title: Functional roles of mannose-binding protein in the adhesion, cytotoxicity and phagocytosis of Acanthamoeba castellanii.
abstract: Acanthamoeba castellanii is a single-celled protozoan that is widely distributed in the environment and is a well-known of causing human keratitis, a vision-threatening infection. In this study, an ethyl methane sulfonate (EMS) and a selection of saccharide were applied to A. castellanii by chemical mutagenesis. To understand the functional roles of a mannose-binding protein (MBP). A. castellanii were treated with methyl-alpha-D-mannopyranoside abbreviated Man, with and without the EMS pre-treatment, and their adhesion and cytotoxicity were analyzed, using a human brain microvascular endothelial cell (HBMEC) as the target cell. Both EMS and Man mutants exhibited significantly decreased levels of MBP expression and cytotoxicity to HBMEC, but showed similar levels of binding to HBMEC, as compared with the wild type. Of interest was that the exogenous mannose inhibited amoebae (i.e., Man mutant) binding to the HBMEC by <20%. Only the mutant Man exhibited a significant decrease in bacterial uptake, as compared to the wild type, 0.020 vs 0.032 (p<0.05) and proteolytic activity. The results showed that MBP should be clearly provided as the pathogenic target candidate, to further target-based therapy, but EMS mutation should not be associated with initial adhesion and phagocytosis of A. castellanii.
authors.affiliation: Department of Microbiology, Ajou University School of Medicine, Suwon 443-721, Republic of Korea.
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Abdul
authors.initials: A
authors.lastname: Matin
authors.forename: Ho-Joon
authors.initials: HJ
authors.lastname: Shin
authors.forename: Hyun
authors.initials: H
authors.lastname: Park
authors.forename: Kyung-Tae
authors.initials: KT
authors.lastname: Yoo
authors.forename: Xi-Zhe
authors.initials: XZ
authors.lastname: Yuan
authors.forename: Kwang Sik
authors.initials: KS
authors.lastname: Kim
authors.forename: Suk-Yul
authors.initials: SY
authors.lastname: Jung
mesh_terms: D048248:Acanthamoeba castellanii / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D001921:Brain / Q000098:blood supply; D002448:Cell Adhesion; D016923:Cell Death; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology; D048168:Escherichia coli K12 / Q000276:immunology; D006801:Humans; D037601:Mannose-Binding Lectin / Q000502:physiology*; D055806:Microvessels / Q000166:cytology; D016296:Mutagenesis; D010587:Phagocytosis
chemical_list: D037601:Mannose-Binding Lectin