Porphyromonas Gingivalis Interactions in Periodontal and Systemic Diseases

Porphyromonas gingivalis is recognised as a keystone pathogen in chronic periodontitis, orchestrating a shift in the subgingival microbiome towards a dysbiotic state. Its repertoire of virulence factors—including gingipain proteases, peptidyl arginine deiminase (PPAD) and outer membrane vesicles (OMVs)—enables evasion of host defences, prolongation of neutrophil survival and persistent activation of inflammasomes. Local tissue destruction is driven by sustained inflammation, osteoclast activation and impairment of periodontal ligament cell function. Beyond the oral cavity, P. gingivalis or its secreted products gain access to the circulation, where enzymatic citrullination of host proteins and modification of complement components can trigger autoimmunity and endothelial dysfunction. Epidemiological and mechanistic evidence links P. gingivalis to rheumatoid arthritis, atherosclerosis, Alzheimer’s disease and diabetes, emphasising its role in feed-forward loops of chronic inflammation and tissue damage. Understanding these interactions has guided the search for targeted inhibitors of PPAD, modulators of OMV biogenesis and vaccine candidates aimed at curbing both periodontal destruction and related systemic sequelae.

Research from Nature Portfolio

Structural biology has revealed the three-dimensional fold and catalytic mechanism of P. gingivalis PPAD, demonstrating a five-fold α/β-propeller domain that accommodates C-terminal arginine residues and discriminates against internal sites. A substrate-induced rearrangement of a “Michaelis loop” seals the active site, while a conserved cysteine-histidine-asparagine triad mediates deimination. These insights elucidate why PPAD uniquely citrullinates host proteins, offering a molecular framework for the design of selective inhibitors to disrupt the proposed link between periodontal infection and autoimmune pathologies.

Porphyromonas Gingivalis Interactions in Periodontal and Systemic Diseases publication trend

The graph below shows the total number of articles in porphyromonas gingivalis interactions in periodontal and systemic diseases across all publications each year (not limited to Nature Index journals).

Technical terms

Peptidyl arginine deiminase (PPAD): A bacterial enzyme uniquely secreted by P. gingivalis that converts C-terminal arginine residues to citrulline, implicated in autoantigen generation.

Outer membrane vesicles (OMVs): Nano-sized blebs released from the Gram-negative bacterial outer membrane carrying proteins, lipids and nucleic acids that modulate host cells.

Dysbiosis: An imbalance in the microbial community structure that contributes to disease progression.

Citrullination: A post-translational modification in which peptidyl arginine is deiminated to citrulline, altering protein charge and function.

Keystone pathogen: A low-abundance microorganism that exerts disproportionate influence on the composition and virulence of a microbial community.

References

1. Identification of a new genetic variant (G231N, E232T, N235D) of peptidylarginine deiminase from P. gingivalis in advanced periodontitis. Frontiers in Immunology (2024).
2. Porphyromonas gingivalis Peptidyl Arginine Deiminase (PPAD) in the Context of the Feed-Forward Loop of Inflammation in Periodontitis. International Journal of Molecular Sciences (2023).
3. Bacterial growth stage determines the yields, protein composition, and periodontal pathogenicity of Porphyromonas gingivalis outer membrane vesicles. Frontiers in Cellular and Infection Microbiology (2023).
4. Outer Membrane Vesicles Prime and Activate Macrophage Inflammasomes and Cytokine Secretion In Vitro and In Vivo. Frontiers in Immunology (2017).
5. Citrullination as a plausible link to periodontitis, rheumatoid arthritis, atherosclerosis and Alzheimer’s disease. Journal of Oral Microbiology (2018).
6. Structure and mechanism of a bacterial host-protein citrullinating virulence factor, Porphyromonas gingivalis peptidylarginine deiminase. Scientific Reports (2015).
7. Peptidyl Arginine Deiminase from Porphyromonas gingivalis Abolishes Anaphylatoxin C5a Activity*. Journal of Biological Chemistry (2014).