抄録
There is abundant evidence that lactoferrin (LF) influences various immune functions. Recent reports have shown enhancement of anti-microbial, anti-viral and anti-tumor immune activities after oral administration. We report here that orally administered bovine LF (bLF) increases numbers of peripheral NK cells and augments NK cell activity. When poly(I:C) i.p. injection induced NK cell trafficking into peritoneum, additional bLF oral administration increased NK cell accumulation. Oral administration of bLF immediately induced the production of IL-18 in the intestinal epithelium, and elevation of portal IL-18 levels. In IL-18 KO mice, oral bLF did not increase the numbers of NK cells, although NK cell cytotoxic activity and poly(I:C) induced trafficking activity were both enhanced . Furthermore, oral bLF administration augmented the expression of type-I IFNs in Peyer's patches and mesenteric lymph nodes. Collectively, these results indicate that orally administered bLF stimulates intestine-associated immune functions, including the production of IL-18 and type-I IFNs, and then raises NK cell activity.
