Figure 7
Binding of iSEC1 to CD200R on IELs attenuates their cytokines production and cytolytic activity in vitro.
(a) IL-2-cultured IELs were stained with anti-CD200R, CD200-IgFc, or iSEC-IgFc. A shaded histogram shows staining with isotype-matched control antibody, and dashed histograms show staining with control IgFc. (b) IL-2-cultured IELs were starved of IL-2 for 3 h and left unstimulated or stimulated for 24 h with plate-bound anti-CD3 in the presence of plate-bound mock IgFc, CD200-IgFc or iSEC1-IgFc, followed by measurement of indicated cytokines in their culture supernatants (mean ± SEM, n = 3). (c–e) IL-2-cultured IELs were incubated at the indicated effector/target (E/T) ratios for 48 hrs with plate-adherent CT-26 transfectants expressing GFP together with mock control, CD200R, CD200, or iSEC1. (c) Shows photographs of GFP-expressing CT-26 transfectants (at the 8:1 E/T ratio) taken after the 48 h-cytolysis culture under fluorescence microscope. Cytolysis of CT-26 cells in monolayer culture resulted in detachment and aggregation of cells, as typically observed in mock transfectants (top panel). In (d) % lysis of CT-26 transfectants in each group was calculated (mean ± SEM, n = 3). In (e) supernatants were harvested from the 48 h-cytolysis culture at the 4:1 E/T ratio, and analyzed for the concentration of indicated cytokines (mean ± SEM, n = 4). Data in (a–e) are representative of at least three independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001.
