Figure 2.

Restraint stress impacts systemic glucocorticoid and immune circuits. Stressing pregnant dams (a) increased serum corticosterone and (b) upregulated expression of CRH in the hypothalamus and glucocorticoid receptor (NR3C1) in the amygdala (p = 0.099). Immunosuppression was indicated by reduced (c) spleen weights and relative concentration of splenic IL-1β, but not TNFα (p = 0.37). A general increase in CCR2 expression is demonstrated in (d) representative scatter plots of whole blood CD11b⁺CD45⁺Ly6G^-SSC^low mononuclear cells (Mo/M-MDSCs). When quantified, CCR2 expression increased within the mononuclear cell population as a whole, evidenced by (e) percent CCR2⁺ cells and CCR2 median fluorescence intensity (MFI). However, populations of mononuclear (f) Ly6C^-CCR2^- alternative M2 monocytes (p = 0.12), Ly6C^intCCR2^- transitional monocytes (p = 0.14), and Ly6C^hi CCR2⁺ classical M1 monocytes (p = 0.59) did not differ, nor were there overt differences in populations of circulating (g) CD11b⁺CD45⁺Ly6G⁺ polymorphonuclear cells (neutrophils or PMN-MDSCs; p = 0.21). Circulating plasma chemokine CCL2 concentrations (h) tended to decrease with stress (p = 0.056). Data are mean ± SEM, with each dot representing a single dam. NS = non-stressed, S = stressed; Mo/M-MDSCs = monocyte/monocytic myeloid-derived suppressor cells. CORT assay: n = 16/group; Spleen mass: n = 21–26/group; Spleen protein: n = 6–11/group; Gene expression: n = 7–10/group; Flow cytometry: n = 6/group. *p < 0.05, ^#p < 0.10.