Korean J Parasitol.  2012 Dec;50(4):365-369.

Effects of Mannose on Pathogenesis of Acanthamoeba castellanii

• Yoo KT
• Jung SY

Abstract

Acanthamoeba spp. are single-celled protozoan organisms that are widely distributed in the environment. In this study, to understand functional roles of a mannose-binding protein (MBP), Acanthamoeba castellanii was treated with methyl-alpha-D-mannopyranoside (mannose), and adhesion and cytotoxicity of the amoeba were analyzed. In addition, to understand the association of MBP for amoeba phagocytosis, phagocytosis assay was analyzed using non-pathogenic bacterium, Escherichia coli K12. Amoebae treated with mannose for 20 cycles exhibited larger vacuoles occupying the most area of the amoebic cytoplasm in comparison with the control group amoebae and glucose-treated amoebae. Mannose-selected amoebae exhibited lower levels of binding to Chinese hamster ovary (CHO) cells. Exogenous mannose inhibited >50% inhibition of amoebae (control group) binding to CHO cells. Moreover, exogenous mannose inhibited amoebae (i.e., man-treated) binding to CHO cells by <15%. Mannose-selected amoebae exhibited significantly decreased cytotoxicity to CHO cells compared with the control group amoebae, 25.1% vs 92.1%. In phagocytic assay, mannose-selected amoebae exhibited significant decreases in bacterial uptake in comparison with the control group, 0.019% vs 0.03% (P<0.05). Taken together, it is suggested that mannose-selected A. castellanii trophozoites should be severely damaged and do not well interact with a target cell via a lectin of MBP.

Keyword

Acanthamoeba castellanii; mannose-binding protein; adhesion; cytotoxicity; Escherichia coli K12

MeSH Terms

Acanthamoeba castellanii/drug effects/metabolism/*pathogenicity
Amebiasis/*parasitology
Animals
CHO Cells
Cell Adhesion/drug effects
Cell Survival
Cricetinae
Cricetulus
Escherichia coli K12/metabolism
Female
Mannose/*pharmacology
Mannose-Binding Lectin/*metabolism
Phagocytosis
Protozoan Proteins/metabolism
Mannose
Mannose-Binding Lectin
Protozoan Proteins