5-Lipoxygenase Pathway, Dendritic Cells, and Adaptive Immunity

5-lipoxygenase (5-LO) pathway is the major source of potentproinflammatory leukotrienes (LTs) issued from the metabolism ofarachidonic acid (AA), and best known for their roles in thepathogenesis of asthma. These lipid mediators are mainly releasedfrom myeloid cells and may act as physiological autocrine andparacrine signalling molecules, and play a central role inregulating the interaction between innate and adaptive immunity. The biological actions of LTs including their immunoregulatoryand proinflammatory effects are mediated through extracellularspecific G-protein-coupled receptors. Despite their role ininflammatory cells, such as neutrophils and macrophages, LTs mayhave important effects on dendritic cells (DC)-mediated adaptiveimmunity. Several lines of evidence show that DC not only areimportant source of LTs, but also become targets of their actionsby producing other lipid mediators and proinflammatory molecules.This review focuses on advances in 5-LO pathway biology, theproduction of LTs from DC and their role on various cells ofimmune system and in adaptive immunity.