title: Expression profiles of six novel C-type lectins in response to bacterial and 20E injection in the cotton bollworm (Helicoverpa armigera).
abstract: C-type lectins can act as pattern recognition receptors (PRRs) and play an important role in innate immunity. Two C-type lectins (HaCTL1 and HaCTL2) have been previously identified in the cotton bollworm (Helicoverpa armigera). Here we isolate six C-type lectins from H. armigera (HaCTL3, 4, 5, 6, 7 and 8). All six new HaCTLs encode a signal peptide (or partial signal peptide) and complete tandem carbohydrate-recognition domains (CRDs). HaCTL4, 5, 6, 7 and 8 mRNA increased in the fat body after injection with both killed Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, whereas HaCTL3 mRNA was upregulated following E. coli injection only. Recombinant HaCTL3 exhibited agglutinating activity against both Gram-negative and Gram-positive bacteria in a calcium-dependent manner. Agglutination inhibitory analysis indicated that rHaCTL3 recognizes maltose, trehalose, peptidoglycan and lipopolysaccharides. HaCTL3 and HaCTL8 mRNA showed upregulation while HaCTL4, 5, and 6 mRNA downregulation post 20-Hydroxyecdysone (20E) injection. Our results indicate that the six novel C-type lectins of H. armigera may play important roles in defending against bacteria as PRRs and the hormone 20E can function in regulating immunity through lectins.
authors.affiliation: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Science, Central China Normal University, Wuhan 430079, China. galin66@163.com
authors.forename: Jia-Lin
authors.initials: JL
authors.lastname: Wang
authors.forename: Xu-Sheng
authors.initials: XS
authors.lastname: Liu
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Hao-Bin
authors.initials: HB
authors.lastname: Zhao
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D005216:Fat Body / Q000737:chemistry; D020869:Gene Expression Profiling; D019476:Insect Proteins / Q000235:genetics* / Q000276:immunology; D037181:Lectins, C-Type / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D009036:Moths / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D010802:Phylogeny; D051192:Receptors, Pattern Recognition / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment
chemical_list: D019476:Insect Proteins; D037181:Lectins, C-Type; D051192:Receptors, Pattern Recognition