Type 1 Diabetes is caused by destruction of insulin producing beta-cells by autoimmune T-cells. Replacement of beta-cells through transplantation can supply new beta-cells, however these are at... Show moreType 1 Diabetes is caused by destruction of insulin producing beta-cells by autoimmune T-cells. Replacement of beta-cells through transplantation can supply new beta-cells, however these are at renewed peril of destruction through auto- and alloreactive immune responses. In this thesis, immune challenges, intervention strategies and biomarkers to guide treatment are investigated. Patient heterogeneity was identified as contributing factor to variations in efficacy of immune intervention therapies for type 1 diabetes. Immune infiltrations that matched with immune monitoring results were seen around islets transplanted to the liver of a patient. Cytokine and autoantibody immune markers were described that correlated with outcome of islet transplantation and combined kidney and pancreas transplantation. Immune consequences of tapering immune suppression after islet transplantation to minimize side effects were explicated. The immunological challenges that await beta-cells of alternative sources after transplantation, such as beta-cell lines and embryonic stem cells, were explored and pointed to need for immune protection and immune monitoring in early transplantation trials. These results support further investigation of immune intervention with disease specific immune modulation and beta-cell encapsulation strategies to achieve the desired drastic improvement in efficacy-risk balance for type 1 diabetes therapies. Show less