Cryptococcus neoformans is a causative agent of global fungal meningoencephalitis, responsible for over 180,000 annual deaths. In analyzing this pathogen, we performed in vivo transcription profiling to monitor 180 transcription factors (TFs) during infection. Our focus was on 12 TFs that were notably induced in host-mimicking conditions (HMC). To determine which host factors contribute to gene induction during infection, we dissected HMC signals into components of temperature, carbon, and nitrogen starvation. Remarkably, we identified three distinct cues significantly influencing gene regulation. Temperature upshift markedly induced the expression of six genes. Similarly, glucose starvation and nitrogen starvation highly induced the expression of six and nine genes, respectively. Furthermore, deleting MLN1 resulted in growth defects under carbon starvation conditions with alternative disaccharide carbon sources (maltose, trehalose, sucrose), excluding glucose. Also, in vivo studies using a mouse model demonstrated attenuated virulence and reduced brain fungal burdens in mice inoculated with mln1Δ. In conclusion, our systematic dissection of host-signaling cues provides deeper insight into the complex signaling pathways that modulate host-pathogen interactions in C. neoformans.
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