3026-LB: Development of Engineered iPSC-derived Clinical Islets and Noninvasive Monitoring of Immune Attack in Mice

Introduction and Objective: We are developing engineered iPSC-derived islets for the clinic that can report graft status non-invasively after transplantation. Here, we present in vitro and in vivo performance data for engineered human iPSC-derived clinical line islets. Additionally, we show islets monitored non-invasively post-transplantation in both immunocompromised and immune-competent mice as a demonstration of monitoring immune attack in vivo. Methods: All in vivo data presented are from mice that have been transplanted with iPSC islets that are loaded with NanoTrackers. Non-invasive imaging is accomplished by Surface-Enhanced Raman Spectroscopic (SERS) imaging of the NanoTrackers that are Raman reporter-labeled gold nanostars. Immune attack is imaged in C57 Black 6 mice with intact immune systems and cell grafts transplanted in the intramuscular (IM) space of the hind leg. In vitro performance testing of engineered clinical iPSC islets include gene expression, protein abundance, and insulin secretion. In vivo demonstration of function of engineered clinical iPSC islets is shown by glycemic control in diabetic NSG mice. Results: All mice transplanted with engineered clinical iPSC islets retain normal fed blood glucose levels (155 +/- 43 mg/dL) while control animals without iPSC islets become hyperglycemic (564 +/- 36 mg/dL) at two weeks post diabetes induction. NanoTrackers show images of graft rejection in immunocompetent mice within two weeks of transplantation of engineered islets in the IM space, whereas NanoTrackers show no evidence of graft rejection in the immunocompromised mice. In immunocompromised mice, imaging of NanoTrackers in transplanted iPSC islets have been monitored out to 6 months, showing the stability of the NanoTracker platform. Conclusion: We are developing a clinically relevant iPSC islet source that is proven to control diabetes and is engineered to be able to monitor cell grafts in the event of an immune rejection or other engraftment challenges after transplantation. Disclosure S. Puri: Employee; Current; Minutia. J. Register: Employee; Current; Minutia. K. Digovich: Employee; Current; Minutia, Inc. Funding Breakthrough T1D (#2-IND-2023-1294-I-X)