The Cell Biology and Immunology group has directed its research at health problems in general, and the immune system in particular by studying the recognition and inactivation of potential hazardous material, e.g. pathogens. The expression and function of different immune cells and a variety of cell-bound(specific receptors, MHC molecules) and soluble factors (immunoglobulins, cytokines) are studied in immune reactions. This approach is also important for the evaluation of resistance against infectious diseases. One of the hallmarks of our research program is the extensive MHC variability and the presentation of peptides derived from infectious agents for their association with the capacity to mount a protective immune response. This has been made possible since the MHC complex and its genetic polymorphism have been characterized and sequenced in carp (Cyprinus carpio)as an animal model system. Another research line comprises the effects of stress on neuro-endocrine regulation and the regulatory role of cytokines in specific immune responses. Special focus is on the mucosal immune system in fish. These results can be applied by using genetic selection to increase disease resistance and understanding the impact of environmental factors on the adaptive capacity of the immune system to maintain health in various species. Additionally, novel insights in the field of biotechnology will lead to the generation of new reagents (monoclonal antibodies; single chain Fv fragments; cytokines) and techniques (automated gene sequencing; reverse transcription polymerase chain reaction (RT-PCR); peptide loading, elution, andsequencing; biosensor technology). Ultimately, new vaccines for diseases in fish and shrimp (Penaeus monodon) can be rationally designed based on the insights obtained.