A C‐type lectin with dual‐CRD from Tribolium castaneum is induced in response to bacterial challenge

摘要: BACKGROUND C-type lectins (CTLs), a group of pattern recognition receptors, are involved in regulating the immune response insects and could be used as potential targets for pest control. However, information about roles CTLs innate immunity Tribolium castaneum, serious, worldwide that damages stored grain products, is relatively scarce. RESULTS Here, CTL with dual carbohydrate domains (CRDs) containing highly conserved WHD (Trp53 -His54 -Asp55 ) motif was identified T. castaneum named TcCTL3. Spatiotemporal analysis showed TcCTL3 expressed all developmental stages except early eggs, mainly distributed central nervous system hemolymph. The transcript levels were significantly increased after lipopolysaccharide (LPS) peptidoglycan (PGN) stimulation. Recombinant able to bind directly LPS, PGN tested bacteria induce broad spectrum microbial agglutination presence Ca2+ . binding shown through CRD1 domain When knocked down by RNA interference, expression nine antimicrobial peptides (AMPs) (attacin1, attacin2, attacin3, defensins1, defensins2, coleoptericin1, coleoptericin2, cecropins2 cecropins3) four transcription factors (TFs) (dif1, dif2, relish jnk) decreased under LPS stimulation, leading mortality when infected Gram-positive Staphylococcus aureus or Gram-negative Escherichia coli infection. CONCLUSION mediate via recognition, AMP expression. These findings indicate mechanism resisting provide an alternative molecular target © 2020 Society Chemical Industry.