Int J Oral Biol.  2018 Dec;43(4):217-222. 10.11620/IJOB.2018.43.4.217.

Effect of Various Agents on Oral Bacterial Phagocytosis in THP-1 Cells

• Song Y
• Lee HA
• Na HS
• Chung J

• KMID: 2437339
• DOI: http://doi.org/10.11620/IJOB.2018.43.4.217

Abstract

Phagocytosis is a fundamental process in which phagocytes capture and ingest foreign particles including pathogenic bacteria. Several oral pathogens have anti-phagocytic strategies, which allow them to escape from and survive in phagocytes. Impaired bacteria phagocytosis increases inflammation and contributes to inflammatory diseases. The purpose of this study is to investigate the influences of various agents on oral pathogenic phagocytosis. To determine phagocytosis, Streptococcus mutans, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were stained with 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester (CFSE), and was measured using flowcytometery and confocal microscopy. The influencing factors on phagocytosis were evaluated through the pretreatment of ROS inhibitor (N-acetyl-L-cysteine (NAC)), lysozyme, potassium chloride (KCI) and adenosine triphosphate (ATP) in THP-1 cells. Expression of pro-inflammatory cytokines was determined by enzyme-linked immunosorbent assay (ELISA). The phagocytosis of various bacteria increased in a MOI-dependent manner. Among the tested bacteria, phagocytosis of P. gingivalis showed the highest fluorescent intensity at same infection time. Among the tested inhibitors, the NAC treatment significantly inhibited phagocytosis in all tested bacteria. In addition, NAC treatment indicated a similar pattern under the confocal microscopy. Moreover, NAC treatment significantly increased the bacteria-induced secretion of IL-1β among the tested inhibitors. Taken together, we conclude that the phagocytosis occurs differently depending on each bacterium. Down-regulation by ROS production inhibited phagocytosis and lead increased of oral pathogens-associated inflammation.

Keyword

Streptococcus mutans (S. mutans); Fusobacterium nucleatum (F. nucleatum); Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans); Porphyromonas gingivalis (P. gingivalis); phagocyotosis; macrophage; monocyte

MeSH Terms

Adenosine Triphosphate
Aggregatibacter actinomycetemcomitans
Bacteria
Cytokines
Down-Regulation
Enzyme-Linked Immunosorbent Assay
Fusobacterium nucleatum
Inflammation
Macrophages
Microscopy, Confocal
Monocytes
Muramidase
Phagocytes
Phagocytosis*
Porphyromonas gingivalis
Potassium Chloride
Streptococcus mutans
United Nations
Adenosine Triphosphate
Cytokines
Muramidase
Potassium Chloride