Secoemestrin C inhibits Con A-induced activation of NKT cells and conventional T cells in liver
The recruitment and activation of NKT cells and conventional T cells contribute remarkably to the development and progression of Con A-induced hepatic inflammation. To investigate whether secoemestrin C has any effect on lymphocyte subsets, we analyzed liver MNCs 8 h after Con A injection. As compared to the normal control group, the percentage of hepatic NKT cells in Con A-challenged mice was significantly decreased, whereas the percentages of conventional CD4+ and CD8+ T cells in the liver were relatively stable (Figure 5). Notably, secoemestrin C treatment largely rescued hepatic NKT cell depletion, as evidenced by a significantly increased ratio of hepatic NKT cells to liver MNCs in the treatment group when compared to that of the Con A-challenged group (Fig. 5A).
To determine whether secoemestrin C can suppress the activation of hepatic NKT cells and conventional T cells in vivo , we measured the expression of CD69 and IFN-γ by FACS analysis. Secoemestrin C treatment significantly inhibited the increase in CD69 expression on hepatic NKT cells and conventional CD4+ and CD8+ T cells that was seen in the Con A-challenged group (Fig. 6A, C). In addition, treatment with secoemestrin C also down-regulated the elevated expression of IFN-γ in hepatic NKT and conventional CD4+ T cells after Con A challengein vivo (Figure 6B, D).