ABSTRACT
Objective:To investigate the impact of dexamethasone on the balance of natural regulatory T cells(nTreg) and typeⅠ regulatory T cell(Tr1) in vitro.Methods:Peripheral blood lymphocytes(PBMCs) recruited from healthy donor,divided into dexam-ethasone stimulus group and negative control group.After 3 days treatment,cells were stained.The expression of CD25,CD127, Lymphocyte-activation 3 (LAG-3) and Forkhead box P3 (Foxp3) and frequency of Treg and Tr1 were analyzed by flow cytometry.Results:Compared to the control group,after stimulation with dexamethasone for 3 days,the percentage of CD4+T cells increased in a dose-dependent manner.The expression of CD25 and Foxp3 in CD4+T cells decreased significantly (P=0.006, P<0.000 1),while CD127 and LAG-3 expression increased significantly in CD4+T cells (P<0.000 1,P=0.011).Dexamethasone treatment significantly enhance the frequency of Tr1(P=0.051),reduce the frequency of Treg (P<0.001),and the ratio of Tr1/Treg also increased(P=0.044).Conclusion:Short-term treatment with dexamethasone in vitro change the balance of natural regulatory and type Ⅰ regulatory T cells.
ABSTRACT
<p><b>OBJECTIVE</b>To explore the possible mechanism of the inhibitory effect of liver X receptor alpha (LXRalpha) on lipopolysaccharide (LPS)-induced inflammation in mouse Kupffer cells (KCs).</p><p><b>METHODS</b>The KCs isolated from the liver of male KM mice and cultured in RPMI 1640 containing 20% FBS for 24 h were divided into control, LPS, T0901317, and LPS+T0901317 groups with corresponding treatments. The expressions of LXRalpha, interferon regulatory factor 3 (IRF3) and glucocorticoid receptor interacting protein 1 (GRIP1) in the KCs were detected by Western blotting. The levels of interferon beta (IFNbeta), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in the supernatant were detected by enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>The level of LXRalpha protein was highest in T0901317 group and lowest in LPS group, and was significantly higher in LPS+T0901317 group than in LPS group but lower than in T0901317 group (P<0.05). The levels of IRF3 and GRIP1 protein were the highest in LPS group, and significantly lowered by T0901317 treatment (P<0.05). The expression of IRF3 and GRIP1 proteins in LPS group and LPS+ T0901317 group were significantly higher than those in the control and T0901317 groups (P<0.05). The concentration of IFN-beta was significantly higher in LPS group than in the control and T0901317 group (P<0.05), and decreased in LPS+T0901317 group in comparison with that in LPS group (P<0.05). IFN-beta was the lowest in T0901317 group. The levels of TNF-alpha and IL-1beta were the highest in LPS group (P<0.05), and comparable between the other 3 groups (P>0.05).</p><p><b>CONCLUSION</b>Pre-treatment with T0901317 before LPS stimulation can suppress the expressions of IRF3 and GRIP1 to inhibit the inflammation and hence Kupffer cell activation.</p>