Identification of a C-type lectin from Antheraea pernyi, which may associate with the immune response to pathogens

•We firstly identified a C-type Lectin from Antheraea pernyi (ApCTL).•ApCTL can mediate immune response to pathogens in A. pernyi.•ApCTL can be induced significantly by nuclear polyhedrosis virus (NPV) and E. coli.•ApCTL can promote the agglutination of E. coli in Ca2 +-dependent manner and has the bacteriolytic activity on E. coli.

C-Type lectins (CTLs) are carbohydrate-recognition proteins and play critical roles in innate immunity. In this study, we characterized a CTL from Antheraea pernyi, named ApCTL, which has two carbohydrate-recognition domains (CRDs). A fragment of 1017 bp cDNA of ApCTL was isolated, which constituted 927 bp open reading frame (ORF), and it encoded putative protein of 308 amino acids. The recombinant protein of ApCTL was expressed in Escherichia coli, and anti-ApCTL antibodies were prepared. ApCTL gene was constitutively expressed in a variety of tissues while it showed a higher expression level in fat body than other tissues. Protein and mRNA levels of ApCTL in fat body and hemolymph were elevated upon nuclear polyhedrosis virus (NPV) and E. coli challenges. Recombinant ApCTL increased the agglutination of E. coli in a Ca2 +-dependent manner and had the bacteriolytic activity on E. coli. Our results suggested that ApCTL may play critical roles in pathogen recognition and could be involved in the innate immunity of A. pernyi.

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