Cultivating our "Frienemies": Viewing immunity as microbiome management

Immunology has been studied and understood in the context of the compelling problems of infectious disease. But our rapidly growing knowledge of immune interactions with our healthy microbiota, and the many benefits it confers, suggests there may be value to an alternative view: that mechanisms of defense against pathogens are one aspect of a complex system with the broader purpose of managing our healthy microbiome. From this perspective, adaptive immunity may be viewed as a flexible system for simultaneously recruiting and managing a near limitless number of potential symbionts. This perspective can allow for reinterpretation of many observations and can suggest new experiments to help us better understand our complex interactions with the microbes that surround us.