β2-adrenergic receptor modulation of macrophage inflammatory mediator production

Research has demonstrated that the complex interaction between the nervous system and the immune system plays a critical role in maintaining homeostasis. The nervous system is capable of modulating the immune response via activation of β2-adrenergic receptors (β2-ARs) present on immunocompetent cells. Because macrophages are major mediators of the immune response, several investigators have sought to determine the effect of β2-AR stimulation upon inflammatory mediator production by these cells. Traditionally, scientists have regarded β2-AR activity as anti-inflammatory since stimulation of these receptors inhibits LPS-induced production of inflammatory molecules. However, a thorough review of existing literature reveals several publications suggesting β2-AR activation may actually have pro-inflammatory effects upon macrophage response. Importantly, β2-AR drugs are often used to treat various diseases, including several diseases of inflammatory origin. As a result, recognizing the dual immunomodulatory potential of β2-ARs is necessary to fully understand the inflammatory impact of β2-AR drugs in therapy