乳酸菌黏附小鼠派伊尔结及影响因子的研究

目的研究乳酸菌结合小鼠派伊尔结（PP）的性质,确定乳酸菌黏附小鼠PP的影响因子。方法测定10株荧光标记的乳酸菌对PP组织切片黏附性,分析细菌表面疏水性和酵母、红细胞凝集性与黏附性的关系。结果凝集酵母、红细胞能力强的乳酸菌,PP黏附性强。除嗜酸乳杆菌（L.acidophilm）外,其他9株乳酸菌的表面疏水性与凝集酵母、红细胞的能力呈显著的负相关性（r=-0．60和r=-0．53,P〈0．05）。L.acidophilm黏附PP的能力最强。L．acidophilm黏附PP能力和红细胞凝集性均可被D（＋）-甘露糖、D（＋）-半乳糖抑制。结论乳酸菌黏附PP的能力受疏水性和表面特异性凝集素的影响。L.acidophilm表面D（＋）-甘露糖、D（＋）-半乳糖特异性凝集素可能参与黏附PP的过程。     

Intestinal immunostimulatory activity of neutral polysaccharide isolated from traditionally fermented Korean brown rice vinegar

In this study, diverse intestinal immunostimulatory activities were demonstrated for polysaccharides (KBV-CP) isolated from Korean brown rice vinegar. Monosaccharide composition analysis indicated that KBV-CP was composed mainly of neutral sugar units, primarily glucose and mannose. In vitro, KBV-CP significantly augmented the productions of immunoglobulin A (IgA) and IgA-related cytokines such as interleukin-6 (IL-6) and transforming growth factor-β (TGF-β) in a dose-dependent manner. Furthermore, results of an in vitro co-culture system of intestinal Caco-2 cells and RAW 264.7 macrophage cells suggested that KBV-CP is not only cytotoxic to Caco-2 cells but also capable of being transported across the small intestinal barrier. Oral administration of KBV-CP every other day for 20 days induced the IgA production by Peyer’s patch cells as well as in intestinal fluid and fecal extract. In addition, the production of IgA-related cytokines such as TGF-β and IL-6, and granulocyte macrophage colony-stimulating factor was triggered.     

B Cell Diversification Is Uncoupled from SAP-Mediated Selection Forces in Chronic Germinal Centers within Peyer’s Patches

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Early feed restriction of lambs modifies ileal epimural microbiota and affects immunity parameters during the fattening period

Bacteria firmly attached to the gastrointestinal epithelium during the pre-weaning phase may show a significant impact on nutrient processing, immunity parameters, health and feed efficiency of lambs during post-weaning phases. Thus, the aim of this study was to describe the differences in the ileal epimural microbiota (e.g. total bacteria, Prevotella spp., Bifidobacterium spp. and Lactobacillus spp.) of fattening lambs promoted by early feed restriction during the suckling phase trying to elucidate some of the underlying mechanisms behind changes in feed efficiency during the fattening period. A total of 24 Merino lambs (average BW 4.81±0.256 kg) were used, 12 of them (ad libitum, ADL) kept permanently in individual pens with their mothers, whereas the other 12 lambs were separated from their dams for 9 h each day to be exposed to milk restriction (RES). After weaning (BW=15 kg) all the animals were penned individually, offered the same complete pelleted diet (35 g/kg BW per day) and slaughtered at a BW of 27 kg. During the fattening period, reduced gain : feed ratio (0.320 v. 0.261, P<0.001) was observed for the RES group. Moreover, increments of Prevotella spp. were detected in the ileal epimural microbiota of RES lambs (P<0.05). There were also higher numbers of infiltrated lymphocytes (T and B cells) in the ileal lamina propria (P<0.05), a higher M-cell labelling intensity in ileal Peyer’s patches domes (P<0.05) and a trend towards a thickening of the submucosa layer when compared with the ADL group (P=0.057). Some other immunological parameters, such as an increased immunoglobulin A (IgA) production (pg IgA/µg total protein) and increments in CD45+ cells were also observed in the ileum of RES group (P<0.05), whereas transforming growth factor β and toll-like receptor gene expression was reduced (P<0.05). In conclusion, early feed restriction during the suckling phase promoted changes in ileal epimural microbiota and several immunity parameters that could be related to differences in feed efficiency traits during the fattening period of Merino lambs.     

N-Acylation of N-Desulfated Heparin

We found that the epigallocatechin gallate (EGCG)/epigallocatechin (EGC) ratio in a green tea (Camellia sinensis L.) extract was affected by the extraction temperature. The EGCG/EGC ratio in the 4 °C extract was around 1:3-4, whereas in the 100 °C extract, it was around 1:0.7. Oral administration of the mixture with a high EGC ratio (1:2-3 = EGCG/EGC) resulted in greater IgA production by murine Peyer’s patch cells.     

旋毛虫感染与肠黏膜免疫应答作用的研究进展

旋毛虫病是一种常见的人兽共患寄生虫病,也是一种重要的食源性寄生虫病,严重危害着人类的健康。肠黏膜是肠道寄生虫（包括旋毛虫等）进入宿主的重要门户,即机体非特异性抗感染的第一道防线,也是宿主抵御肠道寄生虫入侵的重要固有屏障,后者发挥着固有性免疫和适应性免疫功能的作用。宿主的肠黏膜免疫应答反应决定旋毛虫与宿主相互作用和适应关系。本研究就目前国内外学者研究旋毛虫感染与宿主免疫的现状,分别从肠道黏膜组织学结构、免疫细胞、细胞因子和小肠上皮细胞4个方面,综述一下肠黏膜对旋毛虫感染的免疫应答作用,目的在于揭示宿主肠黏膜对旋毛虫感染的免疫应答机制。     

Lipid Composition and Localization of 10-Methyl Branched-chain Fatty Acids in Corynebacterium simplex Grown on n-Alkanes

1. Corynebacterium simplex ATCC 6946 grown on a n-alkane mixture (C₁₄-C₁₆) contained 13% of total lipids, which composed of approximately equal quantities of neutral lipids and compound lipids. Phospholipids, corresponding to about 60% of compound lipids, comprised phosphatidylinositol mannoside and cardiolipin as the major components, and phosphatidylglycerol and phosphatidylethanolamine as the minor components.

2. When this bacterium was cultivated on n-octadecane in the presence of cobaltous ion, a large amount of tuberculostearic acid (10-methylstearic acid) was synthesized, which was exclusively localized in phosphatidylinositol mannoside and was not detected in neutral lipids.     

Effect of Dietary Cyclic Nigerosylnigerose on Intestinal Immune Functions in Mice

We examined the dietary effects of cyclic nigerosylnigerose (CNN), a dietary indigestible oligosaccharide with four D-glucopyranosyl residues linked by alternating α-(1→3)- and α-(1→6) glucosidic linkages, on the intestinal immune function of mice, and the effects were compared with those of α-(1→3)-linked oligosaccharide (nigerooligosaccharides, NOS) or α-(1→6)-linked oligosaccharide (isomaltooligosaccharides, IMO). BALB/c mice were fed with 1–5% CNN, 5% IMO, or 12.5% NOS for 4 weeks, and the intestinal mucosal immune responses were determined. In the 1–5% CNN fed groups, the amounts of IgA in feces increased significantly. In addition, IgA, transforming growth factor-β1 (TGF-β1), and interleukin-6 (IL-6) secretion by Peyer’s patch (PP) cells were enhanced in CNN fed mice. In the 5% CNN group, pH in the cecum decreased, and the amounts of lactic acid and butyric acid increased. These findings were not observed in the NOS- or IMO-fed group of mice. They suggest that CNN supplementation changes the intestinal environment of microflora and indirectly enhances the immune function in the gut.     

3′-Phosphorylation of Aminoglycoside Antibiotics by Some Strains of Nocardia

Some strains of Nocardia were found to contain weak activities to phosphorylate aminoglycoside antibiotics in cell-free extracts. Properties of butirosin A resistant mutants derived from N. asteroides IFO 3423 were examined. An increase in their resistance to aminoglycoside antibiotics and their aminoglycoside 3′-phosphotransferase [APh(3′)] contents were shown to be well closely comparable. The findings indicate that APh(3′) of N. asteroides can be a biochemical mechanism in resistance to aminoglycoside antibiotics.

The mutant, BUR-38 with the largest increase in APh(3′) was examined for preparation of 3′-phosphate derivatives of aminoglycoside antibiotics. The derivatives were known to be useful intermediates in the chemical transformation of aminoglycoside antibiotics to more potent 3′-deoxy forms against resistant clinically-isolated bacteria. A nonionic detergent, sodium dodecyl sulfate was found to be very effective on 3′-phosphorylation of xylostasin and butirosin A by intact cells.