Immune-regulation and -functions of eicosanoid lipid mediators

Abstract

Bioactive lipids regulate most physiological processes, from digestion to blood flow and from hemostasis to labor. Lipid mediators are also involved in multiple pathologies including cancer, autoimmunity or asthma. The pathological roles of lipid mediators are based on their intricate involvement in the immune system, which comprises source and target cells of these mediators. Based on their biosynthetic origin, bioactive lipids can be grouped into different classes [e.g. sphingolipids, formed from sphingosine or eicosanoids, formed from arachidonic acid (AA)]. Owing to the complexity of different mediator classes and the prominent immunological roles of eicosanoids, this review will focus solely on the immune-regulation of eicosanoids. Eicosanoids do not only control key immune responses (e.g. chemotaxis, antigen presentation, phagocytosis), but they are also subject to reciprocal control by the immune system. Particularly, key immunoregulatory cytokines such as IL-4 and IFN-γ shape the cellular eicosanoid profile, thus providing efficient feedback regulation between cytokine and eicosanoid networks. For the purpose of this review, I will first provide a short overview of the most important immunological functions of eicosanoids with a focus on prostaglandins (PGs) and leukotrienes (LTs). Second, I will summarize the current knowledge on immunological factors that regulate eicosanoid production during infection and inflammation.

Eicosanoids in tissue repair

“…By the action of COX enzymes , which are the mechanistic targets of nonsteroidal anti‐inflammatory drugs (NSAIDs) including aspirin, AA is converted into prostaglandin (PG) H 2 , the precursor of all bioactive prostanoids (Figure ) (for a more detailed review of eicosanoid synthesis pathways see ). Prostanoids have highly diverse roles in pain, fewer and inflammation and they control hemostasis and vascular tone.…”

“…Eicosanoids [ είκοσι (Greek) = 20] are metabolites of polyunsaturated fatty acids (PUFAs) with 20 carbon atoms. Among the eicosanoids, metabolites of the ω‐6 PUFA arachidonic acid (AA) are particularly potent signaling molecules with important roles in inflammation and immunity (for a recent review see Reference #). Together with their immunological functions, eicosanoids are versatile mediators of tissue repair.…”

Fish Oil Can Significantly Reshape Diet-Based Gut Microbiota in Mice

“…Studies have also demonstrated bene cial immunomodulatory effects of ω-3 PUFAs, and the ratio of ω-3 and ω-6 PUFAs was shown to play an important role in in ammation by in uencing eicosanoid metabolism. [4] ω-6 PUFAs are metabolized into several proin ammatory mediators, while ω-3 PUFAs function as competitive inhibitors of enzymes and can be metabolized into several anti-in ammatory mediators. [4] Fish oil may have an indirect in uence on in ammation by modifying the gut microbiota.…”

“…[4] ω-6 PUFAs are metabolized into several proin ammatory mediators, while ω-3 PUFAs function as competitive inhibitors of enzymes and can be metabolized into several anti-in ammatory mediators. [4] Fish oil may have an indirect in uence on in ammation by modifying the gut microbiota. However, limited studies have investigated the in uence of sh oil on the gut microbiota, and the results are controversial, especially the observed changes in abundance of different bacteria.…”

Differential immune response to Eimeria maxima infection in fast‐ and slow‐growing broiler genotypes

“…only occurred in Ranger Classic broilers infected with either 2500 or 7000 oocysts on 13d pi. Eicosanoids, such as leukotrienes and prostaglandins, play an important role in many facets of the inflammatory immune response33 and COX-1 and COX-2 are required for the production of prostaglandins and thromboxanes (reviewed34 ). These findings may indicate that only the slow growing, Ranger Classic, are able to utilize these inflammatory mediators during E. maxima infection.…”