T cells are being infused into patients and the anti-tumor response is due, in part, to the ability of these immune cells to migrate to sites of disease and traffick within areas of high interstitial pressure to specifically deliver their payload of lytic granzymes and perforin. Despite this premise, the promise of T-cell therapy has been limited by (i) immunologic tolerance against tumor antigens preventing T cells being generated with desired specificity, and (ii) emergence of escape variants that are resistant to the endogenous lytic effector function of T cells. To overcome these limitations, we will evaluate the use nanotechnologies to introduce a novel chimeric antigen receptor (CAR) to redirect T-cell specificity to a tumor for cell-based delivery of silica nanobeads pre-loaded with the cytotoxic drug doxorubicin. This will be achieved by the development and application of proprietary high-throughput devices that use nanosecond electroporation (nano-EP) to efficiently introduce CAR and silica nanobeads. This combination of nano-engineering and gene therapy is strengthened by our existing clinical platforms to propagate and genetically modify T cells for human gene therapy trials of cancer and by the collaborations with two institutions within the Texas Medical Center.

In collaboration with Rice University, we are developing a series of devices for the electro-transfer of mRNA to express a CAR specific for CD20, expressed on the surface of B-cell malignancies. In collaboration with The University of Texas Health Science Center at Houston (UTHSC-H), we are developing novel nanoparticles for the delivery of chemotherapy drugs by T cells. Using the pre-center award we will continue to combine these three institution’s efforts to develop a new platform for targeted nano-therapy in which cells can be infused with hours of electro-transfer to deliver a targeted cytotoxic payload to tumor cells. This will be achieved in four aims. Specific Aim #1 will be to generate a device to synchronously electroporate T cells to introduce desired mRNA and silica nanobeads. Specific Aim #2 will use the device from aim #1 to introduce mRNA coding for a CD20-specific CAR to redirect T-cell specificity for CD20+ lymphomas. In Specific Aim #3, we will use nano-EP to introduce silica nanobeads loaded with doxorubicin into CAR+ T cells. The nanobeads prevent T cells from undergoing damage while carrying the nanoparticles. After binding CD20, the CAR will deliver an apoptotic signal to destroy the T cells thereby releasing doxorubicin packaged within the nanoshells. In Specific Aim #4, we will extend membership of our pre-center grant team to include Texas A & M to evaluate the anti-tumor activity of CAR+ drug-loaded canine T cells in dogs with spontaneously occurring CD20+ lymphoma. After two years of funding it is expected that the team will have developed and tested a new approach using T-cell immunobiology to target the tumor and to deliver the silica nanobead cytotoxic payload in order to bypass the resistance of tumors to lysis by endogenous T cells.