[3+2] Annulation of Donor–Acceptor Cyclopropanes with Vinyl Azides

A Sc(OTf)3-catalyzed reaction of vinyl azides with donor–acceptor cyclopropanes affords highly functionalized azidocyclopentanes in a diastereoselective fashion. The resulting azidocyclopentanes could be transformed into various cyclic scaffolds.MOE (Min. of Education, S’pore)Accepted versio

β-(1,3)-Glucan derived from induces inflammatory cytokines from macrophages and lamina propria mononuclear cells derived from patients with Crohn's disease

Background/AimsRecent research has highlighted the importance of interactions between commensal fungi and intestinal inflammation. However, there are few studies investigating whether commensal fungi contribute to inflammation in patients with Crohn's disease (CD). The aim of this study is to investigate reveal interactions between commensal fungi and host immune cells in CD.MethodsCD14-positive monocytes were isolated from peripheral blood mononuclear cells from healthy human volunteers and then differentiated in the presence of macrophage colony-stimulating factor (M-CSF) (referred to as M-macrophages, M-Mϕs) or M-CSF and interferon-γ (IFN-γ) (referred to as M-gamma macrophages, Mγ-Mϕs). Cytokine production by these in vitro differentiated macrophages in response to β-(1,3)-glucan was analyzed by flow cytometry. Expression of Dectin-1 was examined using flow cytometry, western blotting, and quantitative reverse transcription-polymerase chain reaction. Cytokine production by in vitro differentiated macrophages in response to β-(1,3)-glucan was measured in the presence of an anti-Dectin-1 receptor antagonist, anti-Syr, or an anti-Fas-1 antibody. Cytokine production by lamina propria mononuclear cells (LPMCs) derived from CD patients in response to β-(1,3)-glucan was also analyzed.ResultsMγ-Mϕs produced a large amount of tumor necrosis factor-α (TNF-α) and interleukin-6 in response to β-(1,3)-glucan. Dectin-1 expression was significantly higher in Mγ-Mϕs than in M-Mϕs. The increase in TNF-α production by Mγ-Mϕs stimulated with glucan was reversed by blocking Dectin-1, Syr or Fas-1. LPMCs derived from CD patients stimulated with β-(1,3)-glucan produced significantly higher amount of TNF-α than LPMCs derived from UC patients.ConclusionsThese results suggest that commensal fungal microbiota may contribute to the pathogenesis of CD by inducing macrophages-derived pro-inflammatory cytokines

Commensal Lactobacillus Controls Immune Tolerance during Acute Liver Injury in Mice

Summary: Gut-derived microbial antigens trigger the innate immune system during acute liver injury. During recovery, regulatory immunity plays a role in suppressing inflammation; however, the precise mechanism underlying this process remains obscure. Here, we find that recruitment of immune-regulatory classical dendritic cells (cDCs) is crucial for liver tolerance in concanavalin A-induced acute liver injury. Acute liver injury resulted in enrichment of commensal Lactobacillus in the gut. Notably, Lactobacillus activated IL-22 production by gut innate lymphoid cells and raised systemic IL-22 levels. Gut-derived IL-22 enhanced mucosal barrier function and promoted the recruitment of regulatory cDCs to the liver. These cDCs produced IL-10 and TGF-β through TLR9 activation, preventing further liver inflammation. Collectively, our results indicate that beneficial gut microbes influence tolerogenic immune responses in the liver. Therefore, modulation of the gut microbiota might be a potential option to regulate liver tolerance. : Nakamoto et.al. find that Lactobacillus accumulates in the gut and activates IL-22 production by innate lymphoid cells during acute liver injury. Gut-derived IL-22 contributes to liver tolerance via induction of regulatory DCs. Keywords: immune tolerance, dendritic cell, innate lymphoid cell, acute liver injury, interleukin-10, interleukin-22, microbiota, dysbiosi