title: A single-CRD C-type lectin is important for bacterial clearance in the silkworm.
abstract: C-type lectins (CTLs) depend on the carbohydrate-recognition domain (CRD) to recognize carbohydrates by a Ca(2+)-dependent mechanism. In animals, CTLs play critical roles in pathogen recognition, activation of the complement system and signaling pathways. Immulectins (Dual-CRD CTLs) in lepidopteran are involved in recognizing pathogens. However, little is known about the immune-related functions of insect single-CRD CTLs. Here, we reported the characterization of C-type lectin-S3 (CTL-S3), a single-CRD CTL from the domesticated silkmoth Bombyx mori (Lepidoptera: Bombycidae). The ORF of CTL-S3 gene is 672 bp, which encodes a putative protein of 223 amino acids. CTL-S3 gene was expressed in a variety of tissues. Levels of CTL-S3 mRNA in fertilized eggs and whole larvae were elevated upon bacterial challenges. CTL-S3 was secreted to larval hemolymph. The recombinant protein (rCTL-S3) binds to bacterial cell wall components and bacteria. CTL-S3 inhibited the growth of Bacillus subtilis and caused agglutination of Staphylococcus aureus. More importantly, CTL-S3 facilitated the rapid clearance of Escherichia coli and Staphylococcus aureus from the body cavity of larvae. Taken together, our results suggested that CTL-S3 may function as an opsonin in larval hemolymph to enhance the clearance of pathogens.
authors: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, China.
authors: Ming-Yue
authors: MY
authors: Zhan
authors: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, China.
authors: Toufeeq
authors: T
authors: Shahzad
authors: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, China.
authors: Pei-Jin
authors: PJ
authors: Yang
authors: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, China.
authors: Su
authors: S
authors: Liu
authors: Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO 64110, USA.
authors: Xiao-Qiang
authors: XQ
authors: Yu
authors: School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, China. Electronic address: rxj@ahau.edu.cn.
authors: Xiang-Jun
authors: XJ
authors: Rao
mesh_terms: D000371:Agglutination; D000818:Animals; D001424:Bacterial Infections / Q000276:immunology*; D058491:Bacterial Load; D012831:Bombyx / Q000276:immunology*; D003001:Cloning, Molecular; D003167:Complement Activation / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D006458:Hemolymph / Q000382:microbiology / Q000502:physiology*; D007113:Immunity, Innate; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D037181:Lectins, C-Type / Q000235:genetics / Q000378:metabolism*; D009895:Opsonin Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D019476:Insect Proteins; D037181:Lectins, C-Type; D009895:Opsonin Proteins
keywords: C-type lectin; Insect immunity; Silkworm