J Fungi (Basel) 2:32. 2021 Karnam et al. This content is usually distributed under the terms of the Creative Commons Attribution 4.0 International license. FIG?S2. Inhibition of Wnt/-catenin signaling reduces the expression of live conidia-induced maturation markers on human DCs. DCs (0.5??106 cells/mL) were cultured with GM-CSF and interleukin 4 (IL-4) and were either unstimulated (CA) or treated with DMSO or Wnt inhibitor (Wnt Inhi) for 2 h, followed by stimulation with live conidia (LC; = 500) for 48 h. The expression of CD80, CD86, CD274, CD40, and HLA-DR on DCs was analyzed by flow cytometry. Data (mean SEM) are from 4 donors. *, swollen conidia-stimulated DCs. DCs (0.5??106 cells/mL) were cultured with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4 and were either unstimulated (CA) or exposed to LiCl inhibitor for 2 h, followed by stimulation with swollen conidia (SC). After 48 h, DCs were washed and cocultured with autologous naive CD4+ T cells for 5 days. Frequencies (mean SEM; required C-type lectin receptors and promoted Treg polarization via the induction of programmed death-ligand 1 on DCs. Further investigation around the identity of fungal molecular patterns has revealed that this cell wall polysaccharides -(1, 3)-glucan and -(1, 3)-glucan, but not chitin, possess the capacity to activate the -catenin pathway. Our data suggest that the Wnt/-catenin pathway is usually a potential therapeutic target to selectively suppress the Treg response and to sustain the protective Th1 response in the context of invasive aspergillosis caused by is an omnipresent airborne fungal pathogen. Human lungs are constantly exposed to conidia (asexual spores, and are airborne) through breathing. Although inhaled conidia are usually eliminated in healthy individuals, Eperezolid they may cause hypersensitization, severe asthma with fungal sensitization, allergic bronchopulmonary aspergillosis, colonization of altered respiratory epithelium, and aspergilloma in existing pulmonary lesions; they can lead to life-threatening invasive aspergillosis in immunocompromised hosts (1,C5). Innate immune cells, including macrophages, dendritic cells (DCs), and neutrophils, are involved in antifungal activity against conidial clearance, whereas germinating morphotypes of are destroyed by neutrophils through the release of iron chelator (as iron is essential for germination) and reactive oxygen species (ROS) and by forming neutrophil extracellular traps. DCs can also internalize both conidial and hyphal morphotypes of and could undergo functional maturation (6). Being professional antigen-presenting cells, DCs are also involved in polarizing distinct CD4+ T-cell responses (7,C10). Upon fungal encounter, DCs engage their various pattern recognition receptors (PRRs) to recognize the evading pathogen (11,C13). These contamination. On the other hand, Th1 cells have a major role for the induction of protective immune responses (14,C17). Although Tregs Eperezolid are immunosuppressive and promote chronic and persistent contamination, they are also critical for preventing inflammation-associated tissue damage (18, 19). Therefore, the balance Eperezolid between Th1 and Treg responses is critical for the protective immune response against contamination of human/mouse cornea or human monocyte cell line THP-1 induced the production of Wnt5a, the Wnt ligand, in a dectin-1- IgM Isotype Control antibody (PE-Cy5) and LOX-1-dependent manner (32). Contamination of mouse peritoneal macrophages with different fungal pathogens or with curdlan [linear -(1, 3)-glucan produced by as a model, here we show that fungal species activate the Wnt/-catenin pathway in human DCs, along with the secretion of Wnt ligands Wnt1 and Wnt7a. Inhibition of the Wnt pathway prior to stimulation Eperezolid with resulted in decreased DC maturation and selective inhibition of anti-inflammatory cytokine IL-10 without affecting the secretion of most of the proinflammatory cytokines. Abrogation of the Wnt/-catenin pathway in DCs also led to reduced Treg polarization without altering the polarization of other CD4+ T-cell subsets. Mechanistically, induction of the -catenin pathway by in DCs required C-type lectin receptors and mediated Treg responses via induction of programmed death ligand 1 (PD-L1) on DCs. Dissection of the identity of pathogen-associated molecular patterns (PAMPs) revealed that this cell wall polysaccharides -(1, 3)-glucan and -(1, 3)-glucan, but not chitin, possess the capacity to activate the -catenin pathway in.