Identification and characterization of two novel C‐type lectins from the larvae of housefly, Musca domestica L.

作者：Jing Zhou, Nai‐ Nai Fang, Ya Zheng, Kai Yu Liu, Bin Mao, Li‐ Na Kong, Chen Ya, Hui Ai · 发表于：Archives of Insect Biochemistry and Physiology · 年份：2018 · DOI：10.1002/arch.21467 · 被引用次数：23 · 研究领域：Invertebrate Immune Response Mechanisms、Mosquito-borne diseases and control、Insect symbiosis and bacterial influences

Abstract Lectins and antimicrobial peptides (AMPs) are widely distributed in various insects and play crucial roles in primary host defense against pathogenic microorganisms. Two AMPs (cecropin and attacin) have been identified and characterized in the larvae of housefly. In this study, two novel C‐type lectins (CTLs) were obtained from Musca domestica , while their agglutinating and antiviral properties were evaluated. Real‐time PCR analysis showed that the mRNA levels of four immune genes ( MdCTL1 , MdCTL2 , Cecropin , and Attacin ) from M. domestica were significantly upregulated after injection with killed Gram‐negative Escherichia coli . Moreover, purified MdCTL1‐2 proteins can agglutinate E. coli and Staphylococcus aureus in the presence of calcium ions, suggesting their immune function is Ca 2+ dependent. Sequence analysis indicated that typical WND and QPD motifs were found in the Ca 2+ ‐binding site 2 of carbohydrate recognition domain from MdCTL1‐2, which was consistent with their agglutinating activities. Subsequently, antiviral experiments indicated that MdCTL1‐2 proteins could significantly reduce the infection rate of Spodoptera frugiperda 9 cells by the baculovirus Autographa californica multicapsid nucleopolyhedrovirus, indicating they might play important roles in insect innate immunity against microbial pathogens. In addition, MdCTL1‐2 proteins could effectively inhibit the replication of influenza H 1 N 1 virus, which was similar to the effect of ribavirin....