Transcriptome profiling reveals a novel mechanism of antiviral immunity upon Sacbrood virus infection in honey bee larvae (Apis cerana)

Authors: GUO, YULONG - Chinese Academy Of Agricultural Sciences; ZHANG, ZHENGYI - Chinese Academy Of Agricultural Sciences; WANG, LIUHAO - Chinese Academy Of Agricultural Sciences; LI, KAI - Chinese Academy Of Agricultural Sciences; YAO, JUN - Chinese Academy Of Agricultural Sciences; YANG, HUIPENG - Chinese Academy Of Agricultural Sciences; HUANG, JIAXING - Chinese Academy Of Agricultural Sciences; WU, JIE - Chinese Academy Of Agricultural Sciences; Chen, Yanping - Judy; LI, JILIAN - Chinese Academy Of Agricultural Sciences

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/2021
Publication Date: 4/30/2021
Citation: Guo, Y., Zhang, Z., Wang, L., Li, K., Yao, J., Yang, H., Huang, J., Wu, J., Chen, Y., Li, J. 2021. Transcriptome profiling reveals a novel mechanism of antiviral immunity upon Sacbrood virus infection in honey bee larvae (Apis cerana). Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2021.615893.
DOI: https://doi.org/10.3389/fmicb.2021.615893

Interpretive Summary: Bees play a vital role in agriculture by providing pollination service to more than 100 important crops. The sacbrood virus causes a serious infectious disease in honey bees, but the mechanisms underlying the action of the virus' infection remain uncharacterized. In this study, we employed an advanced technology to explore the complex interactions between honey bees and the virus and identified various genes that are involved in the insect's immune responses to the disease-based infection. These genes may be potential targets for antiviral therapy to provide a new strategy for controlling viral infections in honey bees. The information gained from this work should be of interest to researchers, graduate students, and beekeepers who are seeking new solutions for disease prevention and treatment in honey bees.

Technical Abstract: The honey bee is one of the most important pollinators in agricultural system and is responsible for pollinating a third of all food we eat. Sacbrood virus is a member of the virus family Iflaviridae and affects honey bee larvae and causes devastating disease in the Asian honey bees, Apis cerana. Chinese Sacbrood virus (CSBV) is a geographic strain of Sacbrood virus identified in China. CSBV has resulted in mass death of honey bee in China in recent years. However, the molecular mechanism underlaying CSBV infection in A. cerana has remained unelucidated. In this present study, we employed RNA-Seq to study the host transcriptional responses to CSBV infection in A. cerana larvae, and were able to identify genome-wide differentially expressed genes associated with the viral infection. There were 2534 differentially expressed genes (DEGs) that were identified in response to the virus infection, with some DEGs involved in a variety of host immune signaling pathways including Toll pathway, RNAi, Imd, and endocytosis. Particularly, the expression of genes encoding antimicrobial peptides (abaecin, apidaecin, hymenoptaecin, defensin) and proteins acting in the RNAi process such as Dicer-like and Ago2 were found to be significantly upregulated in CSBV infected larvae. Moreover, the expression of Sirtuin genes, a family of signaling proteins involved in metabolic regulation, apoptosis and intracellular signaling was found to be upregulated, providing the first evidence of the involvement ofSirtuin signaling pathway in immune response of honey bees to CSBV infection. The results obtained from this study provide novel insights into the molecular mechanism and immune responses involved in CSBV infection, which in turn will contribute to the development of diagnostics and treatment for the disease.