The scope of the current thesis is to obtain insight in immunological aspects of transplantation and diabetes. This thesis underscores the current concept of collaboration between the innate and adaptive immune system by showing close interactions between both immune systems. Mannose binding lectin as a major recognition molecule of the lectin pathway and as a key protein of the immune system was studied in relation to its functional characteristics. Appreciating the Jekyll-and-Hyde character of MBL and the fact that MBL serum levels and functionality are under strict genetic control, MBL was studied under distinct pathological conditions. Chapter 2 describes molecular and biological aspects of mannose binding lectin and the interaction of MBL with the adaptive immune system. Chapter 3 focuses on the involvement of MBL in autoimmunity, by studying juvenile type 1 diabetic patients at disease onset. Chapter 4 addresses the role of the liver in production of serum MBL and evaluates the effect of MBL variant alleles on the susceptibility to infection after liver transplantation. Chapter 5 focuses on the effect of the adaptive immune system on islet transplantation, a novel treatment of type 1 diabetes.LEI Universiteit LeidenImmunogenetica en cellulaire immunologie van auto-immuunziekten
