Project Abstracts - CMAI

Robin Goland, MD, co-Investigator, Columbia University
Hans Snoeck, MD, PhD, co-Investigator, Columbia University
Nichole Danzl, PhD, co-Investigator, Columbia University
Yong-Guang Yang, MD, PhD, co-Investigator, Columbia University
Xiaojuan Chen, MD, PhD, co-Investigator, Columbia University
Dieter Egli, PhD, co-Investigator, Columbia University

Start Date: September 25, 2014
End Date: June 30, 2019

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Abstract

The study of autoimmune diseases such as Type 1 diabetes (T1D) has, until recently, been limited by the insufficiency of animal models and by the restriction of human patient samples to peripheral blood, which may not reflect immunity in the end organs. Moreover, patient populations are heterogeneous with respect to the duration of disease, treatments, comorbidities, genetic background and environmental exposures, making it difficult to identify pathophysiologic mechanisms. We have developed a “Personalized Immune” (PI) experimental mouse model that overcomes these limitations by allowing synchronized de novo development, in immunodeficient mice, of functional human immune systems from hematopoietic pluripotent cells of Type 1 diabetic (T1D) patients and healthy controls (HCs). T cells develop in human thymus grafts from CD34+ human pluripotent cells in cohorts of mice generated from a small bedside bone marrow aspirate. We now propose to develop this model further as an individualized model of human T1D biology, incorporating complete immune systems and pluripotent cell-derived β cells from the same T1D patient and healthy control donors. We have demonstrated in vivo function of β cells generated from iPSCs from skin fibroblasts of the same T1D patient and HC volunteers used to construct PI mice. We propose to further develop this model to induce β cell autoimmunity that attacks iPSC-derived β cells. We will:1) Optimize the functionality of human immune systems generated from adult human pluripotent cells by improving human APC repopulation and lymphoid structure and generating autologous thymic epithelial cells (TECs) from iPSCs derived from adult donors. Generation of TECs from iPSCs will provide autologous HLA/peptide complexes for positive selection of T cells that optimally interact with autologous APCs in the periphery. Readouts of immune function in all studies will include antibody, proliferative and cytokine responses to antigens used for immunization and ability to control EBV infections; 2) Optimize the use of iPSC-derived β cells as a target for autoimmunity in PI mice and compare the immunogenicity of T1D- vs HC-derived iPSC-derived β cells and of “natural” β cells. We will develop methods of enhancing the purity of iPSC-derived endocrine cells, optimize implantation methods and sites and characterize the immunogenicity of iPSC-derived endocrine cells that mature in vivo in comparison to adult human pancreatic islet β cells from T1D and HC subjects; 3) Develop an insulitis/diabetes model in PI mice. We will attempt to induce insulitis against the native pancreas and autologous iPSC-derived β cells in PI mice using a variety of manipulations. This optimized PI mouse will serve as a “gold standard” baseline in which to apply improvements in the ability to generate iPSC-derived β cells and human pluripotent cells, visualize immune interactions that initiate and drive T1D and assess environmental precipitants of disease. Through the Consortium, the model will allow analyses of both early and late events involved in T1D pathogenesis, and serve as a model to build upon as methods of expanding or generating human pluripotent cells from iPSCs and other technologies advance.

Publications

• ZnT8 Loss of Function Mutation Increases Resistance of Human Embryonic Stem Cell-Derived Beta Cells to Apoptosis in Low Zinc Condition
• T1D patient-derived hematopoietic stem cells are programmed to generate Tph, Tfh, and autoimmunity-associated B cell subsets in human immune system mice
• Defects in Long-Term APC Repopulation Ability of Adult Human Bone Marrow Hematopoietic Stem Cells (HSCs) Compared with Fetal Liver HSCs
• Modeling human T1D-associated autoimmune processes
• Use of Induced Pluripotent Stem Cells to Build Isogenic Systems and Investigate Type 1 Diabetes
• High Throughput Human T Cell Receptor Sequencing: A New Window Into Repertoire Establishment and Alloreactivity
• Human stem cell-derived thymic epithelial cells enhance human T-cell development in a xenogeneic thymus
• Role of the thymus in spontaneous development of a multi-organ autoimmune disease in human immune system mice
• Reduced replication fork speed promotes pancreatic endocrine differentiation and controls graft size
• Negative selection of human T cells recognizing a naturally-expressed tissue-restricted antigen in the human thymus
• How Safe Are Universal Pluripotent Stem Cells?
• Abnormal regulation of glucagon secretion by human islet alpha cells in the absence of beta cells
• Rapid thymectomy of NSG mice to analyze the role of native and grafted thymi in humanized mice
• Reduced positive selection of a human TCR in a swine thymus using a humanized mouse model for xenotolerance induction
• Crossreactive public TCR sequences undergo positive selection in the human thymic repertoire
• Pancreatic Beta Cell Differentiation From Human Pluripotent Stem Cells
• Quantifying size and diversity of the human T cell alloresponse
• Hypercholesterolemia induces T cell expansion in humanized immune mice
• HSC extrinsic sex-related and intrinsic autoimmune disease-related human B-cell variation is recapitulated in humanized mice
• β-Cell Replacement in Mice Using Human Type 1 Diabetes Nuclear Transfer Embryonic Stem Cells
• Type 1 diabetes induction in humanized mice
• Mechanisms of Mixed Chimerism-Based Transplant Tolerance
• Alloimmune T cells in transplantation
• Short-term High-fat Feeding Induces Islet Macrophage Infiltration and β-cell Replication Independently of Insulin Resistance in Mice
• A New Window into the Human Alloresponse
• Report from IPITA-TTS Opinion Leaders Meeting on the Future of β-Cell Replacement