Principal Investigator/Program Director (Last, First, Middle): Lee, Abraham, Phillip 7. Project Summary A major limitation of artificial antigen presenting cells (aAPCs) for adoptive T-cell therapy is the absence of a fluid membrane. This is a major concern since once a T-cell binds to an antigen-presenting cell (APC), the T- cell rearranges its membrane and cytoskeleton to form what is known as the ?immune synapse?. The synapse consists of a cluster of T-cell receptors surrounded by costimulatory and adhesion molecules. The formation of this synapse is essential to trigger a signaling cascade that activates the T-cell to divide and differentiate, and also causes it to produce cytokines. This project will focus on engineering cell-sized unilamellar vesicles (CUVs) as aAPCs to generate antigen-specific CD4+ T-cell responses. These aAPCs are converted from a storable (>8 months) double emulsion precursor generated by a novel microfluidic process.
Aim 1 will focus on optimizing the process to covert double emulsion droplets (DEDs) to cell-sized unilamellar vesicles (CUVs), both in size and membrane formation and stability. The microfluidic generated cell-sized unilamellar vesicles (CUVs) will be characterized for stability and membrane properties. The expected outcome would be a robust process to generate artificial cells for a wide range of cell-based therapies.
Aim 2 will focus on the functionalization of the lipid bilayer membranes of CUVs with MHC-II protein complexes to form immune synapses between the aAPCs and the T-cells. The formation of immune synapse synergizes enhancement of aAPC/T-cell binding through an increase in avidity. Membrane-bound adhesive proteins, such as the T-cell bound integrin LFA-1, surrounding these MHC-T clusters stabilize and prolong aAPC/T-cell interactions. The expected outcome is that a limited number of activating MHC?TCR complexes on the aAPCs will be sufficient to trigger T-cells.
Aim 3 will focus on investigating the conditions for optimal T-cell expansion and differentiation. By modifying the peptide sequences presented in the MHC-II complex of the aAPC it is possible to direct T-cells to attack different types of cancer cells in a specified manner. The expected outcome is significant increase in IFN-? production in CUVs coupled with NY-ESO as well as TT tetramer both by ELISA and flow cytometry. Enhanced T cell proliferation is also expected in this group.
Lee, Abraham, Phillip 8. Project Narrative Several recent studies have explored the potential of adoptive T-cell therapy and found success in inducing clinically relevant antitumor responses in patients suffering from advanced cancers. However, the lack of consistent clinical success in trials of adoptive immunotherapy with CD8+ T-cells has been partially attributed to a need for continuing CD4+ T-cell involvement to sustain a tumor-directed immune response in vivo. In this project, cell-sized unilamellar vesicles (CUVs) will be engineered as artificial antigen presenting cells (aAPCs) to generate antigen-specific CD4+ T-cell responses.
