Loss of Gliotoxin Biosynthesis Rewires Fungal Redox Metabolism and Impairs Macrophage Immune Competence in Aspergillus fumigatus

Aspergillus fumigatus (A. fumigatus) is a major opportunistic fungal pathogen, and gliotoxin (GT) is considered one of its key virulence factors. However, whether loss of GT biosynthesis reshapes fungal metabolism and thereby influences host immune responses remains unclear. Here, using the wild-type strain (WT), the gliP deletion strain (gliPΔ), and the complemented strain (gliPR), we performed untargeted metabolomic analyses of fungal hyphe and culture supernatants, integrated these data with transcriptomic profiling of infected THP-1 macrophages, and further validated the findings by exogenous GT stimulation, phagocytosis assays, and inflammatory cytokine analysis. We found that GT deficiency induced marked intracellular and extracellular metabolic reprogramming in A. fumigatus, with the most prominent changes involving amino acid metabolism, sulfur metabolism, coenzyme biosynthesis, and redox homeostasis. These alterations were accompanied by attenuated host immune and inflammatory transcriptional responses, suppression of oxidative phosphorylation- and ROS-related programs, and impaired phagocytic clearance. Together, our data indicate that GT biosynthesis is not only required for fungal metabolic homeostasis but is also closely linked to host immune competence, providing a new framework for understanding the contribution of GT to the pathogenesis of aspergillosis.