![]() Vi expression can thus facilitate a stealth mode of pathogenesis promoting systemic spread and limiting the clinical signatures of gastroenteritis. Such signatures include reduced levels of growth related oncogene α (GROα) and IL-17, and reduced fluid influx and neutrophil recruitment in the Salmonella bovine ileal loop model. For example, Vi expression on Salmonella can reduce the inflammatory response in intestinal epithelial cells and throughout systemic infection. Typhi) which is associated with virulence. Typhi isolates express a polysaccharide capsule (Vi CPS) known as Vi (Vi + S. Typhi with an estimated 12 to 22 million cases of typhoid fever per annum resulting in between 129,000 and 217,000 deaths. Humans are the only known natural hosts of S. Typhi) is the causative agent of the systemic disease typhoid fever. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors. There are no patents, products in development or marketed products to declare. MacLennan was an employee of the Novartis Vaccines Institute for Global Health in the past. Francesca Micoli is an employee of the Sclavo Behring Vaccines Institute for Global Health. MacLennan is the recipient of a clinical research fellowship from GlaxoSmithKline. The specific role of this author is articulated in the ‘author contributions’ section.Ĭompeting interests: The authors have the following interests. Sclavo Behring Vaccines Institute for Global Health, a GlaxoSmithKline Company, provided support in the form of salary for author FM, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. CAM received a clinical research fellowship from GlaxoSmithKline. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedĭata Availability: All relevant data are within the paper and its Supporting Information files.įunding: PJH was supported by an MRC PhD studentship. Received: SeptemAccepted: DecemPublished: January 7, 2016Ĭopyright: © 2016 Hart et al. PLoS ONE 11(1):Įditor: Mikael Skurnik, University of Helsinki, FINLAND (2016) Differential Killing of Salmonella enterica Serovar Typhi by Antibodies Targeting Vi and Lipopolysaccharide O:9 Antigen. Our findings support a protective role for Vi capsule in preventing complement and phagocyte killing of Salmonella that can be overcome by specific anti-Vi antibodies, but only to a limited extent by anti-O:9 antibodies.Ĭitation: Hart PJ, O’Shaughnessy CM, Siggins MK, Bobat S, Kingsley RA, Goulding DA, et al. Human serum depleted of antibodies to antigens other than Vi retains the ability to kill Vi-expressing bacteria. However, purified human anti-Vi antibodies in the presence of complement are able to kill Vi-expressing Salmonella, while killing by anti-O:9 antibodies is inversely related to Vi expression. The Vi capsule is associated with reduced C3 and C5b-9 deposition, and decreased overall antibody binding to S. ![]() Vi expression confers increased resistance to both complement- and phagocyte-mediated modalities of antibody-dependent killing in human blood. Typhi is inherently more sensitive to serum and blood than S. Using isogenic Vi-expressing and non-Vi-expressing derivatives of S. ![]() Here we investigate the role of Vi capsule and antibodies against Vi and O:9 in antibody-dependent complement- and phagocyte-mediated killing of Salmonella. Vaccines based on Vi polysaccharide have efficacy against typhoid fever, indicating that antibodies against Vi confer protection. Enteritidis express the lipopolysaccharide O:9 antigen, yet there is little evidence of cross-protection from anti-O:9 antibodies. Salmonella enterica serovar Typhi expresses a capsule of Vi polysaccharide, while most Salmonella serovars, including S.
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