BACKGROUND: Acinetobacter baumannii, an important nosocominal pathogen, causes various human infections like meningitis, bacteremia and pneumonia. The aim of this study was to produce nanobodies derived from camel heavy chain antibodies (HcAb) against a conserved region of the biofilm associated protein (Bap) of A. baumannii, by phage display technique. METHODS: A camel was immunized with the purified recombinant protein expressed from the conserved region of Bap and polyclonal antibody production was confirmed by ELISA. After RNA extraction from peripheral lymphocytes, cDNA was prepared and a phagemid library was constructed. RESULTS: Phage particles encoding nanobodies were produced by infecting transformed cells with a M13K07 helper phage. A total of six panning rounds were performed to select high affinity clones. Screening of high affinity monoclonal nanobodies was performed using phage-ELISA. A clone with the highest absorption in monoclonal phage-ELISA was selected for soluble expression of the desired nanobody. CONCLUSIONS: This is the first report on the expression and production of nanobodies against Bap. Increasing trends of drug resistance have shifted the focus to the role of antibodies in diagnosis and treatment of human diseases. Similarities of the produced VHH to human VH, makes the role of this nanobody promising in immunotherapy.
BACKGROUND:Acinetobacter baumannii, an important nosocominal pathogen, causes various humaninfections like meningitis, bacteremia and pneumonia. The aim of this study was to produce nanobodies derived from camel heavy chain antibodies (HcAb) against a conserved region of the biofilm associated protein (Bap) of A. baumannii, by phage display technique. METHODS: A camel was immunized with the purified recombinant protein expressed from the conserved region of Bap and polyclonal antibody production was confirmed by ELISA. After RNA extraction from peripheral lymphocytes, cDNA was prepared and a phagemid library was constructed. RESULTS: Phage particles encoding nanobodies were produced by infecting transformed cells with a M13K07 helper phage. A total of six panning rounds were performed to select high affinity clones. Screening of high affinity monoclonal nanobodies was performed using phage-ELISA. A clone with the highest absorption in monoclonal phage-ELISA was selected for soluble expression of the desired nanobody. CONCLUSIONS: This is the first report on the expression and production of nanobodies against Bap. Increasing trends of drug resistance have shifted the focus to the role of antibodies in diagnosis and treatment of human diseases. Similarities of the produced VHH to human VH, makes the role of this nanobody promising in immunotherapy.
Authors: Kristian Daniel Ralph Roth; Esther Veronika Wenzel; Maximilian Ruschig; Stephan Steinke; Nora Langreder; Philip Alexander Heine; Kai-Thomas Schneider; Rico Ballmann; Viola Fühner; Philipp Kuhn; Thomas Schirrmann; André Frenzel; Stefan Dübel; Maren Schubert; Gustavo Marçal Schmidt Garcia Moreira; Federico Bertoglio; Giulio Russo; Michael Hust Journal: Front Cell Infect Microbiol Date: 2021-07-07 Impact factor: 5.293