SJL-1, a C-type lectin, acts as a surface defense molecule in Japanese sea cucumber, Apostichopus japonicus. (May 2018)

• Record Type: Journal Article
• Authors: Ono, Keisuke; Suzuki, Takuya Alan; Toyoshima, Youichi; Suzuki, Tomoya; Tsutsui, Shigeyuki; Odaka, Tomoyuki; Miyadai, Toshiaki; Nakamura, Osamu
• Is Part Of: Molecular immunology. Volume 97(2018:May)
• Page Start: 63
• Page End: 70
• Publication Date: 2018-05
• Subjects: C-type lectin -- SJL-1 -- Holothurian -- Apostichopus japonicus -- Integument -- Body surface; Immunochemistry -- Periodicals; Molecular biology -- Periodicals; Immunochemistry -- Periodicals; Allergy and Immunology -- Periodicals; Molecular Biology -- Periodicals; Immunochimie -- Périodiques; Biologie moléculaire -- Périodiques; Immunochemistry; Molecular biology; Periodicals; Electronic journals; 571.96
• DOI: 10.1016/j.molimm.2018.03.009
• Languages: English
• ISSNs: 0161-5890

Abstract

Highlights: A full length cDNA of SJL-1, a C-type lectin of Japanese sea cucumber, was sequenced. The gene is mainly expressed in the integument, tentacles and respiratory tree. SJL-1 is secreted onto the body surface of the animal. Recombinant SJL-1 can agglutinate Gram-positive and negative bacteria and yeast. Abstract: The surface defense molecules of aquatic invertebrates against infectious microorganisms have remained largely unexplored. In the present study, hemagglutinins were isolated from an extract of body surface layer of Japanese sea cucumber, Apostichopus japonicus, by affinity chromatography with fixed rabbit erythrocyte membranes. The N-terminal sequence of a 15-kDa agglutinin was almost identical with that of SJL-1, a C-type lectin formerly identified in this species. Because cDNA sequence and tissue distribution of SJL-1 have not been reported, we performed cDNA sequencing, gene expression analysis, and western blotting and immunohistochemical evaluation with anti-recombinant SJL-1 (rSJL-1) antibodies. The hemagglutinin gene was transcribed mainly in the integument, tentacles, and respiratory tree. Western blotting revealed that SJL-I is present in a body surface rinse, indicating that SJL-1 is secreted onto the body surface. SJL-1-positive cells scattered beneath the outermost layer of the integument were detected by immunohistochemistry. Furthermore, rSJL-1 agglutinated Gram-positive and Gram-negative bacteria, and yeast. These results indicate that SJL-1 acts as a surface defense molecule in A. japonicus .