Lingna Xu,1,* Ren-ai Xu,2,* Dan Zhang,1 Shanshan Su,1 Hanyan Xu,1 Qing Wu,3 Yuping Li1 1Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China; 2Department of Pharmacy, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China; 3Department of Microbiology Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China *These authors contributed equally to this work Background: T helper 17 (Th17) lymphocytes play an important role in Aspergillus adaptive immune response against Aspergillus fumigatus, but there is little attention focused on the different types of immunosuppressive models in which invasive pulmonary aspergillosis (IPA) develops. In addition, the expression levels of signal transducer and activator of transcription 3 (STAT3)/retinoic acid-related orphan nuclear receptor gamma (RORγt)/interleukin (IL)-17A signaling pathway, which is involved in the regulation of Th17 cells, as well as whether there are differences between two types of IPA mice models, remain unknown. Materials and methods: Six to eight weeks old female BALB/c mice were treated with cortisone acetate or cyclophosphamide to establish the immunosuppressive mice models, and then, A. fumigatus inoculum was injected to form the IPA groups and sterile saline was injected to form the control groups. Flow cytometry was performed to measure the proportion of Th17 cells in CD4+ T cells in the peripheral blood, spleen, and lung of the mice. The expression of IL-17A, RORγt, and STAT3 mRNA was detected by real-time polymerase chain reaction. Concentrations of IL-6 in the plasma and bronchoalveolar lavage fluid were measured by enzyme-linked immunosorbent assay. Results: The proportion of Th17 in the peripheral blood and lung tissue in neutropenic IPA miceshowed a more significant increase than in non-neutropenic IPA mice (P
