Whole-genome CRISPR screening identifies genetic manipulations to reduce immune rejection of stem cell-derived islets

Human embryonic stem cells (hESCs) provide opportunities for cell replacement therapy of insulin-dependent diabetes. Therapeutic quantities of human stem cell-derived islets (SC-islets) can be produced by directed differentiation. However, preventing allo-rejection and recurring autoimmunity, without the use of encapsulation or systemic immunosuppressants, remains a challenge. An attractive approach is to transplant SC-islets, genetically modified to reduce the impact of immune rejection. To determine the underlying forces that drive immunogenicity of SC-islets in inflammatory environments, we performed single-cell RNA sequencing (scRNA-seq) and whole-genome CRISPR screen of SC-islets under immune interaction with allogeneic peripheral blood mononuclear cells (PBMCs). Data analysis points to alarmedpopulations of SC-islets that upregulate genes in the interferon (IFN) pathway. The CRISPR screen in vivo confirms that targeting IFNg-induced mediators has beneficial effects on SC-islet survival under immune attack. Manipulating the IFN response by depleting chemokine ligand 10 (CXCL10) in SC-islet grafts confers improved survival against allo-rejection compared with wild-type grafts in humanized mice. These results offer insights into the nature of immune destruction of SC-islets during allogeneic responses and provide targets for gene editing.

Automated summary

Human embryonic stem cells (hESCs) provide opportunities for cell replacement therapy, but preventing immune rejection remains a challenge. By studying the immune interaction of stem cell-derived islets (SC-islets) with peripheral blood mononuclear cells (PBMCs), researchers identified the interferon pathway as a major contributor to immune rejection. Targeting IFN-induced mediators improved SC-islet survival, and depleting CXCL10 enhanced survival against allo-rejection.