Taken together, ICG-001 these results provide evidence that JWS 833 has

an immune-enhancing effect on mice infected with Listeria and that this effect is remarkably greater than that mediated by LGG. We found that JWS 833 enhances murine immune responses to bacterial infection. Based on these findings, we conducted further experiments to assess whether JWS 833 protects mice after they have been infected with L. monocytogenes. All the mice in the PC and LGG-fed groups died within 150 hrs of being infected with L. monocytogenes at a lethal dose, 1.2 × 105 cfu (Fig. 3). However, administration of JWS 833 strain at 1 × 109 cfu/day reduced the morbidity and mortality caused by L. monocytogenes infection. The immuno-enhancing effects of JWS 833 strain may protect mice, reducing the morbidity and mortality of listeriosis. Thus, our results suggest that JWS 833 isolated from duck intestine is Bafilomycin A1 chemical structure a potential immunomodulator and facilitates suppression

of L. monocytogenes infection. We examined the immune-enhancing properties of JWS 833 isolated from duck intestines by measuring production of NO and inflammatory cytokines in mouse peritoneal macrophages and infected mice. We compared the effects of JWS 833 with those mediated by LGG, a bacterial strain known to have immunomodulatory properties. Our in vitro experiments showed that JWS 833 stimulates production of NO, IL-1β and TNF-α by mouse peritoneal macrophages. This effect was greater tetracosactide than that induced by LGG. We used heat-killed LAB (JWS 833 and LGG) in in vitro experiments to prevent

macrophage cell death caused by bacterial overgrowth and low acid conditions. Heat-killed LAB induce cytokines production by activating macrophages (20, 21) and studies show that heat-killed LGG cells are as effective as viable cells (19). Various studies have reported that LAB protect mice against pathogens. Administration of Lactobacillus rhamnosus increases the survival of mice infected with Salmonella Typhimurium (22), and Lactobacillus casei induces resistance to L. monocytogenes infection in mice or rats (23, 24). E. faecium also increases the production of anti-Salmonella antibodies in a Salmonella enterica infection model (25) and enhances the murine immune response to Giardia intestinalis (15). Cheers and Mckenzie reported BALB/c mice were most susceptible to L. monocytogenes (28) and Puertollano et al. (29) and Paturi et al. (30) used BALB/c mice to evaluate immune responses of LAB. We used BALB/c mice in our study because the L. monocytogenes challenge mice model is widely accepted for studies involving cellular immune responses against bacterial infection. In the present study, we used a L. monocytogenes infection model to examine the protective effects of JWS 833 against pathogenic infection by pathogens. L.