title: A cysteine protease from Spirometra erinaceieuropaei plerocercoid is a critical factor for host tissue invasion and migration.
abstract: Sparganosis in humans caused by the plerocercoid larvae of Spirometra erinaceieuropaei is found worldwide, especially in Eastern Asia and the Far East. Previous studies have suggested that dissolution of plerocercoid body, plerocercoid invasion of host tissue, and migration are important processes for sparganosis progression. However, the mechanisms underlying these processes have yet to be determined. Here, we demonstrated the enzymatic property and involvement of a native 23kDa cysteine protease (Se23kCP), purified from plerocercoids, in sparganosis pathogenesis. Se23kCP is mature protease consisting of 216 amino acids and has a high sequence similarity with cathepsin L in various organisms. Se23kCP conjugated with N-glycans, which have a core fucose residue. Both cysteine and serine protease-specific activities were determined in Se23kCP and their optimal pHs were found to be different, indicating that Se23kCP has a wide range of substrate specificity. Se23kCP was secreted from tegumental vacuoles of the plerocercoid to host subcutaneous tissues and degraded human structural proteins, such as collagen and fibronectin. In addition, the plerocercoid body was lysed by Se23kCP, which facilitated larval invasion of host tissue. Our findings suggest that Se23kCP induces host tissue invasion and migration, and might be an essential molecule for sparganosis onset and progression.
authors.affiliation: Department of Molecular and Cellular Parasitology, Kitasato University Graduate School of Medical Sciences, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0373, Japan; Department of Parasitology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Daigo
authors.initials: D
authors.lastname: Tsubokawa
authors.affiliation: Department of Molecular and Cellular Parasitology, Kitasato University Graduate School of Medical Sciences, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0373, Japan; Department of Parasitology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hatta
authors.affiliation: Department of Parasitology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0374, Japan; Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Maeda
authors.affiliation: Department of Parasitology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Fusako
authors.initials: F
authors.lastname: Mikami
authors.affiliation: Department of Biochemistry, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Yukinobu
authors.initials: Y
authors.lastname: Goso
authors.affiliation: Department of Parasitology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Department of Parasitology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
authors.forename: M Abdul
authors.initials: MA
authors.lastname: Alim
authors.affiliation: Department of Molecular and Cellular Parasitology, Kitasato University Graduate School of Medical Sciences, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0373, Japan; Department of Parasitology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0374, Japan. Electronic address: tsujin@med.kitasato-u.ac.jp.
authors.forename: Naotoshi
authors.initials: N
authors.lastname: Tsuji
mesh_terms: D000818:Animals; D057056:Cysteine Proteases / Q000502:physiology*; D006790:Host-Parasite Interactions; D006801:Humans; D013031:Sparganosis / Q000469:parasitology*; D013146:Spirometra / Q000201:enzymology*
chemical_list: D057056:Cysteine Proteases
keywords: Body dissolution; Cysteine protease; Invasion; Migration; Plerocercoid; Spirometra erinaceieuropaei