Abstract 5574: In vivo model development for immune cell-based therapeutics

Abstract

Abstract The implementation of various mouse models is critical to asses safety, efficacy, and short- and long-term persistence of therapeutic modalities, especially for cell-based therapies. To increase our repertoire of viable humanized murine models, we developed two in vivo models by taking advantage of Taconic's immunodeficient mice, one monitoring graft versus host disease (GvHD) and the other addressing human natural killer (NK) cell cytotoxicity. We utilized NOG mice to develop a model of GvHD, by transplanting human PBMCs at varying doses and monitoring mice for changes in body weight over time. We determined a dose of injected PBMCs that allowed for GvHD to occur yet provided a window of opportunity for potential therapies to slow progression. When human natural T regulatory cells (nTregs) were co-injected with PBMCs in NOG mice, there was prolonged survival and a less rapid loss of body weight as compared to PBMCs alone. To create an NK cytotoxicity model, we transplanted human primary NK cells into NOG-hIL15 mice, which are NOG mice that constitutively produce human IL-15. We showed successful engraftment and proliferation of NK cells, with peak engraftment occurring 4-5 weeks post injection, and that these human primary NK cells were able to persist without signs of xenogeneic GvHD. Utilizing K562 tumor cells that express luciferase, we found these engrafted NK cells have fast and potent cytotoxic activity using IVIS imaging, resulting in elimination of tumor cells as compared to non-engrafted mice. Our results collectively suggest that the two in vivo models developed here will be valuable tools for investigating the clinical benefit of immune cell-based therapeutics. Citation Format: Elizabeth McMichael, Utsav Jetley, Christopher Rudulier, Minasri Borah, Nicole Ganci, Vandhana Ragothaman, Ishina Balwani, Amanda Frain, Priya Pajanirassa, Yuko Miki, Jeffrey Jones, Troy Luster, Marie Keenan, Terina Martinez, Yong Zhang, Birgit Schultes. In vivo model development for immune cell-based therapeutics [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5574.