OR19

Universal allogeneic regulatory T cell therapy from genetically engineered iPSCs

C Plaisse(1) A Le Bozec(1) M d'Arco(1) L Tesson(1) L David(1,2) M Giraud(1) C Guillonneau(1) S Bézie(1)

1:Nantes Université, CHU Nantes, INSERM, Center for Research in Transplantation and Translational Immunology, UMR 1064, 44000 Nantes, France; 2:Nantes Université, CHU Nantes, INSERM, CNRS, BioCore, SFR Bonamy, 44000 Nantes, France

Organ transplantation and autoimmune disease treatments require innovative immunotherapies to replace non-specific immunosuppressants, which often compromise patients’ health. Cell therapy using autologous regulatory T cells (Tregs) has emerged a promising alternative. However, this approach is hindered by limited cell availability, extensive and costly procedures. To address these limitations, we aim to develop a universal allogeneic Treg therapy derived from induced pluripotent stem cells (iPSCs). Using CRISPR/Cas9, we generated non-immunogenic iPSCs by targeting B2M and CIITA to silence MHC-I and MHC-II expression. To protect these cells from Natural Killer (NK) cell-mediated lysis and promote differentiation toward Tregs, we transduced them with HLA-E and FOXP3, respectively. These engineered iPSCs retained the ability to differentiate into CD34+ hematopoietic progenitors, we established several iPSC master cell banks to evaluate the benefits of each modification. Subsequently, we optimized T cell maturation from CD34+ cells from cord blood by comparing two methodologies: the Artificial Thymic Organoid (ATO) model and a Notch-dependent feeder-free system. Interestingly, the ATO model yielded robust numbers of mature CD8+ T cells. In contrast, the feeder-free culture produced lower yields, but demonstrated greater potential for clinical applications. Our results demonstrate the feasibility of generating universal allogeneic Tregs from iPSCs, offering a scalable and clinically relevant approach for transplantation and autoimmune diseases applications.