{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T05:10:58Z","timestamp":1772169058384,"version":"3.50.1"},"reference-count":35,"publisher":"F1000 Research Ltd","license":[{"start":{"date-parts":[[2017,10,26]],"date-time":"2017-10-26T00:00:00Z","timestamp":1508976000000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000274","name":"British Heart Foundation","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000274","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100004440","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["098516"],"award-info":[{"award-number":["098516"]}],"id":[{"id":"10.13039\/100004440","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100004440","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["110086"],"award-info":[{"award-number":["110086"]}],"id":[{"id":"10.13039\/100004440","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["wellcomeopenresearch.org"],"crossmark-restriction":false},"short-container-title":["Wellcome Open Res"],"abstract":"\n Background:<\/ns4:bold>\n Pseudomonas species are adapted to evade innate immune responses and can persist at sites of relative tissue hypoxia, including the mucus-plugged airways of patients with cystic fibrosis and bronchiectasis.\u00a0 The ability of these bacteria to directly sense and respond to changes in local oxygen availability is in part consequent upon expression of the 2-oxoglutarate oxygenase,\n Pseudomonas<\/ns4:italic>\n prolyl hydroxylase (PPHD), which acts on elongation factor Tu (EF-Tu), and is homologous with the human hypoxia inducible factor (HIF) prolyl hydroxylases. We report that PPHD expression regulates the neutrophil response to acute pseudomonal infection.\n <\/ns4:p>\n \n Methods:<\/ns4:bold>\n In vitro<\/ns4:italic>\n co-culture experiments were performed with human neutrophils and PPHD-deficient and wild-type bacteria and supernatants, with viable neutrophil counts determined by flow cytometry.\n In vivo<\/ns4:italic>\n consequences of infection with PPHD deficient\n P. aeruginosa<\/ns4:italic>\n were determined in an acute pneumonia mouse model following intra-tracheal challenge.\n <\/ns4:p>\n \n Results:<\/ns4:bold>\n Supernatants of PPHD-deficient bacterial cultures contained higher concentrations of the phenazine exotoxin pyocyanin and induced greater acceleration of neutrophil apoptosis than wild-type PAO1 supernatants\n in vitro.\u00a0 In vivo<\/ns4:italic>\n infection with PPHD mutants compared to wild-type PAO1 controls resulted in increased levels of neutrophil apoptosis and impaired control of infection, with higher numbers of\n P. aeruginosa<\/ns4:italic>\n recovered from the lungs of mice infected with the PPHD-deficient strain.\u00a0 This resulted in an overall increase in mortality in mice infected with the PPHD-deficient strain.\n <\/ns4:p>\n \n Conclusions:<\/ns4:bold>\n Our data show that\n Pseudomonas<\/ns4:italic>\n expression of its prolyl hydroxylase influences the outcome of host-pathogen interactions\n in vitro<\/ns4:italic>\n and\n in vivo<\/ns4:italic>\n , demonstrating the importance of considering how both host and pathogen adaptations to hypoxia together define outcomes of infection. Given that inhibitors for the HIF prolyl hydroxylases are in late stage trials for the treatment of anaemia and that the active sites of PPHD and human HIF prolyl hydroxylases are closely related, the results are of current clinical interest.\n <\/ns4:p>","DOI":"10.12688\/wellcomeopenres.12871.1","type":"journal-article","created":{"date-parts":[[2017,10,26]],"date-time":"2017-10-26T08:50:02Z","timestamp":1509007802000},"page":"104","update-policy":"https:\/\/doi.org\/10.12688\/wellcomeopenres.crossmark-policy","source":"Crossref","is-referenced-by-count":9,"title":["Pseudomonas expression of an oxygen sensing prolyl hydroxylase homologue regulates neutrophil host responses in vitro and in vivo"],"prefix":"10.12688","volume":"2","author":[{"given":"Rebecca S.","family":"Dickinson","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fiona","family":"Murphy","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Catherine","family":"Doherty","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7651-3457","authenticated-orcid":false,"given":"Sam","family":"Williams","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ananda","family":"Mirchandani","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joseph","family":"Willson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"John S.","family":"Scotti","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gail","family":"Preston","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christopher J.","family":"Schofield","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Moira K.B.","family":"Whyte","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9584-174X","authenticated-orcid":false,"given":"Sarah R.","family":"Walmsley","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"2560","published-online":{"date-parts":[[2017,10,26]]},"reference":[{"key":"ref-1","doi-asserted-by":"publisher","first-page":"91-100","DOI":"10.1080\/21548331.1976.11706983","article-title":"Pseudomonas: the compromised host.","volume":"11","author":"R Wood","year":"1976","journal-title":"Hosp Pract."},{"key":"ref-2","doi-asserted-by":"publisher","first-page":"213-219","DOI":"10.1136\/thx.53.3.213","article-title":"Lung infections. 3. 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Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1\/xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1\/iparadigms","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,10,10]],"date-time":"2019-10-10T14:24:09Z","timestamp":1570717449000},"score":1,"resource":{"primary":{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,10,26]]},"references-count":35,"URL":"https:\/\/doi.org\/10.12688\/wellcomeopenres.12871.1","relation":{"has-review":[{"id-type":"doi","id":"10.21956\/wellcomeopenres.13951.r27891","asserted-by":"subject"},{"id-type":"doi","id":"10.21956\/wellcomeopenres.13951.r28124","asserted-by":"subject"},{"id-type":"doi","id":"10.21956\/wellcomeopenres.13951.r27357","asserted-by":"subject"},{"id-type":"doi","id":"10.21956\/wellcomeopenres.13951.r28123","asserted-by":"subject"},{"id-type":"doi","id":"10.21956\/wellcomeopenres.13951.r27357","asserted-by":"object"},{"id-type":"doi","id":"10.21956\/wellcomeopenres.13951.r28124","asserted-by":"object"},{"id-type":"doi","id":"10.21956\/wellcomeopenres.13951.r27891","asserted-by":"object"},{"id-type":"doi","id":"10.21956\/wellcomeopenres.13951.r28123","asserted-by":"object"}]},"ISSN":["2398-502X"],"issn-type":[{"value":"2398-502X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,10,26]]},"assertion":[{"value":"Indexed","URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1#article-reports","order":0,"name":"referee-status","label":"Referee status","group":{"name":"current-referee-status","label":"Current Referee Status"}},{"value":"10.21956\/wellcomeopenres.13951.r27357, Susanne Schlisio, Department of Cell and Molecular Biology, Ludwig Institute for Cancer Research, Karolinska Institute, Stockholm, Sweden, 15 Nov 2017, version 1, indexed","URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1#referee-response-27357","order":0,"name":"referee-response-27357","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"Sarah Walmsley<\/b>; \nPosted: 16 Nov 2017<\/i>; We thank Dr Schlisio for her careful review of our manuscript and comments. Although the mean number of neutrophils following co-culture with mutant supernatants is lower than wildtype (1610±426 MT vs 2591±749) this does not reach statistical significance (P=0.89 by two way ANOVA).  We attribute this to significant cell loss with both wildtype and mutant supernatants under normoxic culture conditions given both strains of P. aeruginosa produce toxic levels of pyocyanin in normoxia.","URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1#referee-comment-3188","order":1,"name":"referee-comment-3188","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"10.21956\/wellcomeopenres.13951.r28123, Andrew S. Cowburn, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK, 22 Nov 2017, version 1, indexed","URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1#referee-response-28123","order":2,"name":"referee-response-28123","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"Sarah Walmsley<\/b>; \nPosted: 22 Nov 2017<\/i>; We thank Dr Cowburn for highlighting the importance of the observations detailed in the manuscript.  With respect to the time points studied, given we were already detecting a marked difference in BAL neutrophil counts at 24 hours, and that apoptotic cells are rapidly cleared in the in vivo setting, we chose to study a time point preceding one associated with significant cell loss (12 hours), to enable us to measure changes in surface apoptosis markers.","URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1#referee-comment-3201","order":3,"name":"referee-comment-3201","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"10.21956\/wellcomeopenres.13951.r27891, Beno\u00eet S. Marteyn, Pasteur Institute, Molecular Microbial Pathogenesis, Paris, France, 22 Nov 2017, version 1, indexed","URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1#referee-response-27891","order":4,"name":"referee-response-27891","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"Sarah Walmsley<\/b>; \nPosted: 22 Nov 2017<\/i>; We thank Dr Marteyn for the review of our manuscript. In vitro co-culture of neutrophils directly with pseudomonas species rapidly results in neutrophil loss. This is why we firstly explored the consequence of neutrophil culture with bacterial supernatants before undertaking in vivo experiments in which we were able to directly address the consequence of infection with the different strains of P. aeruginosa on neutrophil survival in a biological setting.   Due to the ability of pseudomonas to induce neutrophil apoptosis, this is a difficult question to directly address.  We would however argue that it is the ability of Pseudomonas to evade the host response that is critical in defining the outcome of the infection challenge, a concept supported by the published literature (Usher et al. JI 2002; Allen et al. JI 2005; Prince et al. JI 2008) and our in vivo observations.  We are sorry for any confusion caused, in the discussion we do actually state that \u201cuntil recently, the possibility that oxygen may also regulate the bacterial pathogens has not been considered\u201d and provide a number of references specific to Pseudomonas throughout the text that reference that capacity of hypoxia to alter pathogenicity (Scotti et al. PNAS 2014; Schaible et al. PLOS One 2013; Schaible et al. J Infect Dis 2017).","URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1#referee-comment-3202","order":5,"name":"referee-comment-3202","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"10.21956\/wellcomeopenres.13951.r28124, Stilla Frede, Department of Anesthesiology and Intensive Care Medicine, University Hospital Bonn, Bonn, Germany, 07 Dec 2017, version 1, indexed","URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1#referee-response-28124","order":6,"name":"referee-response-28124","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"Sarah Walmsley<\/b>; \nPosted: 12 Dec 2017<\/i>; We thank Dr Frede for her review of our manuscript.  In regard to the question raised, the pyocyanin concentrations reported in Figure 1D are expressed as ug\/ul and do not take into account differences in bacterial number under different conditions. In Figure 1F we show the viable bacterial count is greatly reduced for both the wt and mutant PSA strains when incubated in hypoxia compared to normoxia. If we correct for pyocynanin concentration per cfu we see an increased level of pyocyanin produced in the wt bacteria in hypoxia.","URL":"https:\/\/wellcomeopenresearch.org\/articles\/2-104\/v1#referee-comment-3266","order":7,"name":"referee-comment-3266","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"This study was supported by the Wellcome Trust [098516], a Senior Clinical Fellowship award to SRW, and [110086], a Postdoctoral Fellowship to AM. CJS thanks the Wellcome Trust and British Heart Foundation for support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.","order":8,"name":"grant-information","label":"Grant Information"},{"value":"This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.","order":0,"name":"copyright-info","label":"Copyright"}]}}