Prostaglandin E2 (PGE2): Roles in Immune Responses and Inflammation

Abstract

Prostaglandins have numerous biologic effects on a variety of physiological and pathological activities such as inflammation, platelet aggregation, neurotransmitter release, smooth muscle contraction, and so forth. PGE2 is one of the well-studied inflammatory prostaglandins and causes vasodilatation, edema, fever and pain. Also PGE2 induces the production of matrix metalloproteinases (MMPs) which involve in destruction of tissue. In rheumatoid arthritis, macrophages isolated from patients secrete large amounts of PGE2 and PGE2 promote inflammation and participate in destructive mechanisms of the rheumatoid joint. In addition to its proinflammatory effects, PGE2 acts also as an immunomodulator, promote humoral and Th2-type immune responses and inhibit Th1-type immune responses. Also PGE2 inhibits the production of tumor necrosis factor (TNF-α), IL-1β, IL-8 and IL-12 and stimulates the production of IL-10 by macrophages. Thus PGE2 should be regarded not as proinflammatory molecule but as modulator of immune responses. In this review, we will focus on the current knowledge about PGE2 as the modulator of immune responses and summarize the effects of PGE2 on the immune systems and inflammation.