Myeloperoxidase-halide system generates potent antimicrobial products within innate immunity

Mansour Bassiri

Department of Biological Sciences, NovaCal Pharmaceuticals, Inc. Emeryville, CA 94608

Innate immunity is the first line of defense against invading pathogens. The crosstalk between innate and adaptive immunity is known to produce sterilizing immunity for the host. A variety of endogenous agents, such as Reactive Oxygen Species (ROS), have been shown to be involved in the regulation of immune system via the cytokine network. Stimulated inflammatory cells (neutrophils, macrophages) are a rich source of large quantities of ROS. Herein, we have focused on the role of hypochlorous acid (HOCl) and Taurine chloramines (TauCl), the physiological products of neutrophils MPO-halide system, and demonstrate their potent antimicrobial properties. It is well documented that both HOCl and TauCl have broad spectrum antimicrobial activities, as well as pleiotropic effects on the inductive phase of the immune response. Based on literature review and our own research findings, we conclude that ROS not only protect host against invading pathogens, but also provide an important link between the innate and adaptive immunity.