PU.1 is involved in the immune response to Aspergillus fumigatus through upregulating Dectin-1 expression.
Invasive aspergillosis is a life-threatening disease, and its incidence has increased in the recent past. Dectin-1 recognizes β-glucans and mediates innate immune responses to Aspergillus fumigatus. Transcription factor PU.1 has been the focus of recent research due to its role in inflammation and infection. However, its role in Dectin-1 regulation during A. fumigatus infection remains to be elucidated.



THP-1 cells were stimulated with A. fumigatus conidia. We then used real-time RT-PCR, Western blot, and immunofluorescence assays to analyze the mRNA and protein levels and cellular distribution, respectively, of Dectin-1 and PU.1 in stimulated THP-1 cells. Additionally, we used the luciferase reporter assays, chromatin immunoprecipitation (ChIP) assays, electrophoretic mobility shift assays (EMSA), and RNA interference experiments to investigate the role of PU.1 in Dectin-1 regulation.



Our results revealed that Dectin-1 mRNA and protein levels as well as the PU.1 protein level were increased in THP-1 cells stimulated with A. fumigatus conidia, while the mRNA expression level did not significantly change between the stimulated and control groups. We also observed that PU.1 translocated into the nucleus in stimulated THP-1 cells. The results of the luciferase reporter assay showed that PU.1 promoted human Dectin-1 (hDectin-1) gene activity. ChIP and EMSA indicated that PU.1 could bind with hDectin-1 gene promoter at three potential transcription factor-binding sites (TFBSs). In addition, knockdown of PU.1 significantly decreased Dectin-1 expression.



This study demonstrated the novel role of PU.1 in the immune response to A. fumigatus through upregulation of Dectin-1 expression and its translocation to the nucleus in A. fumigatus-stimulated THP-1 cells.
Department of Respiratory and Critical Care Medicine, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, China.
Min
M
Wang
Southern Medical University, Guangzhou, China.
Zhicheng
Z
Liu
Southern Medical University, Guangzhou, China.
Chenyang
C
Liu
Department of Respiratory and Critical Care Medicine, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, China.
Ting
T
Wu
Department of Respiratory and Critical Care Medicine, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, China.
Feng
F
Cai
Department of Respiratory Medicine, BenQ Medical Center, Nanjing, China.
Quan
Q
Wang
Department of Respiratory and Critical Care Medicine, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, China. suxinjs@163.com.
Xin
X
Su
Department of Respiratory and Critical Care Medicine, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, China. shiyi56@126.com.
Yi
Y
Shi
D001228:Aspergillosis / Q000235:genetics / Q000276:immunology*; D001232:Aspergillus fumigatus / Q000276:immunology*; D015153:Blotting, Western; D002460:Cell Line; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics / Q000276:immunology*; D037181:Lectins, C-Type / Q000235:genetics / Q000276:immunology*; D009000:Monocytes / Q000276:immunology* / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000276:immunology*; D012333:RNA, Messenger / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D013172:Spores, Fungal; D015534:Trans-Activators / Q000235:genetics / Q000276:immunology*; D015854:Up-Regulation; D047071:beta-Glucans; D000099232:Proto-Oncogene Protein Spi-1; D000099181:Dectin-1
D037181:Lectins, C-Type; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; D047071:beta-Glucans; D000099232:Proto-Oncogene Protein Spi-1; C546929:CLEC7A protein, human; D000099181:Dectin-1
Aspergillus fumigatus; Dectin-1; Immunity; PU.1