The microRNA pathway activation in insect cell model upon Autographa californica multiple nucleopolyhedrovirus infection

Background: The immune system of insects exerts fundamentally different antiviral mechanisms than mammals. MicroRNAs (miRNAs) play vital roles in developing insect antiviral immunity. MiRNAs expression profiles of insects changed significantly during baculovirus infection. Methods: Differential expression profiles of miRNAs in Spodoptera frugiperda were monitored by next-generation sequencing (NGS) and RT-qPCR during Autographa californica multiple nucleopolyhedrovirus (AcMNPV) infection. The transcription levels of genes were detected by RT-qPCR. The 50% tissue culture infective dose (TCID50) endpoint dilution assay was used to determine the proliferation of progeny virus. Results: NGS revealed that 49 miRNAs were differentially expressed in Sf9 cells, and 10 of them were significantly up-or down-regulated. Though RT-qPCR analysis, we observed the similar trends for the expression patterns of significantly differentially expressed miRNAs from NGS. Moreover, the transcription levels of core genes, Exportin5, Dicer1, and Argonaute1, in miRNA biogenesis pathways were significantly increased after AcMNPV infection. For five selected miRNAs, miR-34-5p could regulate the proliferation of baculovirus progeny virus and energy metabolism. Conclusion: The miRNAs biogenesis pathway in Sf9 cells plays an important role and may be stimulated to resist AcMNPV infection. This work provides evidence for the molecular mechanism of baculovirus-insect interaction and offers novel ideas and directions for green pest control technology.

Automated summary

By analyzing the expression of miRNAs in Spodoptera frugiperda cells (Sf9 cells), it was found that there were 49 differentially expressed miRNAs during Autographa californica multiple nucleopolyhedrovirus (AcMNPV) infection, among which 10 miRNAs showed significant changes in expression. The transcription levels of core genes in the miRNA biogenesis pathway were significantly increased after AcMNPV infection. This study reveals the important role of the miRNA biogenesis pathway in Sf9 cells in resisting AcMNPV infection.