Engineering human stellate cells for beta cell replacement therapy promotes in vivo recruitment of regulatory T cells

• Published in: Materials today bio 2019-03, Vol.2, p.100006-100006, Article 100006
• Main Authors: Oran, D C, Lokumcu, T, Inceoglu, Y, Akolpoglu, M B, Albayrak, O, Bal, T, Kurtoglu, M, Erkan, M, Can, F, Bagci-Onder, T, Kizilel, S
• Format: Article
• Language: English
• Subjects: Full-Length
• ISSN: 2590-0064; 2590-0064
• DOI: 10.1016/j.mtbio.2019.100006

Type 1 diabetes (T1D) is an autoimmune disease characterized by destruction of pancreatic β cells. One of the promising therapeutic approaches in T1D is the transplantation of islets; however, it has serious limitations. To address these limitations, immunotherapeutic strategies have focused on restoring immunologic tolerance, preventing transplanted cell destruction by patients' own immune system. Macrophage-derived chemokines such as chemokine-ligand-22 (CCL22) can be utilized for regulatory T cell (Treg) recruitment and graft tolerance. Stellate cells (SCs) have various immunomodulatory functions: recruitment of Tregs and induction of T-cell apoptosis. Here, we designed a unique immune-privileged microenvironment around implantable islets through overexpression of CCL22 proteins by SCs. We prepared pseudoislets with insulin-secreting mouse insulinoma-6 (MIN6) cells and human SCs as a model to mimic naive islet morphology. Our results demonstrated that transduced SCs can secrete CCL22 and recruit Tregs toward ​the implantation site . This study is promising to provide a fundamental understanding of SC-islet interaction and ligand synthesis and transport from SCs at the graft site for ensuring local immune tolerance. Our results also establish a new paradigm for creating tolerable grafts for other chronic diseases such as diabetes, anemia, and central nervous system (CNS) diseases, and advance the science of graft tolerance.