Genome-Wide Gene Expression Analysis of Mtb-Infected DC Highlights the Rapamycin-Driven Modulation of Regulatory Cytokines via the mTOR/GSK-3β Axis

Abstract

In human primary dendritic cells (DC) rapamycin—an autophagy inducer and protein synthesis inhibitor—overcomes the autophagy block induced by Mycobacterium tuberculosis (Mtb) and promotes a Th1 response via IL-12 secretion. Here, the immunostimulatory activity of rapamycin in Mtb-infected DC was further investigated by analyzing both transcriptome and translatome gene profiles. Hundreds of differentially expressed genes (DEGs) were identified by transcriptome and translatome analyses of Mtb-infected DC, and some of these genes were found further modulated by rapamycin. The majority of transcriptome-associated DEGs overlapped with those present in the translatome, suggesting that transcriptionally stimulated mRNAs are also actively translated. In silico analysis of DEGs revealed significant changes in intracellular cascades related to cytokine production, cytokine-induced signaling and immune response to pathogens. In particular, rapamycin treatment of Mtb-infected DC caused an enrichment of IFN-β, IFN-λ and IFN-stimulated gene transcripts in the polysome-associated RNA fraction. In addition, rapamycin led to an increase of IL-12, IL-23, IL-1β, IL-6, and TNF-α but to a reduction of IL-10. Interestingly, upon silencing or pharmacological inhibition of GSK-3β, the rapamycin-driven modulation of the pro- and anti-inflammatory cytokine balance was lost, indicating that, in Mtb-infected DC, GSK-3β acts as molecular switch for the regulation of the cytokine milieu. In conclusion, our study sheds light on the molecular mechanism by which autophagy induction contributes to DC activation during Mtb infection and points to rapamycin and GSK-3β modulators as promising compounds for host-directed therapy in the control of Mtb infection.

NCoR1 controls immune tolerance in conventional dendritic cells by fine-tuning glycolysis and fatty acid oxidation

“…Studies have reported on the complex immune regulatory networks perturbed by Mtb infection to increase its survival. Mtb infection up-regulates mTOR activity and upon treatment with rapamycin, IL-12 production and Th1 response goes high to clear the pathogen [ 58 ] . The former results exhibited active perturbation of HIF-1α and CPT1a in NCoR1 depleted DCs promoted a Th1 response via reduction of IL-10 to IL-12 cytokine balance.…”

GSK-3α/β Activity Negatively Regulates MMP-1/9 Expression to Suppress Mycobacterium tuberculosis Infection

“…It is reported that Mtb tyrosine phosphatase PtpA led to dephosphorylation of GSK-3α ( 7 ). In human primary dendritic cells (DC), Mtb infection modulated pro- and anti-inflammatory cytokine production through mTOR/GSK-3β axis ( 8 ). However, the exact efficacy and molecular mechanisms as how GSK-3α/β interacts with Mtb infection in Mφs remain undefined.…”

Integrated bioinformatics analysis of dendritic cells hub genes reveal potential early tuberculosis diagnostic markers

“…The number of samples in non-infected (NI), live MTB-infected, and heat-inactivated (HI) MTB-infected group were 17, respectively, at multiple time points in hours (h), 2 h, 18 h, 48 h, and 72 h. DCs were infected with MTB for time series at a multiplicity of infection (MOI) of 1 or with HI MTB at MOI of 5. GSE163531 [ 12 ] dataset was obtained from GPL20265 platform and 8 DC samples from blood were treated with or without virulent MTB H37Rv (ATCC 27,294) at MOI of 1 bacterium/cell for 16 h. DCs were generated by culturing CD14 + monocytes with 50 ng/ml granulocyte-macrophage colony-stimulating factor (GM-CSF) and 1000 U/ml IL-4. Detailed information about these datasets were listed in Table 1 .…”