Figure 8.

Jejunal tissue TGF-β downregulates monocyte cytokine production. (A) Culture supernatants from explants of jejunal mucosa cause dose-dependent downregulation of TNF-α and reciprocal upregulation of TGF-β release by monocytes. Monocytes were incubated with culture supernatant from explants of jejunal mucosa of increasing wet weight for 1 hour and then for 24 hours with LPS (1 μg/ml). Culture supernatants were harvested and analyzed for TNF-α and TGF-β protein. Values are mean ± SD (n = 2). (B) TGF-β Abs reverse the ability of jejunal mucosa culture supernatant to inhibit monocyte TNF-α release. Monocytes were incubated with increasing concentrations of anti–TGF-β Abs and jejunal mucosa culture supernatant and stimulated with LPS (1 μg/ml) for 24 hours. Supernatants were analyzed for TNF-α. Values are mean ± SD (n = 2).