Clifford M. Csizmar
Entering Class: 2012
Boise State University
Chemistry and Pre-Medical majors
MSTP Student Governance:
- Student Admissions Committee, 2014-2016
- Student Advisory Committee, 2012-14
Honors and Awards:
- Ruth L. Kirschstein National Research Service Award for Predoctoral MD/PhD Fellows, National Cancer Institute, 2016-2020
- University of Minnesota Warren and Henrietta Warwick Fellowship, 2015-16
Thesis Advisor: Carston Wagner, Ph.D.
The ability to engineer and reprogram cell surfaces has the potential to enable and expand the use of cell-based therapies for cancer and tissue regeneration. Due to the numerous technical and clinical drawbacks of methods relying upon genetic engineering (e.g., chimeric antigen receptors [CARs]), our group has sought an alternative, non-genetic strategy to engineer cell surfaces and direct therapeutic cell-cell interactions. We have previously demonstrated that a fusion protein comprised of two units of E. coli dihydrofolate reductase (DHFR2) and an anti-EpCAM single-chain antibody (scFv) can be engineered to spontaneously form chemically self-assembled nanorings (CSANs) when combined with the chemical dimerizer bis-methotexate (bisMTX). When a phospholipid is conjugated to the bisMTX moiety, assembly of these species forms chemically self-assembled chimeric antigen receptors (CS-CARs) capable of targeting the carcinoma and cancer stem cell marker EpCAM. Furthermore, we demonstrated that the anti-EpCAM CS-CARs rapidly and stably insert into T cell membranes and drive the selective recognition and killing of EpCAM-positive breast cancer cells in vitro. A unique feature of our approach is the ability to deactivate the CS-CARs pharmacologically via incubation with the FDA-approved antibiotic trimethoprim. Despite these encouraging results, it is unclear whether the current CS-CAR constructs are optimal for the initiation and maintenance of therapeutic cell-cell interactions. Therefore, I am investigating the impact of the lipid-bisMTX conjugation chemistry, fatty acid composition, fusion protein linker lengths, and targeting scaffold identity (scFv vs Fn3) on the membrane insertion and target cell recognition capabilities of the CS-CARs. In collaboration with the laboratory of Dr. Ben Hackel, I am using yeast surface display and directed evolution to engineer a high-affinity anti-EpCAM fibronectin (Fn3) scaffold that can replace the scFv and enable soluble expression of our CS-CAR fusion proteins. Overall, our results are poised to enhance the field's understanding of engineering reversible cell-cell interactions and expand the use of clinical cell-based therapies.
For work prior to the UMN MSTP
Csizmar CM, Daniels JP, Davis LE, Hoovis TP, Hammond KA, McDougal OM, Warner DL. Modeling SN2 and E2 reaction pathways and other computational exercises in the undergraduate organic chemistry laboratory. J Chem Educ. 2013 Sept;90(9):1235-1238.
Csizmar CM, Force DA, Warner DL. Examination of bond properties through infrared spectroscopy and molecular modeling in the general chemistry laboratory. J Chem Educ. 2012 Feb;89(3):379-382.
Csizmar CM, Force DA, Warner DL. Implementation of gas chromatography and microscale distillation into the general chemistry laboratory curriculum as vehicles for examining intermolecular forces. J Chem Educ. 2011 July; 88 (7):966-969.