Field Science Center, Graduate School of Agricultural Science, Tohoku University
Abstract
Recent interest has focused on the importance of intestinal immunity for the host defense, but to date, not much has been known about the underlying mechanisms. Toll-like receptor (TLR) family plays an important role in the defense through recognizing bacterial pathogen associated molecular patterns (PAMPs). Our research on the bioregulatory function of food products has investigated the immunoregulatory effects of lactic acid bacteria (LAB) via TLRs. Studies in swine, which is expected as a human model, have been examined intestinal immunoregulation by the LAB. Our research has now demonstrated modulation of intestinal immunity mediated by TLRs in Peyer\u27s patches and the mesenteric lymph nodes. On the basis of our study, efforts have also been made to develop an immunoassay system for immunobiotic LAB DNA and cell wall components to evaluate immunoregulation by the LAB via TLRs. The findings in our research activities may provide important clues at the molecular level on TLR signal transduction pathways and recognition mechanisms. They also provide impetus to further delineate the activation mechanism of the innate immune response. In addition, identification of biofactors from LAB with immunoactivity, and better understanding of cytokine induction and intestinal immune regulation hold promise in basic research and development of "immunobiotic foods" to prevent specific diseases
