Koizumi Shin-Ichi, Wakita Daiko, Sato Tomomi, Mitamura Rieko, Izumo Takayuki, Shibata Hiroshi, Kiso Yoshinobu, Chamoto Kenji, Togashi Yuji, Kitamura Hidemitsu, Nishimura Takashi
Division of Immunoregulation, Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815, Japan.
Immunol Lett. 2008 Oct 30;120(1-2):14-9. doi: 10.1016/j.imlet.2008.06.003. Epub 2008 Jul 11.
Activation of type 1 immunity plays a critical role in host defense mechanisms against infectious disease and tumor. Lactic acid bacteria, existing in the gastrointestinal tract, are one of the powerful tools to induce a type-1-dominant immunity, which may improve Th2-dependent allergic diseases. In the present work, we found that an oral intake of Lactobacillus pentosus strain, S-PT84 into mice significantly enhanced NK activity of spleen cells in vivo. We further revealed that NK1.1 positive NK cells and NKT cells are responsible cells for producing IFN-gamma after stimulation with S-PT84 in vitro. S-PT84 induced IFN-gamma-producing cells through activation of IL-12 production by CD11c(+)DCs in Toll-like receptor (TLR) 2- and/or TLR4-dependent manner. Interestingly, direct interaction between DCs and NK1.1(+) cells was also essential for the IFN-gamma production in response to the S-PT84 stimulation. Therefore, we concluded that S-PT84 effectively promoted type 1 immunity through IL-12 and IFN-gamma which were produced by DCs and NK1.1(+) cells, respectively. Thus, S-PT84 would be a nice immune modulator for improving immunobalance, which plays a pivotal role for controlling allergy, infectious diseases and tumor.
1型免疫的激活在宿主抵御传染病和肿瘤的防御机制中起着关键作用。存在于胃肠道中的乳酸菌是诱导1型主导免疫的有力工具之一，这可能改善Th2依赖性过敏性疾病。在本研究中，我们发现给小鼠口服戊糖乳杆菌菌株S-PT84可显著增强体内脾细胞的NK活性。我们进一步揭示，NK1.1阳性NK细胞和NKT细胞是体外经S-PT84刺激后产生IFN-γ的责任细胞。S-PT84通过以Toll样受体（TLR）2和/或TLR4依赖性方式激活CD11c(+)DCs产生IL-12来诱导产生IFN-γ的细胞。有趣的是，DCs与NK1.1(+)细胞之间的直接相互作用对于响应S-PT84刺激产生IFN-γ也至关重要。因此，我们得出结论，S-PT84通过分别由DCs和NK1.1(+)细胞产生的IL-12和IFN-γ有效促进1型免疫。因此，S-PT84将是一种改善免疫平衡的良好免疫调节剂，而免疫平衡在控制过敏、传染病和肿瘤方面起着关键作用。
