Figure 4.

Gavage administration of 4,4′-diaponeurosporene-producing Bacillus subtilis (B.s-Dia) markedly increased intestinal epithelial cell (IEC)-derived CCL20 and reduced TGFβ production. (A,D) CMT93 cell was treated with 1 µM 4,4′-diaponeurosporene, 1 × 10⁷ colony forming units (cfu) B.s or B.s-Dia, the amounts of CCL20 in cultural supernatant were measured by ELISA. (B) Mice were intragastrically administrated of PBS, 1 × 10⁹ cfu B.s or B.s-Dia for 7 days, the expression of CCL20 (red) in IECs of the indicated mice were detected by confocal microscope. The staining of CD11c⁺ cells (green) were shown in below panels. Scale bar, 50 µm in above panel and 100 µm in the below panel. (C,E) The epithelial cell layer was digested as described in Section “Materials and Methods” and cultured for 6 h at 37°C. The amounts of cytokines CCL20 or TGFβ in cultural supernatant were measured by ELISA. (F) Mice were intragastrically administrated of PBS, 1 × 10⁹ cfu B.s or B.s-Dia for 7 days followed by Salmonella typhimurium gavage (Sty), and the production of IL-1β were detected as described in (C). One representative of three similar independent experiments is shown. Asterisks indicate statistical significance via the one-way ANOVA test (**P < 0.01, *P < 0.05).