title: A novel C-type lectin with triple carbohydrate recognition domains has critical roles for the hard tick Haemaphysalis longicornis against Gram-negative bacteria.
abstract: C-type lectins (CLecs) play an important role in innate immunity against invaders. In this study, a novel CLec was identified from Haemaphysalis longicornis ticks (HlCLec). HlCLec contains a signal peptide and a transmembrane region. Interestingly, HlCLec possesses three dissimilar carbohydrate recognition domains (CRDs). Each CRD contains the mutated motif of Ca(2+)-binding site 2. HlCLec mRNA was up-regulated during blood feeding, and had highest expression in the midgut and ovary. HlCLec localization was also confirmed by immunofluorescent antibody test (IFAT). HlCLec was found on the cell membrane and basal lamina of midgut and ovary. In addition, the recombinant HlCLec and individual CRDs demonstrated direct binding activity to Escherichia coli and Staphylococcus aureus; however, no growth inhibition activity was observed. Furthermore, E. coli injection after silencing of HlCLec caused drastic reduction in survival rate of ticks. These results strongly suggest the key role of HlCLec in tick innate immunity against Gram-negative bacteria.
authors.affiliation: Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, Kagoshima 890-0065, 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: Division of Molecular Functions of Food, Department of Biochemistry and Biotechnology, Kagoshima University, Korimoto, Kagoshima 890-0065, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Miyata
authors.affiliation: Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, Kagoshima 890-0065, Japan; Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan.
authors.forename: Kodai
authors.initials: K
authors.lastname: Kusakisako
authors.affiliation: Department of Veterinary Paraclinical Sciences, College of Veterinary Medicine, University of the Philippines Los Baños, Los Baños, Laguna 4031, Philippines.
authors.forename: Remil Linggatong
authors.initials: RL
authors.lastname: Galay
authors.affiliation: Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, Kagoshima 890-0065, Japan; Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan.
authors.forename: Melbourne Rio
authors.initials: MR
authors.lastname: Talactac
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Rika
authors.initials: R
authors.lastname: Umemiya-Shirafuji
authors.affiliation: Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, Kagoshima 890-0065, Japan; Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Mochizuki
authors.affiliation: Zen-noh Institute of Animal Health, Ooja, Sakura, Chiba 285-0043, Japan.
authors.forename: Kozo
authors.initials: K
authors.lastname: Fujisaki
authors.affiliation: Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, Kagoshima 890-0065, Japan; Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan. Electronic address: tetsuya@ms.kagoshima-u.ac.jp.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002241:Carbohydrates / Q000276:immunology; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000254:growth & development*; D016905:Gram-Negative Bacterial Infections / Q000276:immunology*; D007113:Immunity, Innate / Q000235:genetics; D026863:Ixodidae / Q000276:immunology*; D037181:Lectins, C-Type / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D034741:RNA, Small Interfering / Q000235:genetics; D051192:Receptors, Pattern Recognition / Q000235:genetics / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000254:growth & development*; D019076:Transgenes / Q000235:genetics
chemical_list: D002241:Carbohydrates; D037181:Lectins, C-Type; D034741:RNA, Small Interfering; D051192:Receptors, Pattern Recognition
keywords: C-type lectin; Gram-negative bacteria; Innate immunity; Recombinant; Tick