The incidence of melanoma is increasing worldwide, and the prognosis for patients with advanced or metastatic melanoma remains poor due to limited treatment options. Adoptive cell therapy (ACT) with antigen- specific CD8+ T cells is a promising approach for treating patients with chronic viral infections and a variety of malignancies including melanoma. A major limitation of ACT is poor survival of T cells in vivo following infusion. Less-differentiated T cells with long telomeres are the ideal T-cell subset (termed highly avid T cells) for ACT- based immunotherapy; however, generating large numbers of these young T cells is problematic. This limitation can be overcome by using induced pluripotent stem cells (iPSCs) as an unlimited source of T cells against targeted antigens. T cells differentiated from human T cell-derived iPSCs harbor long telomeres and exhibit antigen-specific killing effector functions in vitro. Despite these findings, there is a gap in our knowlede regarding the in vivo safety and therapeutic efficacy of ACT using iPSC-derived T cells. The objective of this proposal is to determine safety and therapeutic efficacy of iPSC-derived T cells in a novel preclinical model. The overarching hypothesis is that T cell-derived iPSCs differentiate into highly avid, long lived antigen- specific T cells that will mediate anti-tumor immunity in the absence of tumor formation and immune rejection. We will test this hypothesis using three specific aims to ensure that: 1) T cell-derived iPSCs display no immunoreactivity and tumorigenicity in vivo; 2) iPSCs differentiate into highly avid antigen-specific T cells that elicit anti-tumor immune response against murine tumors; and 3) targeting T-cell inhibitory pathways by genome editing in iPSCs will allow generation of T cells with enhanced anti-tumor immunity. Given that ACT is safe and effective in patients with cancer and chronic viral infection, successful completion of this proposed study will provide a solid foundation for the future development of ACT using immune cells derived from patient-specific iPSCs and, ultimately, for eradication of disease. As an academic surgical oncologist, I have clinical and research interests in melanoma. As a faculty member at the University of Michigan, my clinical specialty will be treating patients with advanced melanoma and my research program will facilitate the development and application of more effective cancer immunotherapy. The Department of Cell and Developmental Biology and UM Comprehensive Cancer Center have a world-class faculty and facilities. In particular, I will benefit from thoughtful, hands-on mentoring by experienced scientists and clinicians who are deeply committed to my success.
The incidence of melanoma is increasing worldwide, and the prognosis for patients with advanced or metastatic melanoma remains poor due to limited treatment options. Despite encouraging results in preclinical models and in patients current protocol of adoptive cell therapy (ACT) with antigen-specific CD8+ T cells has major limitations, poor survival of infused T cells and the existence of immune suppressive pathways. This project utilizes a novel preclinical model for determining in vivo safety and therapeutic potential of induced pluripotent stem cell-derived T cells for ACT to overcome these limitations.
