Photothermal Nanoparticles Immune Engineer Tumor-specific T cells for Adoptive Cell Therapy

PROJECT SUMMARY This goal of this proposal is to investigate a novel photothermal nanoparticle-based approach for generating tumor-specific T cells as an adoptive T cell therapy (ATCT) for glioblastoma (GBM). Despite being the most commonly diagnosed brain tumor, the prognosis for GBM patients is dismal, with a relative five-year survival rate of 7.5%. Hence, there is an urgent need for novel therapies for this patient population. In response, we are synthesizing novel Prussian blue nanoparticle-based formulations that will be used to administer photothermal therapy (PBNP-PTT) and generate a personalized ATCT for GBM. Our approach involves treating GBM tumor cells resected during surgery with PBNP-PTT ex vivo, and co-culturing them with dendritic cells (DCs) and T cells expanded from PBMCs sourced from the patient or a matched donor, to expand GBM-specific T cells for subsequent ATCT. We envision our therapy to be administered to patients after standard-of-care regimens of surgery, chemotherapy, and radiation therapy, when GBM patients are in a minimally residual disease state, with the goal of maximizing the impact of the T cell therapy thus improving survival outcomes. In a recently published study with GBM tumor cell lines, we demonstrated that PBNP-PTT generated more potent tumor-specific T cells in terms of specificity and cytolytic function, when compared to T cells generated by freeze-thaw lysis of the GBM tumor cells or by heating of the tumor cells on a heat block at equivalent thermal doses. In vivo, our immune engineered T cells eliminated orthotopically implanted U87 xenograft tumors and significantly improved survival compared to tumor-bearing animals treated with lysate-derived, antigen (PRAME)-specific, or PHA-expanded T cells, and control treatments. Operationally, our approach represents a more seamless workflow than other personalized approaches. It involves a straightforward, single administration of PBNP-PTT to the GBM cells isolated after surgery for 10 minutes using PBNPs pre-synthesized with GLP techniques and a portable laser, followed by well-established DC and T cell expansion protocols. Building on these promising findings, we now propose to synthesize multiple PBNP-PTT nanoformulations to generate and expand tumor-specific T cells and conduct studies testing their efficacy in vitro, in vivo, and ex vivo, as well as mechanistic studies. We hypothesize that PBNP-PTT of GBM tumor cells using our PBNP nanoformulations significantly enhances antigen release and capture by the PBNPs, their processing and presentation by DCs allowing more robust activation of a diverse T cell population, which subsequently differentiates into cytotoxic effector and long-lasting memory phenotypes, the ideal ATCT product for safe and effective treatment of GBM. Success in this project will demonstrate the use of PBNP-PTT nanoformulations to generate a transformative, new class of ATCT for GBM.