Immune system is sensitive to stress. Spleen is the largest peripheral immune organ innervated with sympathetic nerves and controlled by adrenomedullary system in the body. However, the alterations and mechanism of spleen immune cell subsets caused by repetitive restraint stress (RRS) is poorly understood. In this study, we found that RRS reduced spleen index in mice, and induced an expansion of white pulp and involution of the red pulp. Meanwhile, the percentage of CD3(+)CD8(+) T lymphocytes, CD11b(+)F4/80(+) macrophages, CD11b(+)Ly-6G(-)Ly-6C(hi) monocytic myeloid derived suppressor cells (mMDSCs) and CD11b(+)Ly-6G(+)Ly-6C(int) granulocytic myeloid derived suppressor cells (gMDSCs) in spleen were significantly changed by RRS. Mechanistically, we found that the expression of norepinephrine (NE) and beta-adrenergic receptor (beta-AR) in spleen were up-regulated after 21 days of RRS, but not 7 days. The expression of corticosterone (CORT) and glucocorticoid receptor (GR) in spleen were up-regulated after 7 days of RRS but were lower after 21 days of RRS, even though they were still higher than that in mice without stress. By treating the stressed mice with RU486 (antagonist of GR) or propranolol (antagonist of beta-AR), we demonstrated that GR was responsible for the changes of spleen induced by 7 days of RRS and beta-AR was for 21 days of RRS. Our data suggest that RRS changes spleen immune cell subsets through GR or beta-AR in a stage dependent manner. (C) 2017 Elsevier Inc. All rights reserved.