Effect of Porphyromonas gingivalis outer membrane vesicles on gingipain-mediated detachment of cultured oral epithelial cells and immune responses

2014 ◽  
Vol 16 (1) ◽  
pp. 6-16 ◽  
Author(s):  
Ryoma Nakao ◽  
Shogo Takashiba ◽  
Saori Kosono ◽  
Minoru Yoshida ◽  
Haruo Watanabe ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Immune Responses ◽  
Outer Membrane ◽  
Porphyromonas Gingivalis ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Oral Epithelial Cells ◽  
Oral Epithelial

scholarly journals Porphyromonas gingivalis Outer Membrane Vesicles Enter Human Epithelial Cells via an Endocytic Pathway and Are Sorted to Lysosomal Compartments

2009 ◽  
Vol 77 (10) ◽  
pp. 4187-4196 ◽  
Author(s):  
Nobumichi Furuta ◽  
Kayoko Tsuda ◽  
Hiroko Omori ◽  
Tamotsu Yoshimori ◽  
Fuminobu Yoshimura ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Outer Membrane ◽  
Porphyromonas Gingivalis ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Endocytic Pathway ◽  
Host Cells ◽  
Periodontal Pathogen ◽  
Dependent Manner ◽  
Human Epithelial Cells

ABSTRACT Porphyromonas gingivalis, a periodontal pathogen, secretes outer membrane vesicles (MVs) that contain major virulence factors, including major fimbriae and proteases termed gingipains, although it is not confirmed whether MVs enter host cells. In this study, we analyzed the mechanisms involved in the interactions of P. gingivalis MVs with human epithelial cells. Our results showed that MVs swiftly adhered to HeLa and immortalized human gingival epithelial cells in a fimbria-dependent manner and then entered via a lipid raft-dependent endocytic pathway. The intracellular MVs were subsequently routed to early endosome antigen 1-associated compartments and then were sorted to lysosomal compartments within 90 min, suggesting that intracellular MVs were ultimately degraded by the cellular digestive machinery. However, P. gingivalis MVs remained there for over 24 h and significantly induced acidified compartment formation after being taken up by the cellular digestive machinery. In addition, MV entry was shown to be mediated by a novel pathway for transmission of bacterial products into host cells, a Rac1-regulated pinocytic pathway that is independent of caveolin, dynamin, and clathrin. Our findings indicate that P. gingivalis MVs efficiently enter host cells via an endocytic pathway and survive within the endocyte organelles for an extended period, which provides better understanding of the role of MVs in the etiology of periodontitis.

scholarly journals Entry of Porphyromonas gingivalis Outer Membrane Vesicles into Epithelial Cells Causes Cellular Functional Impairment

2009 ◽  
Vol 77 (11) ◽  
pp. 4761-4770 ◽  
Author(s):  
Nobumichi Furuta ◽  
Hiroki Takeuchi ◽  
Atsuo Amano
Keyword(s):  
Epithelial Cells ◽  
Outer Membrane ◽  
Porphyromonas Gingivalis ◽  
Virulence Factors ◽  
Functional Impairment ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Cellular Migration ◽  
Host Cells ◽  
Periodontal Pathogen

ABSTRACT Porphyromonas gingivalis, a periodontal pathogen, secretes outer membrane vesicles (MVs) that contain major virulence factors, including proteases termed gingipains (Arg-gingipain [Rgp] and Lys-gingipain [Kgp]). We recently showed that P. gingivalis MVs swiftly enter host epithelial cells via an endocytosis pathway and are finally sorted to lytic compartments. However, it remains unknown whether MV entry impairs cellular function. Herein, we analyzed cellular functional impairment following entry of P. gingivalis into epithelial cells, including HeLa and immortalized human gingival epithelial (IHGE) cells. After being taken up by endocytic vacuoles, MVs degraded the cellular transferrin receptor (TfR) and integrin-related signaling molecules, such as paxillin and focal adhesion kinase (FAK), which resulted in depletion of intracellular transferrin and inhibition of cellular migration. Few Rgp-null MVs entered the cells, and these negligibly degraded TfR, whereas paxillin and FAK degradation was significant. In contrast, Kgp-null MVs clearly entered the cells and degraded TfR, while they scarcely degraded paxillin and FAK. In addition, both wild-type and Kgp-null MVs significantly impaired cellular migration, whereas the effect of Rgp-null MVs was limited. Our findings suggest that, following entry of P. gingivalis MVs into host cells, MV-associated gingipains degrade cellular functional molecules such as TfR and paxillin/FAK, resulting in cellular impairment, indicating that P. gingivalis MVs are potent vehicles for transmission of virulence factors into host cells and are involved in the etiology of periodontitis.

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