title: CD44 mediated hyaluronan adhesion of Toxoplasma gondii-infected leukocytes.
abstract: Toxoplasma gondii is an obligate intracellular apicomplexan parasite that infects humans and animals. Ingested parasites cross the intestinal epithelium, invade leukocytes and are then disseminated to peripheral organs. However, the mechanism of extravasation of the infected leukocytes remains poorly understood. In this study, we demonstrate that T. gondii-invaded human and mouse leukocytes express higher level of CD44, a ligand of hyaluronan (HA), and its expression on myeloid and non-myeloid leukocytes causes T. gondii-invaded human and mouse leukocyte to adhere to HA more effectively than non-invaded leukocytes. The specific adherence of parasite-invaded leukocytes was inhibited by anti CD44 antibody. Leukocytes of CD44 knockout mice did not show parasite-invaded leukocyte specific adhesion. Our results indicate that parasite-invaded leukocytes, regardless of whether myeloid or not, gain higher ability to adhere to HA than non-invaded leukocytes, via upregulation of CD44 expression and/or selective invasion to CD44 highly expressing cells. The difference in ability to adhere to HA between parasite-invaded cells and non-invaded neighboring cells might facilitate effective delivery of parasite-invaded leukocytes to the HA-producing endothelial cell surface and/or HA-rich extra cellular matrix.
authors.affiliation: Department of Veterinary Parasitology, United Graduate School of Veterinary Sciences, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: Division of Experimental Animals, Center for Promotion of Medical Research and Education, Graduate School of Medicine, Nagoya University, Tsurumai 65 Showa-ku, Nagoya 466-8550, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Unno
authors.affiliation: Department of Veterinary Parasitology, United Graduate School of Veterinary Sciences, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan.
authors.forename: Minami
authors.initials: M
authors.lastname: Baba
authors.affiliation: Division of Experimental Animals, Center for Promotion of Medical Research and Education, Graduate School of Medicine, Nagoya University, Tsurumai 65 Showa-ku, Nagoya 466-8550, Japan.
authors.forename: Tamio
authors.initials: T
authors.lastname: Ohno
authors.affiliation: Department of Veterinary Parasitology, United Graduate School of Veterinary Sciences, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan; Department of Veterinary Parasitology, Faculty of Applied Biological Science, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Kitoh
authors.affiliation: Department of Veterinary Parasitology, United Graduate School of Veterinary Sciences, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan; Department of Veterinary Parasitology, Faculty of Applied Biological Science, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan. Electronic address: atakashi@gifu-u.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takashima
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism*; D006820:Hyaluronic Acid / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000469:parasitology* / Q000502:physiology; D051379:Mice; D013154:Spleen / Q000166:cytology; D014122:Toxoplasma / Q000502:physiology*
chemical_list: D018960:Hyaluronan Receptors; D006820:Hyaluronic Acid
keywords: Adhesion; CD44; Dissemination; Hyaluronan; PBMC; Toxoplasma gondii