Virus infections are a major cause of diseases and death among men and animals. The recent outbreak of SARS and the danger that an avian influenza virus may become pandemic, have clearly shown that members of any virus family can potentially turn into a pathogen. To combat virus infection and propagation, systematic and comprehensive studies both on viral components mediating virus-cell interactions, and on the cell biology behind virus entry are necessary. Our network, teaming academic and industrial groups, is aimed at undertaking an interdisciplinary effort to reveal the diversity of pathways and associated molecular mechanisms of cell entry of enveloped viruses. Research by experimental and theoretical approaches will be directed towards the identification of cellular receptors and of viral fusion proteins responsible for interaction with host cells. Among topics are folding, three-dimensional structure and conformational changes of viral fusion proteins as well as virus triggered signalling cascades in cells. Biophysical approaches will unravel the relationship between energetics of conformational changes of viral proteins and membrane bending and fusion. Together with industrial partners the project will identify potential targets for designed drug development, and will develop virus protein coated nanoparticles as new biotechnological and medical tools. The groups have complementary expertise at the highest standard in all required techniques of virology, molecular and cellular biology, biochemistry, proteomics, structural biology, theoretical and experimental biophysics. A challenging research and training environment in an international setting will provide young scientists with a network wide research-oriented training devoted to the specific aspects of virus entry and to structuring of industry projects and commercial exploitation of results, and a local training in soft skills and basic complementary education adapted to the personal needs.