ORALS

SESSION: OxidativeMonPM1-R1	Yoshikawa International Symposium (2nd Intl. Symp. on Oxidative Stress for Sustainable Development of Human Beings)
Mon. 28 Nov. 2022 / Room: Ballroom B
Session Chairs: Fuhua YANG; Yoshiaki Harakawa; Session Monitor: TBA

14:25: [OxidativeMonPM106] OS
Enterococcus faecalis FK-23 may improve the bactericidal activity of human neutrophils via ROS production and phagocytosis
Hiroshi Ichikawa¹ ; Ryoga Higaki² ; Yukiko Minamiyama³ ; Toshikazu Yoshikawa⁴ ; ¹Major of Medical Life Systems, Graduate School of Life and Medical Sciences, Doshisha University, Kyotanabe City, Japan; ²Major of Medical Life Systems, Graduate School of Life and Medical Sciences, Doshisha University, Kyotanabe City, Kyoto, Japan; ³Kyoto Prefectural University, KYoto, Japan; ⁴Louis Pasteur Center, Kyoto, Japan;
Paper Id: 104 [Abstract]

[Purpose] Many studies have shown the importance of keeping oral health to prevent various diseases. Neutrophils (PMNs) play an important role to keep oral health by its bactericidal activity such as reactive oxygen species (ROS) production and phagocytosis. We investigated the effects of lysed and heat-treated <i>Enterococcus faecalis</i> FK-23 (LFK) on ROS production and phagocytosis of human PMNs and its mechanism. [Method] I. PMNs (1x10⁶ cells/ml) isolated from peripheral blood were stimulated with water-soluble LFK (5 mg/ml) and/or phorbol 12-myristate 13-acetate (PMA). Furthermore, the mechanism of ROS production was examined using each inhibitor. Then, ROS production was measured by MCLA-dependent chemiluminescence for a total 300s time. II. PMNs (1x10⁶ cells/ml) were incubated for 1h at 37℃ with/without LFK. Then, carboxylate-modified fluorescent beads were added to PMNs suspension and incubated for 30 min at 37℃. After that, phagocytosis was measured by flow cytometry. [Results and Conclusion] LFK transiently increased ROS production from PMNs without change in total amounts. This effect was decreased by some inhibitors of mitochondrial complex and protein kinase C (PKC) inhibitor. Thus, LFK might increase the reactivity of PMNs via PKC by enhancing mitochondrial functional ability or phagocytosis ability. These results suggest that LFK may increase bactericidal activity of PMNs to improve oral health.