Dendritic Cells and Macrophages: Same Receptors but Different Functions

Dendritic cells (DCs) and macrophages differently contribute to the generation of coordinated immune system responses against infectious agents. They interact with microbes through germline-encoded pattern-recognition receptors (PRRs), which recognize molecular patterns expressed by various microorganisms. Upon antigen binding, PRRs instruct DCs for the appropriate priming of natural killer cells, followed by specific T-cell responses. Once completed the effector phase, DCs reach the terminal differentiation stage and eventually die by apoptosis. By contrast, following antigen recognition, macrophages initiate first the inflammatory process and then switch to an anti-inflammatory phenotype for the restoration of tissue homeostasis. In this review we will focus on the comparison of the divergent responses of DCs and macrophages to microbial stimuli and in particular to lipopolysaccharide (LPS).