Oral

[O3-D-AM1-03] Actinomyces oris MG-1 induces inflammatory response in dTHP-1 macrophage cells

〇Zixin Wu¹, Hiroki Takigawa², Hugo Maruyama², Takayuki Nambu², Chiho Mashimo², Toshinori Okinaga² (1. Dept Bacteriol, Osaka Dent Univ Grad Sch Dent, 2. Dept Bacteriol, Osaka Dent Univ)

Keywords:Actinomyces oris、macrophage、inflammatory

Among the more than 700 known common oral bacteria, Gram-negative bacteria often serve as the main target of oral disease research, and as a PANoptosis trigger has been a hot topic of study in recent years. This study focuses on the poorly studied inflammatory response caused by Actinomycetes. Actinomyces spp. are found as resident bacteria in the human oral or plaque, also frequently act as a bridge to pathogenic bacteria that have no affinity to the tooth surface by assisting them to colonize the plaque. Actinomyces oris MG-1(A. oris), Gram-positive, was selected for this study. PMA-induced THP-1 forming macrophages were transiently co-cultured with A. oris as a model. The transient co-culture of A. oris was found to significantly enhance the release of IL-1beta into the supernatant by ELISA assay. And it was accompanied by upregulation of NLRP3, GBP-1/2 and other genes expression. Complemented by immunoblot analysis of the relevant proteins, there was a significant increase in the expression of both Caspase-1 and IL-1beta. Therefore, based on the search and study of previous published papers, we highly interest that A. oris may activate the macrophage inflammatory response through some unappreciated pathway as well, it will help to further understand the mechanism of inflammatory response.