Transcriptome and translatome profiling of Mtb-infected human DC identifies GSK-3beta as a molecular switch of rapamycin-driven immune stimulation

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 Th1 response via IL-12 secretion. Here, the immunostimulatory activity of rapamycin in Mtb-infected DC was investigated by analyzing the transcriptome and the translatome profiles. Several differentially expressed genes (DEGs) were found in transcriptome and translatome of Mtb-infected DC, showing an additional increase in presence of rapamycin, which was instead ineffective in uninfected cells. The majority of DEGs identified in the translatome resulted also present in the transcriptome-modulated genes, suggesting that both RNAs are actively translated mRNAs. The DEG in silico analysis showed 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 a significant enrichment of IFN-beta, IFN-lambda and IFN-stimulated genes in the polysome-associated RNA fraction. In addition, IL-12, IL-23, IL-1B, IL-6, and TNF-A were induced at RNA and protein level by rapamycin in Mtb-infected DC, while IL-10 was reduced. Interestingly, upon siRNA or pharmacologically GSK-3beta inhibition, rapamycin-driven modulation of the pro- and anti-inflammatory cytokine balance was lost, thus indicating that in Mtb-infected DC GSK-3beta functions as molecular switch for the regulation of cytokine milieu. In conclusion, our study sheds light on the molecular mechanism by which autophagy contributes to DC activation during Mtb infection and highlights that rapamycin and its analogs as well as GSK-3beta modulators are promising compounds for host-directed therapy in the control of Mtb infection.

ORGANISM(S): Homo sapiens

PROVIDER: GSE163531 | GEO | 2021/04/12

REPOSITORIES: GEO