Immunomodulation against microbial pathogens through dendritic cells

Dendritic cells (DCs) are the most potent antigen presenting cells (APCs), being a key player in the regulation of the adaptive immune response. These immune cells are in their immature form in circulation and peripheral tissues, being able to take up, process and activate the antigen-presenting pathway by the interaction of antigen-loaded Major Histocompatibility Complex molecules class I (MHC class I) and II with, respectively,CD4+ and CD8+ T cells, which will then stimulate Cytotoxic T Lymphocytes (CTL) and Th cells. As a result, this heterogeneous population, present in lymphoid and nonlymphoid organs, is fundamental to survey tissues for foreign antigens and thus to induce an effective immune response, but also, on the other hand, to maintain tolerance against self or harmless antigens. In this review we will explore the interplay between DCs subpopulations and microbial pathogens, highlighting their role as regulators in health and infectious diseases. In addition, we will emphasize progress in our understanding of immunomodulatory strategies, namely those based on nanodelivery systems used to promote host protection through the delivery of antigens to DCs and their presentation to T-cells, being these important factors to have in consideration when developing an effective vaccine