Carston Wagner, PhD
University of Minnesota, Twin Cities

Hosted  by Jennifer Golden

Non-Genetic Engineering of Cell-Cell Interactions for Cancer Immunotherapy and Beyonds

The ability to direct targeted intercellular interactions has the potential to enable and expand the use of cell-based therapies for regenerative medicine, tissue engineering, and immunotherapy.¹ While genetic engineering approaches have proven effective, these techniques are not amenable to all cell types and often yield permanent modifications with potentially long-lasting adverse effects, restricting their application. To circumvent these limitations, our laboratory has designed chemically self-assembled nanorings (CSANs) that can be used as prosthetic antigen receptors (PARs) for the non-genetic modification of cell surfaces. PARs are formed by fusing a peptide or protein ligand to two linked dihydrofolate reductase (DHFR²) molecules that spontaneously assemble into octomeric CSANs upon the addition of a chemical dimerizer, bis-methotrexate (bisMTX). This unique platform allows for the incorporation of highly stable multivalent binders to a cell surface. We have applied this approach for the modification of T-cell surfaces by incorporating an anti-CD3 fusion protein with a tumor targeting fusion protein resulting in the formation of bispecific PARs that selectively target T-cells to tumor cells. A unique feature of PARs, is the ability to pharmacologically remove them from the T-cell surface with and FDA approved drug. Using a mouse orthotopic breast cancer xenograft model, we have demonstrated that PAR T-cells can eradicate tumors from the animals. ² Recently, we have also demonstrated that PARs can be designed that result in T-cell eradication of triple negative breast cancer tumors by targeting both the primary tumor cells and tumor initiating cancer stem cells. Ongoing efforts by our laboratory to expand PAR based approaches for cell-cell interaction engineering³, as well as to quantitatively assess the interplay between ligand binding, multivalency and antigen surface expression will be discussed.

1. Csizmar, Clifford, M., Petersburg, Jacob R., and Wagner, Carston R., “Programming Cell-Cell Interactions Through Non-Genetic Membrane Engineering”, Cell Chemical Biology, 25, 931-940 (2018)
2. Petersburg, Jacob R., Jingjing Shen, Jingjing, Csizmar, Clifford M., Murphy, Katherine A Spanier, Justin, Gabrielse, Kari, Griffith, Thomas S., Fife, Brian and Wagner, Carston R., “Eradication of Established Tumors by Chemically Self-Assembled Nanoring (CSAN) Labelled T-Cells”, ACS Nano, 12, 6563–6576 (2018)
3. Csizmar, Cliff M., Petersburg, Jacob R., Hendricks, A., Stern, Lawrence A., Hackel, Benjamin J., and Wagner, Carston R.. “Engineering reversible cell-cell interactions with lipid anchored prosthetic receptors”, Bioconjugate Chemistry, 18, 1291-1301 (2018)