Role of OmpA2 surface regions ofPorphyromonas gingivalisin host-pathogen interactions with oral epithelial cells

Abstract

Outer membrane protein A (OmpA) is a key outer membrane protein found in Gram‐negative bacteria that contributes to several crucial processes in bacterial virulence. In Porphyromonas gingivalis, OmpA is predicted as a heterotrimer of OmpA1 and OmpA2 subunits encoded by adjacent genes. Here we describe the role of OmpA and its individual subunits in the interaction of P. gingivalis with oral cells. Using knockout mutagenesis, we show that OmpA2 plays a significant role in biofilm formation and interaction with human epithelial cells. We used protein structure prediction software to identify extracellular loops of OmpA2, and determined these are involved in interactions with epithelial cells as evidenced by inhibition of adherence and invasion of P. gingivalis by synthetic extracellular loop peptides and the ability of the peptides to mediate interaction of latex beads with human cells. In particular, we observe that OmpA2‐loop 4 plays an important role in the interaction with host cells. These data demonstrate for the first time the important role of P. gingivalis OmpA2 extracellular loops in interaction with epithelial cells, which may help design novel peptide‐based antimicrobial therapies for periodontal disease.

Inhibition of sialidase activity and cellular invasion by the bacterial vaginosis pathogen Gardnerella vaginalis

“…We performed invasion assays at an MOI of 1:100, and observed association and invasion rates of approximately 1%; typical of invasion rates our laboratory commonly observes for oral anaerobes such as Porphyromonas gingivalis, Tannerella forsythia , and Fusobacterium spp. (Naylor et al 2017). In contrast, assays performed in the presence of Zanamivir, displayed a dramatic, and statistically significant reduction in levels of total association (2.2-fold, p  = 0.03), adhesion (1.95-fold, p  = 0.04), and invasion (2.4-fold, p  = 0.03) (Fig.…”

“…Invasion assays were performed as previously described (Naylor et al 2017). In brief, 2.0 × 10 5 HeLa cells were seeded in 24-well tissue-culture plates overnight in media without pen/strep, before washing with PBS and incubated for 1 h at 37 °C, 5% CO 2 in DMEM with 2% bovine serum albumin (BSA) (Sigma, Poole).…”

The characteristics of antibiotic resistance and phenotypes in 29 outer‐membrane protein mutant strains in Aeromonas hydrophila

“…Meanwhile, ΔAHA_1280 also increased the haemolytic activity in this study. The previous research reported that ΔompA2 in Porphyromonas gingivalis shows a reduction in biofilm formation higher than that of ΔompA1 and it plays a significant role interacting with human epithelial cells, which further supports our finding about the distinct biological functions among these OmpA family proteins (Naylor et al ., ). We previously reported that A0KHS0 ( AHA_1280 ) and A0KHS1 ( AHA_1281 ) have several lysine succinylation modifications sites but not A0KHR9 ( AHA_1279 ).…”

Effects of the periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia on platelets

“…No significant differences were observed between either the ΔompA1 or the ΔompA2 deficient mutants when compared to the parent strain within CHRF-288-11 association as determined by antibiotic protection assays and flow cytometry. It has previously been shown that OMPA, specifically the OMPA2 subunit is fundamental for interactions between P. gingivalis and epithelial cells in vitro (Naylor et al, 2016). However the data produced within this chapter of work suggests that P. gingivalis interactions with CHRF-288-11 cells occur independently of either OMPA subunit, suggesting that both of the OMPA subunits can facilitate bacterial association with CHRF-288-11 cells independently.…”

“…Recently, the OmpA protein, specifically the A2 subunit, has been shown to contribute to both biofilm formation and host-cell interactions with epithelial cells (Naylor et al, 2016), with the ompA genes being upregulated in highly invasive populations of P.…”