Activator protein 1 is triggered by Aspergillus fumigatus beta-glucans surface-exposed during specific growth stages

作者：Toyotome Takahito^*; Adachi Yoshiyuki; Watanabe Akira; Ochiai Eri; Ohno Naohito; Kamei Katsuhiko

来源：Microbial Pathogenesis, 2008, 44(2): 141-150.

DOI：10.1016/j.micpath.2007.08.015

• Aspergillus fumigatus
• Activator protein 1
• beta-Glucan
• Dectin-1
• Fungal infection

Aspergillus fumigatus has been shown to trigger the activation of nuclear factor-kappa B (NF-kappa B), but it remains unclear whether other transcription factors are also induced following infection by this organism. In this study, we demonstrated that A. fumigatus also triggers activator protein 1 (AP-1), a transcription factor that plays an important role during the production of cytokines and chemokines. Swollen conidia strongly induce the activation of AP-1, and more than 80% of these were stained positively with anti-beta-glucan antibodies by fluorescence microscopy. Hyphae were also stained with anti-beta-glucan antibodies, albeit significantly weaker compared with swollen conidia. Furthermore, our present findings also showed that A. fumigatus triggers the activation of AP-1 in a dectin-1 (receptor for beta-glucan)-dependent manner. These data thus suggest that AP-1 is triggered by beta-glucan recognition on the surface of A. fumigatus. We also showed that Syk tyrosine kinase is required for AP-1 induction in this pathway. We therefore speculate that the dectin-1/Syk/AP-1 signaling pathway plays an important role in the host defense response to fungal infection.

• 出版日期2008-2