\u3cem\u3eMycobacterium avium\u3c/em\u3e subsp. \u3cem\u3eparatuberculosis\u3c/em\u3e lipophilic antigen causes Crohn’s disease-type necrotizing colitis in Mice

Background: A 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced murine colitis model was developed to investigate the pathogenesis and to evaluate a method of treating human Crohn’s disease. This experimental model rapidly induces colitis similar to human Crohn’s disease lesion in a reproducible manner. However, natural exposure of the human digestive tract to TNBS is unrealistic. A novel animal model based on realistic data is eagerly anticipated in future research on pathogenesis of CD. Method: We evaluated the potency of Map antigen molecules in an effort to develop a novel colitis model using a more realistic source than TNBS. We prepared the Map antigen by ethanol extraction and developed a mouse model in a manner similar to that of the well-known TNBS-induced colitis in mice. In the experiment, seven days after subcutaneous (SC) injection of the antigen into normal C57BL/6 mice, the same antigen in 50% ethanol was injected into the colon by the transanal route with a fine cannula. Results: On the fifth day after the transanal injection, histopathological examination revealed full-thickness necrotizing colitis with erosion and ulcers; severe infiltration with neutrophils, lymphocytes, macrophages, and perforation. However, no change was detected with each single Map-antigen injection. Conclusion: The present results provide a novel animal model for research on CD and may be the key to clarifying the relationship between CD and Map. This is the first evidence that mycobacterium antigen induces necrotizing colitis

p62 Plays a Specific Role in Interferon-γ-Induced Presentation of a Toxoplasma Vacuolar Antigen

Also known as Sqstm1, p62 is a selective autophagy adaptor with a ubiquitin-binding domain. However, the role of p62 in the host defense against Toxoplasma gondii infection is unclear. Here, we show that interferon γ (IFN-γ) stimulates ubiquitin and p62 recruitment to T. gondii parasitophorous vacuoles (PVs). Some essential autophagy-related proteins, but not all, are required for this recruitment. Regardless of normal IFN-γ-induced T. gondii clearance activity and ubiquitination, p62 deficiency in antigen-presenting cells (APCs) and mice diminishes the robust IFN-γ-primed activation of CD8+ T cells that recognize the T. gondii-derived antigen secreted into PVs. Because the expression of Atg3 and Irgm1/m3 in APCs is essential for PV disruption, ubiquitin and p62 recruitment, and vacuolar-antigen-specific CD8+ T cell activation, IFN-γ-mediated ubiquitination and the subsequent recruitment of p62 to T. gondii are specifically required for the acquired immune response after PV disruption by IFN-γ-inducible GTPases

Vegetable juice preload ameliorates postprandial blood glucose concentration in healthy women : A randomized cross-over trial

Background and Objectives: The aim of this study was to evaluate the acute effect of drinking vegetable juice 20 min before carbohydrate on postprandial blood glucose concentrations in young healthy women. Method: In this randomized controlled cross-over study, 24 women (age 21.3 ±0.6 years, HbA1c 5.4 ±0.2 %, mean ± SD) consumed either 200 g of vegetable juice, vegetable (150 g of tomato and 40 g of broccoli), or water at 20 min before consuming 200 g of boiled white rice for 3 separate days. The blood glucose concentrations were measured by self-monitoring blood glucose pre- and post-breakfast at -20, 0, 15, 30, 45, 60, 120, and 180 min. The glycemic parameters were compared among 3 days. Results: The incremental glucose peak at 45 min (vegetable juice 48.3 ± 4.1, vegetable 47.4 ± 3.3 vs. water 66.8 ± 4.3 mg/dl, respectively, both p < 0.01, mean ± SEM) and large amplitude of glycemic excursion (LAGE; vegetable juice 57.1 ± 3.1, vegetable 58.3 ± 3.6 vs. water 78.3 ± 4.3 mg/dl, respectively, both p < 0.05) in consuming vegetable juice and vegetable at 20 min before carbohydrate intake were all significantly lower than those of water. There was no significant difference between glycemic parameters of vegetable juice and vegetable. Conclusions: Drinking vegetable juice 20 min before carbohydrate ameliorates the postprandial blood glucose concentrations as well as vegetable preload, despite total amounts of energy and carbohydrate of vegetable juice or vegetable are higher than those of water

Essential role of IRAK-4 protein and its kinase activity in Toll-like receptor–mediated immune responses but not in TCR signaling

Interleukin-1 receptor–associated kinase 4 (IRAK-4) was reported to be essential for the Toll-like receptor (TLR)– and T cell receptor (TCR)–mediated signaling leading to the activation of nuclear factor κB (NF-κB). However, the importance of kinase activity of IRAK family members is unclear. In this study, we investigated the functional role of IRAK-4 activity in vivo by generating mice carrying a knockin mutation (KK213AA) that abrogates its kinase activity. IRAK-4KN/KN mice were highly resistant to TLR-induced shock response. The cytokine production in response to TLR ligands was severely impaired in IRAK-4KN/KN as well as IRAK-4−/− macrophages. The IRAK-4 activity was essential for the activation of signaling pathways leading to mitogen-activated protein kinases. TLR-induced IRAK-4/IRAK-1–dependent and –independent pathways were involved in early induction of NF-κB–regulated genes in response to TLR ligands such as tumor necrosis factor α and IκBζ. In contrast to a previous paper (Suzuki, N., S. Suzuki, D.G. Millar, M. Unno, H. Hara, T. Calzascia, S. Yamasaki, T. Yokosuka, N.J. Chen, A.R. Elford, et al. 2006. Science. 311:1927–1932), the TCR signaling was not impaired in IRAK-4−/− and IRAK-4KN/KN mice. Thus, the kinase activity of IRAK-4 is essential for the regulation of TLR-mediated innate immune responses

ラットにおけるα_2-macroglobulin生成に関する研究

The cahge of serum levesl of α_2-macrogolbulin (α2M) after administration of fraction corresponded to interleukin (IL)-6 or cytokine-induced neutrophil chemoattractant-1 (CINC-1) in rats were investigated. The serum levels of α_2M increased franction of corresponded of IL-6 or CINC-1 and peak levels 260.7 μg/ml at 48 h and 357.5 μ/ml at 24 h after administration, respectively. These results suggested that IL- 6 and CINC-1 were presumed to be contributed production of α2M

The Roles of Two IκB Kinase-related Kinases in Lipopolysaccharide and Double Stranded RNA Signaling and Viral Infection

Viral infection and stimulation with lipopolysaccharide (LPS) or double stranded RNA (dsRNA) induce phosphorylation of interferon (IFN) regulatory factor (IRF)-3 and its translocation to the nucleus, thereby leading to the IFN-β gene induction. Recently, two IκB kinase (IKK)–related kinases, inducible IκB kinase (IKK-i) and TANK-binding kinase 1 (TBK1), were suggested to act as IRF-3 kinases and be involved in IFN-β production in Toll-like receptor (TLR) signaling and viral infection. In this work, we investigated the physiological roles of these kinases by gene targeting. TBK1-deficient embryonic fibroblasts (EFs) showed dramatic decrease in induction of IFN-β and IFN-inducible genes in response to LPS or dsRNA as well as after viral infection. However, dsRNA-induced expression of these genes was residually detected in TBK1-deficient cells and intact in IKK-i–deficient cells, but completely abolished in IKK-i/TBK1 doubly deficient cells. IRF-3 activation, in response not only to dsRNA but also to viral infection, was impaired in TBK1-deficient cells. Together, these results demonstrate that TBK1 as well as, albeit to a lesser extent, IKK-i play a crucial role in the induction of IFN-β and IFN-inducible genes in both TLR-stimulated and virus-infected EFs

Toll-like receptor 9 mediates innate immune activation by the malaria pigment hemozoin

Malaria parasites within red blood cells digest host hemoglobin into a hydrophobic heme polymer, known as hemozoin (HZ), which is subsequently released into the blood stream and then captured by and concentrated in the reticulo-endothelial system. Accumulating evidence suggests that HZ is immunologically active, but the molecular mechanism(s) through which HZ modulates the innate immune system has not been elucidated. This work demonstrates that HZ purified from Plasmodium falciparum is a novel non-DNA ligand for Toll-like receptor (TLR)9. HZ activated innate immune responses in vivo and in vitro, resulting in the production of cytokines, chemokines, and up-regulation of costimulatory molecules. Such responses were severely impaired in TLR9−/− and myeloid differentiation factor 88 (MyD88)−/−, but not in TLR2, TLR4, TLR7, or Toll/interleukin 1 receptor domain–containing adaptor-inducing interferon β−/− mice. Synthetic HZ, which is free of the other contaminants, also activated innate immune responses in vivo in a TLR9-dependent manner. Chloroquine (CQ), an antimalarial drug, abrogated HZ-induced cytokine production. These data suggest that TLR9-mediated, MyD88-dependent, and CQ-sensitive innate immune activation by HZ may play an important role in malaria parasite–host interactions

Essential role of IPS-1 in innate immune responses against RNA viruses

IFN-β promoter stimulator (IPS)-1 was recently identified as an adapter for retinoic acid–inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (Mda5), which recognize distinct RNA viruses. Here we show the critical role of IPS-1 in antiviral responses in vivo. IPS-1–deficient mice showed severe defects in both RIG-I– and Mda5-mediated induction of type I interferon and inflammatory cytokines and were susceptible to RNA virus infection. RNA virus–induced interferon regulatory factor-3 and nuclear factor κB activation was also impaired in IPS-1–deficient cells. IPS-1, however, was not essential for the responses to either DNA virus or double-stranded B-DNA. Thus, IPS-1 is the sole adapter in both RIG-I and Mda5 signaling that mediates effective responses against a variety of RNA viruses

Bovine immune colostral antibody against verotoxin 2 derived from Escherichia coli O157:H7-resistance to proteases and effects on verotoxin 2 in small intestine of beagle dogs

Resistance to intestinal proteases and efficacy against verotoxin (VT) 2 of a colostral antibody administered orally via catheter were investigated in beagle dogs. Bovine colostral antibody remained in the small intestine for 2 hours, whereas little serum antibody remained at 1.5 hours after administration. The bovine colostral antibody was not inactivated by proteases in the small intestine. Furthermore, the antibody activity of S-IgA did not change until 2 hours after administration; however, the activity of IgG and IgM antibodies decreased by two-thirds and two-fifths at 2 hours after administration, respectively. Seven beagle dogs inoculated with Escherichia coli (E. coli) O157:H7 producing VT2 were administered bovine colostral antibody or bovine colostral whey without antibody. With administration of bovine colostral whey without antibody, the amount of VT2 in feces decreased gradually after administration and increased again at 5 days after inoculation, while bovine colostral antibody significantly reduced the amount of VT2 in feces the day after administration. In addition, 9 beagle dogs were administered bovine colostral antibody, bovine plasma antibody or saline. The amount of VT2 in feces also significantly reduced rapidly after administration of bovine colostral antibody than administration of bovine plasma antibody or saline