20‐hydroxyecdysone transcriptionally regulates humoral immunity in the fat body of Helicoverpa armigera. Issue 6 (15th September 2014)

• Record Type: Journal Article
• Authors: Wang, J‐L.; Chen, L.; Tang, L.; Zhao, H‐B.; Liu, X‐S.; Wang, Y‐F.
• Is Part Of: Insect molecular biology. Volume 23:Issue 6(2014:Dec.)
• Page Start: 842
• Page End: 856
• Publication Date: 2014-09-15
• Subjects: Insects -- Molecular aspects -- Periodicals; 595.7
• DOI: 10.1111/imb.12131
• Languages: English
• ISSNs: 0962-1075

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>20‐hydroxyecdysone (20E) increases its titre level during the wandering stage and influences innate immunity in many holometabolous insects. However, the function of 20E as an immune‐activator or ‐suppressor needs to be determined. Here, the transcriptome of the peptidoglycan‐challenged fat body of the cotton bollworm, <italic>Helicoverpa armigera</italic>, was analysed using Illumina sequencing technology. Overall, 32 073 unigenes were assembled with a mean length of 643 nucleotides. Gene expression dynamics in the fat body during the wandering stage and of peptidoglycan‐challenged individuals were investigated by the digital gene expression system. Pattern recognition receptors [such as <italic>peptidoglycan recognition protein B</italic> (<italic>PGRP B</italic>), <italic>PGRP S2</italic> <italic>precursor</italic>, <italic>C‐type lectin 5</italic>, <italic>hemolin</italic> and <italic>β‐1, 3‐glucan recognition protein 2a</italic>] and antimicrobial peptides (namely <italic>attacin</italic>, <italic>gloverin</italic>, <italic>gloverin precursor</italic>, <italic>gloverin‐like</italic>, <italic>cecropin 2</italic>, <italic>cecropin D</italic>, <italic>cecropin D‐like</italic> and <italic>i‐type lysozyme</italic>) significantly increased their mRNA levels during the wandering stage. 20E treatment significantly induced the expression of these genes. Antibacterial activities were also enhanced during the wandering stage and after 20E injections. <italic>Bacillus subtilis</italic> peptidoglycan induced the expression of <italic>PGRP D</italic>, <italic>PGRP B</italic>, <italic>PGRP S2</italic> <italic>precursor</italic>, <italic>gloverin</italic>, <italic>gloverin precursor</italic>, <italic>gloverin‐like</italic>, <italic>cecropin 2</italic>, <italic>cecropin D</italic> and <italic>lebocin‐like</italic> genes. These results demonstrate that 20E acts by enhancing humoral immunity in <italic>H. armigera</italic>.</p> </abstract>