Abstract
Stem cell–derived β cells offer a promising approach for type 1 diabetes (T1D) treatment. However, the processes of graft infiltration and rejection by immune cells remain poorly understood in humans. In this study, autologous or allogeneic stem cell–derived islets (SC-islets) were transplanted in human immune system mice and analyzed 14 to 18 weeks later. Imaging mass cytometry revealed unique characteristics of SC-islet grafts, including a high percentage of glucagon+ cells and the presence of cysts and CD57+ enterochromaffin cells, features not typically observed in endogenous or transplanted allogeneic primary pancreatic islets. Allogeneic SC-islet grafts exhibited heavy immune infiltration, cell proliferation, and pro-fibrotic processes, whereas autologous grafts showed minimal infiltration and little fibrosis. In some mice, autologous T cells expressing islet antigen-reactive (IAR) T cell receptors (TCRs) were adoptively transferred. Three weeks after transfer, autologous grafts injected with IAR-TCR+ T cells showed negligible immune infiltration, even though IAR-TCR+ T cells were detected in the spleen. Under the conditions tested, human SC-islet grafts were not rejected by an autologous immune system, even in the presence of autoreactive T cells, pointing to several limitations that remain to be addressed for a model of spontaneous autologous SC-islet infiltration and destruction.
Authors
Camillo Bechi Genzano, Giorgia Zanetti, Qian Du, Daniel Traum, Deeksha Lahori, Grant M. Downes, Sakshi A. Bhatele, Xiaolan Ding, Kyle D. Apley, Rebuma Firdessa Fite, Matthew Ishahak, Enrique Eduardo Sanchez-Castro, Jeffrey R. Millman, Yiming Luo, Klaus H. Kaestner, Cory Berkland, Dieter Egli, Megan Sykes, Remi J. Creusot
