title: The distribution pattern of α2,3- and α2,6-linked sialic acids affects host cell preference in Toxoplasma gondii.
abstract: Tachyzoites of Toxoplasma gondii, an obligate intracellular parasite, actively invade almost all types of nucleated cells. However, T. gondii tachyzoites preferentially infect particular types of animal tissue cells. The mechanism underlying the host cell preference of T. gondii is not yet known. In this study, we found that enzymatic removal of α2,3- but not α2,6-linked sialic acids on the surface of Vero cells decreased T. gondii tachyzoite adhesion or invasion to the treated cells. Although Chinese hamster ovary (CHO) cells express only α2,3-linked sialic acid, a genetically modified CHO cell line constructed by transfection with the α2,6-sialiltransferase gene contains subpopulations with a variety of expression patterns of α2,3- and α2,6-linked sialic acids. When T. gondii tachyzoites were added to the modified CHO cells, the tachyzoites preferentially attached to cells belonging to a subpopulation of cells that highly expressed α2,3-linked sialic acids. Additionally, multiple regression analysis performed to analyse the relationship between the amount of α2,3-linked/α2,6-linked sialic acids and parasite-expressed fluorescence intensity suggested that more tachyzoites adhered to individual α2,3-linked sialic acid rich-cells than to α2,3-linked sialic acid-poor/null cells. The results of confocal laser microscopy confirmed this finding. These results indicate that the host cell preference of T. gondii was, at least partially, affected by the distribution pattern of α2,3-, but almost never α2,6-linked sialic acids on host cells.
authors.affiliation: Department of Veterinary Parasitology, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
authors.forename: Minami
authors.initials: M
authors.lastname: Baba
authors.affiliation: National Institute for Basic Biology, Okazaki Institute for Integrative Bioscience, 5-1 Higashiyama, Okazaki 444-8787, Japan.
authors.forename: Masanao
authors.initials: M
authors.lastname: Sato
authors.affiliation: Department of Veterinary Parasitology, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Kitoh
authors.affiliation: Department of Veterinary Parasitology, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan. Electronic address: atakashi@gifu-u.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takashima
mesh_terms: D000268:Adhesiveness; D000818:Animals; D016466:CHO Cells / Q000737:chemistry*; D002460:Cell Line; D002469:Cell Separation; D002522:Chlorocebus aethiops; D006224:Cricetinae; D003412:Cricetulus; D005434:Flow Cytometry; D006790:Host-Parasite Interactions; D018613:Microscopy, Confocal; D009439:Neuraminidase / Q000378:metabolism; D012044:Regression Analysis; D012794:Sialic Acids / Q000737:chemistry* / Q000235:genetics; D012799:Sialyltransferases / Q000235:genetics*; D014122:Toxoplasma / Q000502:physiology*; D014709:Vero Cells / Q000737:chemistry*; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
chemical_list: D012794:Sialic Acids; D012799:Sialyltransferases; D009439:Neuraminidase; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
keywords: Cell adhesion; Sialic acid; Toxoplasma gondii; α2,3-linkage; α2,6-linkage