Abstract 13381: hiPSC of CIITA and B2M KO Derived Cardiac Cells Engineered 3D Spheroid Transplantation Induce Tachycardia in Myocardial Infarction in Swine

Abstract

Introduction: Human induced pluripotent stem cells (hiPSCs) are among one the most significant discoveries in life sciences. As a promising —biological drug for cell therapy, multiple lineages of iPSC-derived cardiac cells have been administered in human clinical trials in multiple important organ systems. The potential immunogenicity of hiPSC-derived cardiac cells continues to be one of the concerns in large animal models. Methods: In the present study, WT hiPSCs were generated by transfecting male human cardiac fibroblasts with Sendai viruses coding for OCT4, SOX2, KLF4, and C-MYC.Then hiPSCs carrying knockout mutations for both HLA Class I and Class II (HLAI/II-KOhiPSC) were generated via CRISPR/Cas9 gene-editing technology (Mattapally et al, 2018). hiPSCs were differentiated into cardiomyocytes (CM) endothelial cells (ECs) and spheroid cultured was performed as previously described (Mattapally et al, 2018). We evaluated spheroid transplantation and its potency for myocardial repair in the Swine. Programmed stimulation was used to determine the arrhythmogenic outcome. Results: To determine the engraftment efficacy of HLAI/II KO compared to WT Spheroid, a swine study was performed. After LAD ligation in swine, 800μm spheroid was injected into the border zone of the left ventricle. After transplantation, cell engraftment was monitored by Q-PCR. At week 4, there was a significant difference between the 2 groups. Animal groups included: MI hearts treated with 500 WT Spheroid injection (MI+WT Spheroid, n=5), MI hearts treated with 500 KO Spheroid injection (n=6), MI only hearts (n=6); the fourth group of animals underwent sham surgery (Sham, n=6). Arrhythmia was studied by programmed electrical stimulations (PES) and conduction velocities measured with electrode mapping, and the engraftment rate by calculation of quantitative polymerase chain reaction measurements of expression of the human Y chromosome. Engraftment of iPSC-CMs was found in both treatment groups; however, a significantly higher engraftment rate was found in KO Spheroid. The spheroid treatment is associated with significant changes in arrhythmogenicity. Conclusion: Our study established the improved graft but associated with arrhythmogenicity.