Abstract

Circadian rhythms are a ubiquitous feature of all living organisms, and in animal species are involved in the regulation of a wide diversity of physiological systems. It has long been established that the circadian clockwork plays a key role in innate immune responses, with more recent studies now revealing that several aspects of adaptive immunity are also under the control of the circadian clock. The circadian clockwork is driven by a small number of conserved genes, which operate as a rhythmic transcriptional/translational feedback loop, and are inter-locked to output circuits with the cell. In animal models, mutations of these elements in immune cells commonly lead to disrupted immunity and defense, while in humans, environmental disruption of circadian rhythms (ie shift-work) leads to perturbed immune function. I will discuss recent finding showing how the genetic and biochemical mechanisms linking immunity to the core circadian clock of the cell operate. A key question is why the immune system is so tightly controlled by circadian oscillations, and what are the implications for human health including vaccination strategies within the emerging field of chrono-immunology.