Objectives: To evaluate the in vitro microbicidal activity against Acanthamoeba castellanii of a murine monoclonal anti-idiotypic antibody (KTmAb) and a synthetic killer mimotope (KP), which mimic a yeast killer toxin (KT) characterized by a wide spectrum of antimicrobial activity through interaction with specific cell wall receptors, mainly constituted by b-glucans. Methods: Amoebicidal activity was investigated after incubation of trophozoites under different experimental conditions with laminarinase, KTmAb, KP and a scrambled decapeptide (SP). To confirm the specific interaction of KP with b-glucans, the experiments were also carried out in the presence of laminarin (b1-3-glucan) or pustulan (b1-6-glucan); both glucan molecules were co-incubated withKPor SP. Results: KTmAb and KP exhibited a time-dependent killing activity, in comparison with SP or heatinactivated KTmAb; this activity was completely abolished by pre-incubation with laminarin, but not by pustulan. Notably, in vitro amoebicidal activity was observed in the presence of laminarinase, an enzyme that specifically hydrolyses b-glucans. Furthermore, KP specifically inhibited the growth of Acanthamoeba on infected contact lenses and the remaining adherent KP-treated trophozoites appeared strongly damaged. Conclusions: The results indicate that the expression of b1-3-glucan receptors in the cell membrane is probably modulated during cell growth of A. castellanii and is critical for the killing activity of KT-like molecules. Our data confirm the broad antimicrobial spectra of KTmAb and KP, emphasize the crucial role of b1-3-glucan in microbial physiology and suggest the potential use of KTmAb and KP in the prevention and therapy of Acanthamoeba infections or in preventing Acanthamoeba contamination during storage of contact lenses.
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|Titolo:||In vitro acanthamoebicidal activity of a killer monoclonal amtibody and a synthetic peptide|
|Data di pubblicazione:||2006|
|Appare nelle tipologie:||1.1 Articolo in rivista|