Role of Plasma Membrane Redox Activities in Immune Response Mechanisms

The plasma membrane redox system (PMRS) is an important component of the cell's ability to defend itself against oxidative stress. Many immune signaling pathways are regulated through redox reactions. Biological systems utilize oxidationreduction reactions to modulate their responses to environmental cues. The role of redox molecules such as NO and ROS as key mediators of immunity has recently gathered a lot of interest and attention. Beyond the chemical interactions of NO and ROS that combine to eradicate pathogens, these redox small molecules are effective immune-modulators that regulate cellular metabolism as well as multiple pro-inflammatory and repair/tissue-restoration pathways. Redox molecules such as peroxide, superoxide, NO, and RNS, once thought to be only toxic, are essential in tissue repair. These species are generated, converted and metabolized during host microbe interaction involving the innate immune system. Cytochrome b558 is the flavin binding component of the NADPH oxidase. NADPH oxidases are key producers of ROS. A variety of RNS and ROS is produced in the acidic mileu of phagosomes, which provide an environment conducive to the redox chemistry, which is the first line in fighting infection. Bacterial cell immune response also involves NO. Thus understanding the plasma membrane redox activities can help unravel the mechanisms of immune response. Keywords: Plasma membrane, Redox activities, oxidative stress, NO, ROS, RNS. Nitrous Oxide, Reactive Oxygen Species, Reactive Nitrogen species.