STAT2-IRF1-ISG15-Associated Temporal Immune Reprogramming in Macrophages during Aspergillus fumigatus Infection.

Aspergillus fumigatus poses a critical threat to immunocompromised hosts through invasive aspergillosis, with mortality rates reaching 50-90%. Although macrophages initiate early antifungal defenses via pattern recognition receptors, the temporal dynamics of immune reprogramming remain incompletely characterized. This study integrated time-series transcriptomics (GSE202286) of human monocyte-derived macrophages exposed to A. fumigatus conidia (0-8 h) with experimental validation to delineate immune-phase transitions and identify candidate regulatory modules. Bioinformatics analysis revealed a progressive increase in differential gene expression, peaking at 8 h (2,636 upregulated and 1,940 downregulated genes). Gene set enrichment analysis (GSEA) showed early enrichment of TNF-α/NF-κB signaling (NES = 2.37, 2 h), followed by a prominent interferon-γ response at 8 h (NES = 2.37) that coincided with ongoing inflammatory pathway activity. Temporal clustering identified 448 dynamically regulated genes associated with oxidative stress response (GO:0006979) and exploratory C-type lectin receptor-related pathway patterns (KEGG hsa04625). Protein interaction and transcription factor analyses predicted STAT2 as a candidate upstream regulator associated with IRF1 and ISG15. qRT-PCR validation in THP-1-derived macrophages showed sequential mRNA induction, with STAT2 peaking at 2 h, IRF1 at 4 h, and ISG15 remaining elevated through 8 h. A representative Western blot further supported this temporal pattern, showing early STAT2 phosphorylation, subsequent IRF1 protein induction, and later accumulation of free ISG15. Together, these findings suggest a STAT2-IRF1-ISG15-associated transcriptional program that may contribute to the transition from an inflammatory to an interferon-augmented macrophage response during A. fumigatus challenge.