Β-1, 3-Glucan recognition protein 3 activates the prophenoloxidase system in response to bacterial infection in Ostrinia furnacalis Guenée. (February 2018)

• Record Type: Journal Article
• Authors: Wu, Taoyan; Zhao, Ya; Wang, Zhenying; Song, Qisheng; Wang, Zengxia; Xu, Qiuwen; Wang, Yingjuan; Wang, Libao; Zhang, Yiqiang; Feng, Congjing
• Is Part Of: Developmental and comparative immunology. Volume 79(2018)
• Page Start: 31
• Page End: 43
• Publication Date: 2018-02
• Subjects: Pattern recognition receptor -- β-1, 3-Glucan recognition protein 3 -- Ostrinia furnacalis Guenée -- Bacterial infection -- Prophenoloxidase activating system; Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2017.10.004
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: Pattern recognition receptors (PRRs) are biosensor proteins that bind to non-self pathogen associated molecular patterns (PAMPs). β-1, 3-glucan recognition proteins (βGRPs) play an essential role in immune recognition and signaling pathway of insect innate immunity. Here, we report the cloning and characterization of cDNA of OfβGRP 3 from Ostrinia furnacalis larvae. The OfβGRP 3 contains 1455 bp open reading frame, encoding a predicted 484 amino acid residue protein. In hemocytes, the expression levels of OfβGRP 3 in Escherichia coli -challenged group were higher than those of Bacillus subtilis -challenged group at 2, 4, 8, 10 and 12 h post injection (HPI). In fat body, OfβGRP 3 expression in both B. subtilis and E. coli -challenged group was significantly higher than that in untreated group from 4 to 10 HPI, and then the expression continuously dropped from 12 to 36 HPI. The OfβGRP 3 expression in laminarin-injected group was higher than that in lipopolysaccharides (LPS)-injected group in various test tissues from 4 to 24 HPI. The LT50 of E. coli -infected OfβGRP 3-RNAi larvae (1.0 days) was significantly lower compared with that of E. coli infected wild-type larvae (3.0 days) ( p < 0.01). Only 10.2% Sephadex G50 beads (degree 3) were completely melanized in the larvae inoculated with OfβGRP 3 dsRNA, as compared to 48.8% in control larvae ( p < 0.01). A notable reduction in the PO activity and IEARase activity in hemolymph was also detected in the OfβGRP 3 knockdown larvae. Our study demonstrates that OfβGRP 3 is one of PRR members involved the PPO-activating system in O. furnacalis larvae. Highlights: Full-length cDNA of OfβGRP 3 was identified from Ostrinia furnacalis. In hemocytes, OfβGRP 3 expression in Escherichia coli -infected group was higher than that of Bacillus subtilis -infected group. The LT50 of E. coli -infected OfβGRP 3-RNAi larvae was significantly lower than that of E. coli -infected wild-type larvae. A notable reduction in the PO activity and IEARase activity in hemolymph was detected in the OfβGRP 3 knockdown larvae.