CellRaft Array for Screening and Isolation of Highly Effective Cytotoxic T Cells

PROJECT SUMMARY: Cell Microsystems, Inc. is an early-stage biotechnology company whose mission is the commercialization of a novel, cost-effective platform enabling the identification and efficient isolation of viable cells based on morphologic and fluorescence signatures as well as characteristics that change over time. The CellRaft? technology is based on a unique cell array recently developed by the Allbritton Lab at the University of North Carolina at Chapel Hill. The commercially available CellRaft platform for cell identification and isolation consists of a sterile, disposable microarray (the CellRaft Array) for culturing cells and a motorized release device fitting on a standard inverted laboratory microscope for cell isolation. In the current grant application, we propose to expand our market applications by developing the technology for identifying and isolating non-adherent immunologic cells based on a unique time-resolved selection criterion, a feat not possible with other cell isolation procedures. The approach will combine the CellRaft Array with a cell-based cytotoxicity assay to identify and collect antigen-specific cytotoxic CD8+ T lymphocytes (CTLs). The eventual goal for this project will be to use the platform to isolate highly efficient killer cells for adoptive cell therapy (ACT). ACT is an emerging immunotherapy which shows significant promise in the treatment of both leukemia and solid tumors. ACT consists of the isolation and ex vivo expansion of CTLs recognizing epitopes of a mutated or aberrantly expressed protein present almost exclusively on the surface of a patient?s tumor cells. We envision the CellRaft system will serve both as a research tool enabling correlation of killing efficiency with the molecular characteristics of the T cell receptor (TCR) and eventually as a clinical tool for producing and identifying efficacious CTLs for cell-based therapies. In this regard, we envision the ideal approach to individualize ACT would be to identify, enrich and expand a population of highly efficient CTLs against a patient?s tumor without a priori defining a tumor-specific antigen, but this feat is not currently possible, primarily due to technical limitations. To overcome this and other obstacles, we seek to develop a high-throughput technology to efficiently generate highly-active, tumor- directed CTLs. In this initial Phase I STTR proposal, we will optimize the array for the cell-based cytotoxicity assay, improve the protocol for isolating the non-adherent lymphocytes and perform feasibility testing by using the CellRaft technology to identify and isolate effective CTLs. These efforts will lay the groundwork for a follow-on Phase II proposal to scale-up the array size, and integrate automated high-throughput image cytometry and cell isolation procedures to enable the molecular characterization of efficient killer T cells.