{"title":"Enhanced immunoprotection against Acinetobacter baumannii infection: Synergistic effects of Bap and BauA in a murine model","authors":"Mobina Mansouri , Masoomeh Sadeghpoor , Abolfazl Jahangiri , Mohammad Hossein Ghaini , Iraj Rasooli","doi":"10.1016/j.imlet.2023.08.004","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><p>The rise of multi-drug resistant <em>Acinetobacter baumannii</em> poses a grave threat to hospital settings, resulting in increased mortality rates and garnering global attention. The formation of biofilms facilitated by biofilm-associated protein (Bap) and the iron absorption capabilities mediated by Baumannii acinetobactin utilization A (BauA) contribute to the persistence and survival of multidrug-resistant strains. In this study, we aimed to investigate the potential of disrupting the function of BauA and Bap simultaneously as a strategy for controlling <em>A. baumannii</em>.</p></div><div><h3>Methods</h3><p>Recombinant Bap and BauA were expressed, purified, and subcutaneously administered individually and in combination to BALB/c mice. Subsequently, mice were intraperitoneally challenged with <em>A. baumannii</em>, and the bacterial load and tissue damage in the spleen, lung, and liver were assessed. Serum samples were evaluated to determine antibody titers in surviving mice.</p></div><div><h3>Results</h3><p>Specific IgG antibodies were significantly increased. A combination of the antigens resulted in enhanced titer of specific IgGs in comparison to either BauA or Bap alone. The antibodies remained stable over a seven-month period. The combination of Bap and BauA exhibited superior immunoprotection against <em>A. baumannii</em> infection compared to individual administration, resulting in a further reduction in bacterial load in the liver, spleen, and lungs. The histopathological analysis demonstrated successful protection of the tissues against <em>A. baumannii</em>-induced damage upon administration of the two immunogens.</p></div><div><h3>Conclusions</h3><p>The combination of Bap and BauA has the potential to target a broader range of <em>A. baumannii</em> strains, including those expressing either Bap or BauA, thereby increasing its efficacy against a diverse array of strains.</p></div>","PeriodicalId":13413,"journal":{"name":"Immunology letters","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Immunology letters","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0165247823001426","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"IMMUNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background
The rise of multi-drug resistant Acinetobacter baumannii poses a grave threat to hospital settings, resulting in increased mortality rates and garnering global attention. The formation of biofilms facilitated by biofilm-associated protein (Bap) and the iron absorption capabilities mediated by Baumannii acinetobactin utilization A (BauA) contribute to the persistence and survival of multidrug-resistant strains. In this study, we aimed to investigate the potential of disrupting the function of BauA and Bap simultaneously as a strategy for controlling A. baumannii.
Methods
Recombinant Bap and BauA were expressed, purified, and subcutaneously administered individually and in combination to BALB/c mice. Subsequently, mice were intraperitoneally challenged with A. baumannii, and the bacterial load and tissue damage in the spleen, lung, and liver were assessed. Serum samples were evaluated to determine antibody titers in surviving mice.
Results
Specific IgG antibodies were significantly increased. A combination of the antigens resulted in enhanced titer of specific IgGs in comparison to either BauA or Bap alone. The antibodies remained stable over a seven-month period. The combination of Bap and BauA exhibited superior immunoprotection against A. baumannii infection compared to individual administration, resulting in a further reduction in bacterial load in the liver, spleen, and lungs. The histopathological analysis demonstrated successful protection of the tissues against A. baumannii-induced damage upon administration of the two immunogens.
Conclusions
The combination of Bap and BauA has the potential to target a broader range of A. baumannii strains, including those expressing either Bap or BauA, thereby increasing its efficacy against a diverse array of strains.
期刊介绍:
Immunology Letters provides a vehicle for the speedy publication of experimental papers, (mini)Reviews and Letters to the Editor addressing all aspects of molecular and cellular immunology. The essential criteria for publication will be clarity, experimental soundness and novelty. Results contradictory to current accepted thinking or ideas divergent from actual dogmas will be considered for publication provided that they are based on solid experimental findings.
Preference will be given to papers of immediate importance to other investigators, either by their experimental data, new ideas or new methodology. Scientific correspondence to the Editor-in-Chief related to the published papers may also be accepted provided that they are short and scientifically relevant to the papers mentioned, in order to provide a continuing forum for discussion.