IFIT2-induced transcriptomic changes in Mycobacterium tuberculosis infected macrophages.

Interferon-induced protein with tetratricopeptide repeat 2 (IFIT2) is known for its antiviral activity and has recently been implicated in the defense against Mycobacterium tuberculosis (M. tb). This study employed global transcriptomics to investigate the downstream effects of IFIT2 induction in THP-1 macrophages infected with R179 M. tb, aiming to elucidate its role and downstream contributing factors that aid it in intracellular M. tb killing. Using a vector-based overexpression approach, IFIT2 expression was induced in THP-1 cells infected with R179 M. tb, followed by RNA extraction 12 hours post-infection and AmpliSeq-based targeted transcriptome sequencing. Bioinformatics analysis identified 282 differentially expressed genes (DEGs), of which 189 were upregulated and 90 were downregulated (FDR <0.05). Filtering for highly significant DEGs (|log(2)(fold change) | > 1.5) yielded 70 genes, predominantly upregulated, with functional enrichment in pathways such as defense response to viruses and cytokine-mediated signaling. Signaling pathway impact analysis highlighted pathway activation and inhibition of the tuberculosis (TB) pathway. RT-qPCR validation confirmed the upregulation of selected DEGs (ISG15, CMPK2, RSAD2, IFI44L, IFI44), corroborating the AmpliSeq data. This study provides comprehensive insights into the transcriptomic profile induced by IFIT2 in TB, revealing critical downstream contributors and pathways that underpin IFIT2's ability to combat M. tb infection.