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21.
Joanna Maria Radziwill-Bienkowska Doan Thanh Lam Le Pawel Szczesny Marie-Pierre Duviau Tamara Aleksandrzak-Piekarczyk Pascal Loubière Muriel Mercier-Bonin Jacek Karol Bardowski Magdalena Kowalczyk 《Applied microbiology and biotechnology》2016,100(22):9605-9617
Understanding the nature of mucus-microbe interactions will provide important information that can help to elucidate the mechanisms underlying probiotic adhesion. This study focused on the adhesive properties of the Lactococcus lactis subsp. cremoris IBB477 strain, previously shown to persist in the gastrointestinal tract of germ-free rats. The shear flow-induced detachment of L. lactis cells was investigated under laminar flow conditions. Such a dynamic approach demonstrated increased adhesion to bare and mucin-coated polystyrene for IBB477, compared to that observed for the MG1820 control strain. To identify potential genetic determinants giving adhesive properties to IBB477, the improved high-quality draft genome sequence comprising chromosome and five plasmids was obtained and analysed. The number of putative adhesion proteins was determined on the basis of surface/extracellular localisation and/or the presence of adhesion domains. To identify proteins essential for the IBB477 specific adhesion property, nine deletion mutants in chromosomal genes have been constructed and analysed using adhesion tests on bare polystyrene as well as mucin-, fibronectin- or collagen IV-coated polystyrene plates in comparison to the wild-type strain. These experiments demonstrated that gene AJ89_07570 encoding a protein containing DUF285, MucBP and four Big_3 domains is involved in adhesion to bare and mucin-coated polystyrene. To summarise, in the present work, we characterised the adhesion of IBB477 under laminar flow conditions; identified the putative adherence factors present in IBB477, which is the first L. lactis strain exhibiting adhesive and mucoadhesive properties to be sequenced and demonstrated that one of the proteins containing adhesion domains contributes to adhesion. 相似文献
22.
Marie-Pierre Piccinni Letizia Lombardelli Federica Logiodice Ornela Kullolli Paola Parronchi Sergio Romagnani 《Clinical and molecular allergy : CMA》2016,14(1):11
Autoimmune disorders are characterized by tissue damage, caused by self-reactivity of different effectors mechanisms of the immune system, namely antibodies and T cells. Their occurrence may be associated with genetic and/or environmental predisposition and to some extent, have implications for fertility and obstetrics. The relationship between autoimmunity and reproduction is bidirectional. This review only addresses the impact of pregnancy on autoimmune diseases and not the influence of autoimmunity on pregnancy development. Th17/Th1-type cells are aggressive and pathogenic in many autoimmune disorders and inflammatory diseases. The immunology of pregnancy underlies the role of Th2-type cytokines to maintain the tolerance of the mother towards the fetal semi-allograft. Non-specific factors, including hormonal changes, favor a switch to Th2-type cytokine profile. In pregnancy Th2, Th17/Th2 and Treg cells accumulate in the decidua but may also be present in the mother’s circulation and can regulate autoimmune responses influencing the progression of autoimmune diseases. 相似文献
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Sofía Ruiz-Cruz Andrea Erazo Garzon Philip Kelleher Francesca Bottacini Solvej Østergaard Breum Horst Neve Knut J. Heller Finn K. Vogensen Simon Palussière Pascal Courtin Marie-Pierre Chapot-Chartier Evgeny Vinogradov Irina Sadovskaya Jennifer Mahony Douwe van Sinderen 《Microbial biotechnology》2022,15(12):2875-2889
The first step in phage infection is the recognition of, and adsorption to, a receptor located on the host cell surface. This reversible host adsorption step is commonly followed by an irreversible event, which involves phage DNA delivery or release into the bacterial cytoplasm. The molecular components that trigger this latter event are unknown for most phages of Gram-positive bacteria. In the current study, we present a comparative genome analysis of three mutants of Lactococcus cremoris 3107, which are resistant to the P335 group phage TP901-1 due to mutations that affect TP901-1 DNA release. Through genetic complementation and phage infection assays, a predicted lactococcal three-component glycosylation system (TGS) was shown to be required for TP901-1 infection. Major cell wall saccharidic components were analysed, but no differences were found. However, heterologous gene expression experiments indicate that this TGS is involved in the glucosylation of a cell envelope-associated component that triggers TP901-1 DNA release. To date, a saccharide modification has not been implicated in the DNA delivery process of a Gram-positive infecting phage. 相似文献
25.
Malet H Egloff MP Selisko B Butcher RE Wright PJ Roberts M Gruez A Sulzenbacher G Vonrhein C Bricogne G Mackenzie JM Khromykh AA Davidson AD Canard B 《The Journal of biological chemistry》2007,282(14):10678-10689
Viruses of the family Flaviviridae are important human and animal pathogens. Among them, the Flaviviruses dengue (DENV) and West Nile (WNV) cause regular outbreaks with fatal outcomes. The RNA-dependent RNA polymerase (RdRp) activity of the non-structural protein 5 (NS5) is a key activity for viral RNA replication. In this study, crystal structures of enzymatically active and inactive WNV RdRp domains were determined at 3.0- and 2.35-A resolution, respectively. The determined structures were shown to be mostly similar to the RdRps of the Flaviviridae members hepatitis C and bovine viral diarrhea virus, although with unique elements characteristic for the WNV RdRp. Using a reverse genetic system, residues involved in putative interactions between the RNA-cap methyltransferase (MTase) and the RdRp domain of Flavivirus NS5 were identified. This allowed us to propose a model for the structure of the full-length WNV NS5 by in silico docking of the WNV MTase domain (modeled from our previously determined structure of the DENV MTase domain) onto the RdRp domain. The Flavivirus RdRp domain structure determined here should facilitate both the design of anti-Flavivirus drugs and structure-function studies of the Flavivirus replication complex in which the multifunctional NS5 protein plays a central role. 相似文献
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pS2/TFF1 overexpression in breast carcinomas correlates with response to hormonotherapy. We evaluated the clinical relevance of urinary pS2/TFF1 in breast cancer patients. In healthy controls (100 cases), it represents an individual and relatively stable parameter. Although 24 out 83 pre-operative breast cancer patients showed elevated levels, both the sensitivity and specificity of the test were too low for breast cancer screening. However, neoadjuvant hormonotherapy decreased pS2/TFF1 levels in nine out of 20 patients. Furthermore, among 22 patients receiving long-term adjuvant hormonotherapy, four exhibited elevated levels, two of them at the time of relapse. Thus, urinary pS2/TFF1 quantification might be suitable as an in vivo diagnosis for tumor hormonodependency, and disease follow-up during hormonotherapy. 相似文献
28.
An in vitro dual model of mycobacterial granulomas to investigate the molecular interactions between mycobacteria and human host cells 总被引:1,自引:0,他引:1
Puissegur MP Botanch C Duteyrat JL Delsol G Caratero C Altare F 《Cellular microbiology》2004,6(5):423-433
In the majority of individuals infected with Mycobacterium tuberculosis, the bacilli cause a long-term asymptomatic infection called latent tuberculosis, a state during which the bacilli reside within granulomas. Latently infected individuals have around 10% risk of progression to clinical disease at a later stage. Determining the state of the mycobacteria and the host cells during this latent phase, i.e. within the granulomas, would greatly improve our understanding of the physiopathology of tuberculosis, and thus enable the development of new therapeutic means to treat the one-third of the world's population who are latently infected. We have developed an in vitro model of human mycobacterial granulomas, enabling the cellular and molecular analysis of the very first steps in the host granulomatous response to either mycobacterial compounds or live mycobacterial species. In vitro mycobacterial granulomas mimic natural granulomas very well, with the progressive recruitment of macrophages around live bacilli or mycobacterial antigen-coated beads, their differentiation into multinucleated giant cells and epithelioid cells, and the final recruitment of a ring of activated lymphocytes. Besides morphological similarities, in vitro granulomas also functionally resemble natural ones, with the development of intense cellular co-operation and intracellular mycobactericidal activities. 相似文献
29.
Dietary phytosterols have been shown to reduce plasma cholesterol concentrations when consumed in different food matrices, but their effectiveness in nonfat or low-fat beverages has not been established. The objective of this study was to examine whether phytosterols alter plasma lipid levels when incorporated into nonfat or low-fat beverages. Fifteen moderately hypercholesterolemic men and women consumed three precisely controlled diets for periods of 21 days each in random order. Diets contained either a nonfat placebo beverage (NF), a beverage that is nonfat with added phytosterols (NFPS), or a beverage that is low in fat with added phytosterols (LFPS). Total cholesterol concentrations were not different between groups at endpoint, decreasing (P < 0.05) equally by 8.5%, 11.6%, and 10.1% with NF, NFPS, and LFPS consumption, respectively. There was no effect of dietary treatment on LDL cholesterol concentrations, which decreased over time (P < 0.05) by 5%, 10.4%, and 8.5% with NF, NFPS, and LFPS, respectively. HDL cholesterol and triacylglycerol concentrations were unaffected by the diets. Provision of phytosterols as part of nonfat and low-fat beverages did not exert any greater hypocholesterolemic effect than a nonfat placebo beverage. These results show that intake of phytosterols in a low-fat beverage format is not efficacious for lipid level modification. 相似文献
30.
Ducros V Demuth K Sauvant MP Quillard M Caussé E Candito M Read MH Drai J Garcia I Gerhardt MF;SFBC Working group on homocysteine. French Society for Clinical Biology 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2002,781(1-2):207-226
It is now widely accepted that increased total plasma homocysteine (tHcy) is a risk factor for cardiovascular disease. Hyperhomocysteinemia can be caused by impaired enzyme function as a result of genetic mutation or vitamin B (B(2), B(6), B(9), B(12)) deficiency. A lot of methods are now available for tHcy determination. High-pressure liquid chromatography (HPLC) with fluorescence detection are at present the most widely used methods but immunoassays, easier to use, begin to supplant in-house laboratory methods. In order to help with the choice of a main relevant homocysteine analytical method, the characteristics, performances and limits of the main current methods are reviewed. One major drawback among all these available methods is the transferability which is not clearly established to date. The impact of both inter-method and inter-laboratory variations on the interpretation of the tHcy results are discussed. 相似文献