Illness caused by bacterial infections is a major burden on the health care system and leads to significant economic loss through sick leave. The steady emergence of antibiotic resistant pathogen strains emphasises the necessity of maximising the defensive potential of natural immunity. In recent years there have been tremendous advances in understanding the ways in which the adaptive immune system deals with pathogens and there have been equally rapid advances in understanding the ways in which the so-called innate immune system holds infections in check. It is now clear that the two systems, far from being independent, are in fact tightly intermeshed so that a host pathogen interaction always involves components from both systems. Indeed it is at this interface between innate and adaptive immunity that the central decisions are taken which determine whether the host's attempts to fend off bacterial attack will succeed. Despite our increased understanding of the coordinated nature of the host response, attempts to develop new therapeutic strategies based on these insights have so far been disappointing.
The cause of these failures can in part be traced to the fact that innate and adaptive immunity have till now been largely treated as quite different subjects of investigation. As a consequence no major conferences are currently staged in Europe, which are directed to integrating our concepts of these two aspects of defence strategy. The objective of the proposed meetings is to provide a forum within which internationally recognised experts from both sides of the problem will discuss the mechanisms operating at the interface between innate and adaptive immunity. A better understanding of these mechanisms and their coordination will be essential in order that ways can be developed to manipulate the system to the patient's advantage.