Glucocorticoids Drive Diurnal Oscillations in T Cell Distribution and Responses by Inducing Interleukin-7 Receptor and CXCR4

Publication date: 20 February 2018
Source:Immunity, Volume 48, Issue 2
Author(s): Akihiro Shimba, Guangwei Cui, Shizue Tani-ichi, Makoto Ogawa, Shinya Abe, Fumie Okazaki, Satsuki Kitano, Hitoshi Miyachi, Hisakata Yamada, Takahiro Hara, Yasunobu Yoshikai, Takashi Nagasawa, Günther Schütz, Koichi Ikuta
Glucocorticoids are steroid hormones with strong anti-inflammatory and immunosuppressive effects that are produced in a diurnal fashion. Although glucocorticoids have the potential to induce interleukin-7 receptor (IL-7R) expression in T cells, whether they control T cell homeostasis and responses at physiological concentrations remains unclear. We found that glucocorticoid receptor signaling induces IL-7R expression in mouse T cells by binding to an enhancer of the IL-7Rα locus, with a peak at midnight and a trough at midday. This diurnal induction of IL-7R supported the survival of T cells and their redistribution between lymph nodes, spleen, and blood by controlling expression of the chemokine receptor CXCR4. In mice, T cell accumulation in the spleen at night enhanced immune responses against soluble antigens and systemic bacterial infection. Our results reveal the immunoenhancing role of glucocorticoids in adaptive immunity and provide insight into how immune function is regulated by the diurnal rhythm.

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Teaser

Glucocorticoids have strong immunosuppressive effects, yet their physiological functions in the immune system remain unclear. Shimba et al. demonstrate that glucocorticoids drive IL-7R expression in a diurnal fashion, which induces the redistribution of T cells between peripheral blood and lymphoid organs via CXCR4 expression and enhances adaptive immune responses.


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