-fold excess sulfo-SMCC for 4 hours. In conclusion, the manufacturing of DNA-based NKCEs is rapid and streamlined, which gives these NKCEs the potential to become a ready to use immunotherapy.