Negative Regulation Roquin RNA Binding Proteins STING Dependent Innate Immune Response Of Drosophila

Drosophila melanogaster utilizes innate immune response to defend against exogenous pathogens.The molecular regulation mechanism of the process is evolutionarily conserved.Research of the regulatory mechanisms of Drosophila innate immunity is greatly significant for understanding the modulation of the human innate immunity and the pathogenesis of related diseases.Stimulator of interferon genes(STING)is an adaptor protein that plays an important role in the activation of type ? interferons in response to cytosolic nucleic acid ligands.To explore novel regulators in the STING-dependent innate immune response in Drosophila,we used Drosophila as experimental materials to perform a series of exploratory experiments from molecular,cellular and individual levels using double-stranded RNA-mediated gene expression silencing technique and the dual-luciferase reporter system.The main findings are as follows :1.Knockdown experiments was performed on 9 genes encoding the ubiquitin ligase such as echinus(CG2904),usp16(CG4165),smurf(CG4943),pellino(CG5212),usp47(CG5486),diap2(CG8293),dtraf2(CG10961),roquin(CG16807)and usp10(CG32479)in the S2 cells in vitro through the double-stranded RNA-mediated gene expression silencing technique and the dual-luciferase reporter system.The results suggested a negative correlation between roquin(CG16807)and the STING signaling pathway,suggesting that roquin may be a negative regulator of STING innate immune signaling pathway.2.The luciferase reporting system and qRT-PCR experiments showed that knockdown roquin gene level in S2 cells could significantly promote the expression of antimicrobial peptide gene attacinC and diptericinA mRNA levels,and over-expression of roquin in S2 cells could significantly inhibit the elevated levels of these antimicrobial peptides,which further proved that roquin negative regulation of STING innate immune signaling.3.Listeria infection experiments showed that knocking down of roquin markedly elevated the expression levels of anti-microbial peptides and inhibited the proliferation of Listeria,Thus increasing the survival rates post pathogenic infection.Taken together,our results suggested that the RNA-binding protein Roquin negatively regulates the STING-dependent innate immune response in Drosophila.In view of the high correlation between Drosophila genes and human genes,this study provides a theoretical basis for further development of treatments for STING-related innate immune diseases in humans.