Effect of ovotransferrin and lactoferrins on Chlamydophila psittaci adhesion and invasion in HD11 chicken macrophagesDelphine Sylvie Anne Beeckman, Caroline M.A.D. Van Droogenbroeck, Bart J.A. De Cock, Patrick Van Oostveldt and Daisy C.G. Vanrompay
Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium
(Received 22 December 2006; accepted 12 April 2007 ; published online 10 July 2007)
Abstract - The effect of ovotransferrin (ovoTF), human lactoferrin (hLF) and bovine lactoferrin (bLF) on the obligate intracellular pathogen Chlamydophila (Cp.) psittaci was evaluated using a model of Buffalo Green Monkey kidney (BGM) cells and HD11 chicken macrophages as artificial hosts. Firstly, the effect of transferrins on the infectivity of the bacteria was evaluated. Pre-incubation of Cp. psittaci with 0.5 to 5 mg/mL ovoTF prior to infecting BGM cells significantly lowered the infection rate (P < 0.05). For both lactoferrins, the infection rate could only be reduced with 5 mg/mL, albeit not significantly as compared to the infection rate created by the untreated bacteria. Secondly, transferrins were tested for their ability to influence bacterial adhesion and entry in HD11 cells. Maximal non-cytotoxic and non-bactericidal concentrations of 0.05 mg/mL ovoTF and 0.5 mg/mL hLF and bLF were used. Overall, ovoTF was more effective than human and bovine LF in inhibiting bacterial irreversible attachment and cell entry and the latter was accompanied by a dose-dependent reduction of actin recruitment at the bacterial entry site. However, once bacteria had entered HD11 cells, transferrins had apparently no effect on intracellular replication. The present findings suggest a possible role for transferrins and especially ovoTF, in preventing avian Cp. psittaci infections.
Key words: ovotransferrin / lactoferrin / Chlamydia / Chlamydophila psittaci
Corresponding author: Delphine.Beeckman@UGent.be
© INRA, EDP Sciences 2007