Aureobasidium pullulans-cultured fluid induces IL-18 production, leading to Th1-polarization during influenza A virus infection. (3rd October 2017)

• Record Type: Journal Article
• Authors: Fujikura, Daisuke; Muramatsu, Daisuke; Toyomane, Kochi; Chiba, Satoko; Daito, Takuji; Iwai, Atsushi; Kouwaki, Takahisa; Okamoto, Masaaki; Higashi, Hideaki; Kida, Hiroshi; Oshiumi, Hiroyuki
• Is Part Of: Journal of biochemistry. Volume 163:Number 1(2018:Jan.)
• Page Start: 31
• Page End: 38
• Publication Date: 2017-10-03
• Subjects: adjuvant -- Aureobasidium pullulans -- infection -- influenza A virus -- innate immunity; Biochemistry -- Periodicals; Biochemistry -- Periodicals; Electronic journals; 572.05
• DOI: 10.1093/jb/mvx062
• Languages: English
• ISSNs: 0021-924X

Abstract

Abstract: Several microbial molecules with pathogen-associated molecular patterns stimulate host innate immune responses. The innate immune system plays a crucial role in activating acquired immune response via cytokine production and antigen presentation. Previous studies have shown that Aureobasidium pullulans- cultured fluid (AP-CF), which contains β-glucan, exhibits adjuvant activity and renders mice resistance to influenza A virus infection; however, the underlying mechanism remains elusive. In this study, we investigated the innate immune response to AP-CF. We found that intraperitoneal administration of AP-CF increased the serum level of IL-18 and the number of splenic IFN-γ producing CD4 + cells during influenza A virus infection. The adjuvant effect of AP-CF was distinct from that of alum, which is known to have the ability to stimulate a Th2 immune response. In addition, AP-CF injection barely increased the number of peritoneal neutrophils and inflammatory macrophages, whereas alum injection markedly increased the number of neutrophils and inflammatory macrophages, suggesting that AP-CF is a weak inducer of inflammation compared to alum. AP-CF induced IL-18 production by DC2.4 cells, a dendritic cell line, and by peritoneal exudate cells that include peritoneal macrophages. Collectively, our findings indicate that AP-CF is an adjuvant that promotes the Th1 response during influenza A virus infection.