Innate Lymphoid Cells Integrate Sensing and Plasticity to Control Fungal Infections [whole lung tissue after ILC transfer_Afu infected]

Innate lymphoid cells (ILCs) are crucial regulators of tissue immunity, yet their role in antifungal defense remains incompletely understood. Through our findings, we demonstrate that pulmonary ILCs can sense fungal pathogens by recognizing fungal cell wall components via pattern recognition receptors, leading to the activation and type-1 polarization in vitro. Mechanistically, we identify Syk/Akt-dependent signaling as one of the key drivers of ILC activation upon fungal encounters. Aspergillus fumigatus infection reshapes this response in vivo, where elevated TGF-ß and IL-1ß levels facilitate a shift from type-1 ILC activity to IL-17A release. Ultimately, IL-17-producing ILCs are crucial in resolving the infection and restoring normal tissue homeostasis. Moreover, adoptive transfer models in lymphocyte-deficient Rag2-/-?c-/- mice reveal that ILCs restrain excessive inflammation while hindering fungal clearance, highlighting their dual role in regulating antifungal immunity. Remarkably, ILCs lacking the non-receptor tyrosine kinase Tec disrupts caspase-8 activation, leading to enhanced proliferation of type-1 ILCs. Consequently, improved fungal clearance enhances host survival by strengthening antifungal immunity. Our findings uncover hitherto unrecognized roles of ILCs as fungal sensors and early modulators of antifungal immunity. Therefore, targeting Tec kinase signaling in ILCs holds great promise as a therapeutic option to enhance antifungal immunity, especially in patients at risk for invasive A. fumigatus infections. Overall design: Bulk RNAseq of whole lung tissue samples from infected Rag2-/-Il2rg-/- mice to investigate the impact of transferred ILCs on Aspergillosis outcome. Outcome of Aspergillus infection was compared between wild type ILC-receiving mice (+wt ILCs), Tec-kinase deficient ILC receiving mice (+Tec-/- -ILCs) and mice not receiving transfer (no transfer controls). Pulmonary ILC subsets were MACS-enriched (lineage cell depletion) and expanded in vitro for 14 days. Mice received sorted pulmonary ILC subsets at 14 days and 3 days before infection. Mice were intranasally infected with 3*10^7 Aspergillus fumigatus spores (ATCC204305). Lung tissue samples were extracted after 17 hours and stored in RNA-later at -80°C. Each sample represents biological replicates