Shahed University

Immunogenicity of Cork and Loop Domains of Recombinant Baumannii acinetobactin Utilization Protein in Murine Model

Iraj Rasooli | Hamid Esmaeilkhani | Masoomeh Hashemi | Shahram Nazarian | Fatemeh Sefid
URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=116625
Date :  2019/07/03
Publish in :    Avicena Journal of Medical Biotechnology


Keywords :Immunogenicity, Domains, Recombinant, Baumannii, acinetobactin, Utilization, Murine

Abstract :
Background: Acinetobacter baumannii (A. baumannii) is a bothersome fatal patho-gen, particularly in healthcare system. Persistence and successful invasion of A. bau-mannii in vertebrate host cells largely depends on iron acquisition methods. Sidero-phore molecules and Iron-Regulated Outer Membrane Proteins (IROMPs) are the two essential members of iron acquisition system. Siderophores are secreted by bacteria to bind peripheral ferric iron and the IROMPs are expressed at the bacterial outer mem-brane as the receptor of ferric-siderophore complex. BauA is the corresponding sider-ophore receptor of A. baumannii. In this study, an attempt was made to assess the immunogenicity of antigenic domains of BauA which could be effective in iron up-take restriction and protection against bacterial invasion of the host cells. Methods: The antigenic domains of bauA were amplified from A. baumannii ATCC-19606. The PCR products were ligated into pET32a and expressed in Escherichia coli (E. coli) BL21 (DE3). Purification of recombinant domains was done by Nickel-Nitri-lotriacetic Acid (Ni-NTA) affinity chromatography. The recombinant domains were injected into BALB/C mice separately and in combination. Sero-reactivities of the re-combinant proteins and mouse challenge tests were carried out. Results: The antibodies raised in mice could successfully recognize and bind antigenic domains. Passive immunization studies accomplished by immune rabbit serum inhib-ited the establishment of infection in mice. Conclusion: The results adapted from the present study disclose the protective role of functional domains of BauA, especially the cork domain, suggesting a novel recombi-nant immunogen candidate.