Inhibition of Aberrant Circulating Tfh Cell Proportions by Corticosteroids in Patients with Systemic Lupus Erythematosus
Figure 4
Decreased CXCR5+ PD1+/CD4+ cell production by dexamethasone.
A. Dexamethasone (Dex) reduced the proportion of IL-21 stimulated CXCR5+ PD1+/CD4+ cell. Each line represented the alterations of CXCR5+ PD1+/CD4+ cell percentages of an individual sample when cultured with medium control, IL-21 or IL-21+ Dex for 24 hours in vitro. Paired t-test was applied to compare results between two groups and Kruskal-Wallis test was used to determine the difference among three groups. Compared with control group, CXCR5+ PD1+/CD4+ cells were increased when cultured with IL-21 (p<0.01). Adding dexamethasone to IL-21 culture system significantly inhibited the production of CXCR5+ PD1+/CD4+ cells (p<0.0001). B. A similar tendency was observed when cells were cultured for 72 hours. Each line represented the alterations of CXCR5+ PD1+/CD4+ cell percentages of an individual sample. C. Dexamethasone reduced the proportion of CXCR5+ PD1+/CD4+ cell in a dose-dependent manner. Each line represented the changes of CXCR5+ PD1+/CD4+ cell percentages of an individual sample when cultured with different concentrations of dexamethasone for 24 hours in vitro and paired t-test was applied to compare results between two groups. D. Downregulation of CXCR5+ PD1+/CD4+ cell by dexamethasone was not a consequence of the decline in total cell numbers. Cells were equally divided into 3 groups to culture with different concentrations of dexamethasone. After 24 hours culturing, all the cells were harvested and counted by flow cytometry. There were no differences of total cell numbers among the groups (p>0.05). E. Increased cell apoptosis after dexamethasone treatment. PBMCs from 6 SLE patients were collected and cultured in the presence or absence of dexamethasone for 24 hours. Then cells were harvested and quantified by FACS. Data were shown as mean ± SEM. The percentages of Annexin V+ cells are much higher in CXCR5+ PD1+/CD4+ groups, especially for those treated with high dose dexamethasone.