Seven laboratories (53 full-time researchers, plus 49 engineers and technicians), localized in the Pasteur Institute of Lille (France) and linked by the concern of understanding the molecular and cellular mechanisms of the pathogenesis of bacterial, viral, parasitic and inflammatory diseases, define new criteria for immunogen selection and therapeutical targets, and for safer and more effective strategies in human therapy against these pathologies. They investigate pathogenic factors and their regulation (cell adhesion molecules, cytokines and chemokines) in the host-pathogen relationships. These laboratories cover: A-"Schistosomiasis, Malaria and Inflammation". B-"Cellular mechanisms of the inflammatory reaction in immunoallergic and respiratory pathology", C-"Molecular mechanisms of bacterial pathogenesis", D-"Bacteriology of ecosystems", E-"Ecology of parasitism", F-"Molecular and cellular interactions of pathogenic bacteria with their hosts" and G-"DNA micro array". They have also a common interest and collaborative research in mucosal immunity. The site offers the overall panel of up-to-date technologies in molecular and cell biology, immunology and genetics, in the analysis, design and manufacturing of new molecules, and in the production and development of transgenic animals. This group of laboratories has allowed the submission and success of more than 70 doctoral thesis between 1994 and 2000, for postgraduate students from 12 different countries. Its links with Lille universities (Medical School and Science University), a constant interaction with clinical departments in the hospital, a doctoral training with the Universite Libre of Brussels, the organization of seminars and conferences with researchers of international reputation, the participation of post-graduate students to scientific meetings where they can present their results, all these facilities offer to post-graduate students a high level of training and improvement of competence.