A research group led by Professor Koichi Ikuta of Kyoto University, in collaboration with Osaka University, Kyushu University, and the German Cancer Research Center, conducted diurnal fluctuations in the internal circulation and immune response of T lymphocytes, which are responsible for immunity. It was revealed that it controls and enhances immunity.
Glucocorticoid (a type of steroid hormone) has a strong immunosuppressive effect and is used as an anti-inflammatory agent and an immunosuppressive drug for the treatment of various diseases.Its concentration fluctuates daily, but its relationship to immune function was unclear.
The research group focused on diurnal fluctuations in glucocorticoid concentration and analyzed changes in mouse T lymphocytes (a type of lymphocyte) at each time of the day.As a result, it was found that glucocorticoids increase the expression level of certain receptors for T lymphocytes (cytokine receptor IL-7R and chemokine receptor CXCR4) at night and lower them during the day.It was also found that the diurnal variation causes diurnal variation in the distribution of T lymphocytes that stay in the blood during the day and collect in the lymphoid tissue at night.Furthermore, it was found that the collection of T lymphocytes in the lymphoid tissue at night activates the lymphocytes more efficiently and triggers a strong immune response.
From the above results, it was clarified that glucocorticoid, which is famous for its immunosuppressive action, has a function of enhancing immune function by controlling the diurnal variation of T lymphocyte circulation and response in vivo. ..
This result suggests that disturbance of glucocorticoid secretion due to irregular life may lead to a decrease in immunity.Furthermore, it is expected that the relationship between diurnal variation and immune abnormalities such as allergies such as bronchial asthma and autoimmune diseases such as rheumatoid arthritis will be elucidated in the future.
Paper information: [Immunity]Glucocorticoids Drive Diurnal Oscillations in T Cell Distribution and Responses by Inducing Interleukin-7 Receptor and CXCR4 (PDF)
