Microrna-142-3p Inhibits Ifn-Gamma Production Via Targeting Of Rictor In Aspergillus Fumigatus Activated Cd4(+) T Cells

Background: Aspergillus fumigatus (AFE) is a well-adapted, opportunistic fungus that causes a severe and commonly fatal disease, wherein IFN-gamma is one of the most important protective cytokines. The aim of this study was to investigate the microRNA expression profile and explore the underlying mechanism during infection with AFE.Methods: CD4(+) T cells were activated by co-culturing with dendritic cells (DCs), which were pre-treated with AFE. Next, we performed microRNA microarray expression profiles of activated and control T cells, following which, miRNA-142-3P was selected. To explore the effect of miR-142-3P on T cell activation, miRNA-142-3P expression was disrupted by transient transfection with miR-142-3P mimic or inhibitor. Then, levels of RICTOR, phosphorylated AKT and IFN-gamma were detected via Western blotting and qPCR respectively. We further used siRNA to decrease RICTOR expression and determined the role played by RICTOR in miR-142-3P mediated-IFN-gamma expression by qPCR following AFE-mediated T cell activation.Results: The heat-map of miRNA expression profiles showed that 54 microRNAs (miRNAs) were filtered, the levels of which, were significantly different between CD4(+) T cells activated by AFE and control T cells, in which microRNA-142-3 was involved. Forced expression of miRNA-142-3P dramatically suppressed RICTOR levels, phosphorylated AKT and IFN-gamma in AFE activated T cells. Conversely, loss of miRNA-142-3P elevated RICTOR levels, phosphorylated AKT and IFN-gamma. Notably, RICTOR deficiency decreased AKT phosphorylation levels and IFN-gamma secretion.Conclusions: Observations indicated that down-regulation of microRNA-142-3p enhanced IFN-gamma expression, and did so by promoting RICTOR expression in CD4(+) T cells activated by AFE.