The introduction of new technologies of Cellular Biology, Biochemistry and particularly of the Molecular Biology have been made possible that most of our concepts have been changed in a science that is mostly experimental. All of this requires a continuous update. The fact that to study immunology a large variety of technologies is required, made that the interest of this symposium is not only limited to the immunologists but also to other professionals in common interests such as biochemist, cellular biologist, pharmaceuticals, clinicians, physiologist, etc. It is for this reason that this symposium may be an excellent source of information for all these people and will be useful to update their knowledge, based on the personal experience of the speakers of this symposium, and the new concepts in this scientific field.

The immunology is not only a theoretical science with many applications, but also includes the interaction with the patients, where immunology is a critical instrument in areas such as transplants, immune deficiencies, or autoimmune diseases. The industries have an interest for immunology that is growing each day. The production of monoclonal antibodies or citokines plays an important role in Biotechnology. We cannot forget the fascinating world of vaccines, that allowed to erradicated virus diseases such as smallpox and is the hope for diseases such as AIDS or to eliminate diseases that affect to animals. In this symposium we will discuss the advances that have been produced in the last years in the receptors of the cells of the immune system that play a key role in the immune responses.

Over the last years, through the progress in the study of the genome a large number of receptors both in myeloid and lymphoid cells have been described. Many of these receptors induce cellular activation while others induce cellular inhibition. What determine the response of the cell when there are so many receptors many of them bindings to the same ligands? It is logical to believe that the understanding of these receptors is critical at the moment to elaborate reagents or drugs that modulate their functional capacities and thus to have a therapeutic utility. There is no doubt that the challenge to understand what is going on around the cells is very exciting and because of the quality of the speakers and the subjects treated during the symposium, new avenues and perspectives will be open for the research in the field.

This symposium is recognized as a course of Ph.D. program of Immunology by the University of Barcelona and the Autonomous University of Barcelona.