Résumé : The aim of this study was to test the capacity of the novel adjuvant OM-174, a lipid A analog, to induce the migration and the maturation of murine dendritic cells (DC) in vivo, a step which is considered as the initiation of the adaptive immune response. BALB/c mice were injected intravenously or subcutaneously with OM-174. The spleen and popliteal lymph nodes were harvested, and analyzed for DC localization and phenotype. The data presented here clearly show that, OM-174 induces the migration of DC from the periphery to the T cell areas of lymphoid organs, and their maturation into cells expressing high levels of MHC class II and co-stimulatory molecules, with a potency close to that of Escherichia coli lipopolysaccharide (LPS).