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Desulfovibrio spp. is predominant member of sulphate‐reducing bacteria in human gut microbiota. Previous studies indicated that the isolation of Desulfovibrio strains from human faecal samples is very important to study the roles of human intestinal Desulfovibrio spp. in maintaining healthy states or causing diseases, as well as defining their biological characteristics. However, there are very few reports describing the isolation of Desulfovibrio spp. from human faecal samples. In this study, faecal samples were inoculated into various media containing different components. The enriched culture communities were identified using 16S rRNA gene high‐throughput sequencing analysis, enabling us to identify the specific components that enable the enrichment of Desulfovibrio. Using this information, we developed five specific media and identified an effective enrichment medium that produced the highest relative abundance of Desulfovibrio in communities cultured from four faecal samples (26·5, 73·5, 44·7 and 77·6% respectively). In addition, the major non‐Desulfovibrio genera were identified. Finally, three species of Desulfovibrio, D. desulfuricans, D. piger and D. legallii were isolated, representing the first time that has D. legallii been isolated from a human gastrointestinal source. Significance and Impact of the Study: ost of the human intestinal bacteria have not been cultured because of lack of appropriate culture method and appropriate media. Desulfovibrio spp. is associated with several clinical conditions like inflammatory bowel disease, but until now there are very few reports describing the isolation of Desulfovibrio spp. from human faecal samples. In this study, 16S rRNA gene high‐throughput sequencing analysis was applied to screen appropriate enrichment media and selective cultivation of Desulfovibrio. This sequencing‐based directed culture method described here can be used for the selective cultivation of gut bacteria of interest. [ABSTRACT FROM AUTHOR]

Lipopolysaccharide ( LPS) produced by Gram-negative bacteria induces tolerance and suppresses inflammatory responses in vivo; however, the mechanisms are poorly understood. In this study we show that LPS induces apoptosis of bone marrow-derived dendritic cells ( DCs) and modulates phenotypes of DCs. LPS treatment up-regulates expression of tolerance-associated molecules such as CD205 and galectin-1, but down-regulates expression of Gr-1 and B220 on CD11c+ DCs. Moreover, LPS treatment regulates the numbers of CD11c+ CD8+, CD11c+ CD11blow and CD11c+ CD11bhi DCs, which perform different immune functions in vivo. Our data also demonstrated that intravenous transfer of LPS-treated DCs blocks experimental autoimmune encephalomyelitis (EAE) development and down-regulates expression of retinoic acid-related orphan receptor gamma t (ROR-γt), interleukin ( IL)-17 A, IL-17 F, IL-21, IL-22 and interferon ( IFN)-γ in myelin oligodendrocyte glycoprotein (MOG)-primed CD4+ T cells in the peripheral environment. These results suggest that LPS-induced apoptotic DCs may lead to generation of tolerogenic DCs and suppress the activity of MOG-stimulated effector CD4+ T cells, thus inhibiting the development of EAE in vivo. Our results imply a potential mechanism of LPS-induced tolerance mediated by DCs and the possible use of LPS-induced apoptotic DCs to treat autoimmune diseases such as multiple sclerosis. [ABSTRACT FROM AUTHOR]

Nasal administration of nicotinic acetylcholine receptor (AChR) to Lewis rats prior to myasthenogenic immunization with AChR plus Freund's complete adjuvant (FCA) resulted in prevention or marked decrease of the severity of EAMG, suppression of AChR-specific B cell responses and of AChR-reactive T cell functions. To examine the involvement of immunoregulatory cytokines and the underlying mechanisms involved in tolerance induction, in situ hybridization with radiolabelled synthetic oligonucleotide probes was adapted to enumerate mononuclear cells (MNC) expressing mRNA for the proinflammatory cytokine IFN-γ, the B cell stimulating IL-4 and the immune response-down-regulating TGF-β. Popliteal and inguinal lymph nodes from EAMG rats contained elevated numbers of AChR-reactive IFN-γ, IL-4 and TGF-β mRNA-expressing cells compared with control rats receiving PBS nasally and injected with FCA only. Nasal tolerance to EAMG was accompanied by decreased numbers of AChR-reactive IFN-γ and IL-4 mRNA expressing cells, and strong up-regulation of TGF-β mRNA-positive cells in lymphoid organs compared with non-tolerized EAMG control rats. The relative affinity of anti-AChR antibodies was lower, but muscle AChR amounts were higher in nasally tolerized rats compared with nontolerized EAMG control rats. The results suggest that IFN-γ and IL-4 are central effector molecules in the development of EAMG, and that TGF-β plays an important rote in tolerance induction to EAMG. [ABSTRACT FROM AUTHOR]

We utilized a model of myelin basic protein (MBP) activation in vivo and MBP-stimulated cultures in vitro to study the influence of TGF-β1 on glial cell proliferation and ICAM-l/leucocyte function-associated antigen-1 (LFA-1) expression, and to observe the antagonistic effects of TGF-β1 and IFN-γ. TGF-β1 inhibited MBP-stimulated and MBP-activated glial cell proliferation, especially in MBP-stimulated separated microglia and astrocytes, and down-regulated the expression of ICAM-1 on MBP-stimulated glial cells and .separated microglia. ICAM-1 expression on MBP-activated glial cells was intensely suppressed, whereas its expression on MBP-stimulated astrocytes was not influenced. TGF-β1 had no effect on LFA-1 expression. In contrast, IFN-γ up-regulated ICAM-1 expression, but inhibited proliferative response on MBP-stimulated glial cells when cultured without TGF-Tbeta;1. Examination of TGF-β1 and IFN-γ interactions revealed that TGF-β1-mediated inhibition of proliferation and down-regulation of ICAM-1 on glial cells were prevented by IFN-γ. The suppressive effect was re-established with high doses of TGF-β1 in cultures, indicating that biological effects of TGF-β1 vary depending on nitric oxide (NO) production, its concentration in the microenvironment and regulation of the cytokine network. [ABSTRACT FROM AUTHOR]