To test whether the strength of immune reaction changes with the body’s sleep and wake cycles, researchers tracked the levels of expression of TLR9, a receptor that detects infection within a cell by binding to viral or bacterial DNA (1). Mice expressed more TLR9 at night (2), when the animals are most awake and active. Researchers also found that the TLR9 receptor production was ramped up with the help circadian clock proteins (3), which activated TLR9 gene transcription. PRECISION GRAPHICS EDITOR’S CHOICE IN IMMUNOLOGY
People often feel tired when they get sick, and researchers think that the cytokines helping fight infection may induce sleepiness. If immune-system activation can affect sleep, might the converse be true—do sleep cycles affect the immune system? Erol Fikrig and colleagues at the Yale University School of Medicine isolated some of the molecular players in both the circadian and the innate immune systems. They showed that the strength of some immune responses was indeed affected by the time of day.
To read the full, original article click on this link: A Good Night’s Sleep | The Scientist
