title: Functional analysis of membrane-bound complement regulatory protein on T-cell immune response in ginbuna crucian carp.
abstract: Complements have long been considered to be a pivotal component in innate immunity. Recent researches, however, highlight novel roles of complements in T-cell-mediated adaptive immunity. Membrane-bound complement regulatory protein CD46, a costimulatory protein for T cells, is a key molecule for T-cell immunomodulation. Teleost CD46-like molecule, termed Tecrem, has been newly identified in common carp and shown to function as a complement regulator. However, it remains unclear whether Tecrem is involved in T-cell immune response. We investigated Tecrem function related to T-cell responses in ginbuna crucian carp. Ginbuna Tecrem (gTecrem) proteins were detected by immunoprecipitation using anti-common carp Tecrem monoclonal antibody (mAb) and were ubiquitously expressed on blood cells including CD8α(+) and CD4(+) lymphocytes. gTecrem expression on leucocyte surface was enhanced after stimulation with the T-cell mitogen, phytohaemagglutinin (PHA). Coculture with the anti-Tecrem mAb significantly inhibited the proliferative activity of PHA-stimulated peripheral blood lymphocytes, suggesting that cross-linking of Tecrems on T-cells interferes with a signal transduction pathway for T-cell activation. These findings indicate that Tecrem may act as a T-cell moderator and imply that the complement system in teleost, as well as mammals, plays an important role for linking adaptive and innate immunity.
authors.affiliation: Laboratory of Marine Biochemistry, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan; Aquaculture Department, Fisheries and Marine Science Faculty, Halu Oleo University, Kendari 93232, Indonesia.
authors.forename: Indriyani
authors.initials: I
authors.lastname: Nur
authors.affiliation: Laboratory of Marine Biochemistry, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan; Department of Internal Medicine, Infectious and Fish diseases, Faculty of Veterinary Medicine, El-Mansoura University, Egypt.
authors.forename: Nevien K
authors.initials: NK
authors.lastname: Abdelkhalek
authors.affiliation: Laboratory of Marine Biochemistry, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Shiori
authors.initials: S
authors.lastname: Motobe
authors.affiliation: Laboratory of Marine Biochemistry, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Nakamura
authors.affiliation: Laboratory of Marine Biochemistry, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Tsujikura
authors.affiliation: Laboratory of Marine Biochemistry, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan. Electronic address: somamoto@agr.kyushu-u.ac.jp.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Somamoto
authors.affiliation: Laboratory of Marine Biochemistry, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Nakao
mesh_terms: D056704:Adaptive Immunity / Q000276:immunology*; D000818:Animals; D002347:Carps / Q000276:immunology*; D003165:Complement System Proteins / Q000276:immunology; D005434:Flow Cytometry; D007113:Immunity, Innate / Q000276:immunology*; D047468:Immunoprecipitation; D051916:Membrane Cofactor Protein / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D051916:Membrane Cofactor Protein; D003165:Complement System Proteins
keywords: CD46-like protein; Ginbuna crucian carp; Membrane-bound complement regulatory protein; PHA; T-cell; Teleost