Transcriptome and microRNAome elucidate the mechanism underlying the immunomodulatory effects of dietary CpG oligodeoxynucleotides (CpG ODNs) in Litopenaeus vannamei

Abstract

Dietary supplementary of CpG oligodeoxynucleotides (CpG ODNs) could regulate the composition of gut microbiota and augment its immune function in Litopenaeus vannamei. However, the molecular mechanism of CpG ODNs remains poorly understood, particularly in the transcription level. In this study, transcriptome and microRNA sequencing were conducted to analyze the alterations of related genes and regulators in hepatopancreas of shrimp following the administration of CpG ODNs. The results revealed a total of 7820 differentially expressed genes (DEGs) and 573 differentially expressed miRNAs, indicating that the miRNAs targeted 1263 DEGs. These DEGs were found to be involved in the regulation of multiple immune-related signaling pathways, such as ubiquinone biosynthesis, folate biosynthesis, glutathione metabolism and alpha-linolenic acid metabolism, which were significantly enhanced upon stimulation with CpG ODNs. The pathway analysis of DEGs and differential miRNA target genes revealed significant alterations in the TGF-β signaling pathway, FoxO signaling pathway, mTOR signaling pathway, autophagy, lysosome function, ubiquitin-mediated proteolysis, and cytochrome P450 metabolism. It can be concluded that CpG ODNs induced activation of immune-related signaling pathways, thereby eliciting a robust immune response and augmenting overall immunity. These findings establish a robust theoretical framework for the practical implementation of CpG ODNs in the L. vannamei aquaculture industry.