This paper provides a review of the role of dendritic cells (DC) in microparticle-mediated immune response and the advantages of associating DNA to microparticles in order to increase the potency of DNA vaccination in vivo. To begin with, different methods for the preparation of DNA-loaded microparticle with poly(lactide) (PLA)/poly(lactide-co-glycolide) (PLGA) polymers are presented. Further, the effects of DNA-loaded microparticles on DC in vitro are extensively examined including transfection and stimulation of DC, a key feature of the immune response. Finally, in vivo tracking of DNA-loaded microparticles and induction of immune responses upon DNA-loaded microparticle administration in different animal models and with various routes of administration are reviewed. (C) 2004 Elsevier B.V. All rights reserved.