Fermented food Tempeh induces interleukin 12 and enhances macrophage phagocytosis.

It is known that lactic acid bacteria induce the IL-12. The IL-12 activates NK cells and promotes the production of IFN-γ. The IFN-γ activates macrophages resulting in enhanced phagocytosis and bactericidal activity. We have been investigating fermented foods that activate the immune function. In this study, we investigated the IL-12 inducibility of fermented foods using the specific antibody. Fermented soybean foods such as Tempeh and Natto are attracting attention in terms of nutrition, functionality, and food problems. In this study, Tempeh induced 1,080 µg/ml of IL-12, and IFN-γ associated with the induction of IL-12 was also induced at 682 µg/ml. This was more than twice the induced intensity of PBS. On the contrary, Natto hardly induced IL-12 and IFN-γ. Tempeh also accelerated phagocytosis of the macrophage THP-1 cells. In this study, it was found that the fermented soybean-derived food, Tempeh, has a function of activating the immune function. This is the first report that Tempeh activates innate immunity. PRACTICAL APPLICATIONS: Tempeh, a fermented soybean food induced the IL-12 and IFN-γ production and the increase of macrophage phagocytosis in this study suggested a new function to enhance immunity. Tempeh is also expected to be effective in preventing lifestyle diseases. Fermented soybean products of Tempeh was considered to be a very useful health food for the problems of modern society such as maintaining health by eating, improving immunity, and ingesting vegetable protein due to diversifying food.

Biochemical properties of human full-length aryl hydrocarbon receptor (AhR).

The aryl hydrocarbon receptor (AhR) is a very unstable protein. AhR binds to the molecular chaperone complex (HSP90-p23-XAP2) to maintain a stable structure in the cytoplasm. After binding to ligands, such as dioxin, AhR translocates from the cytoplasm to the nucleus with a molecular chaperone complex. The protein forms a heterodimer with Arnt after nuclear transfer, functions as a transcription factor by binding to a xenobiotic responsive element (XRE), and induces the cytochrome P450 1A1 (CYP1A1). Because of the unstable protein, expression of the full-length AhR in the E. coli expression system is very difficult. Many studies investigated AhR using AhR domains in vitro. We expressed and purified the human full-length AhR in E. coli expression system. Furthermore, specific antibodies were prepared. Purified full-length AhR could bind to ligand. In the presence of ligand, α-helix and random coil of AhR increased and ß-sheet decreased on CD spectrum. Full-length AhR could bind to HSP90, XAP2 and p23 in the presence or absence of ligand. We now show the biochemical properties of full-length AhR.