The role of Porphyromonas gingivalis gingipains in platelet activation and innate immune modulation

This study shows that primary features of platelet activation, i.e. changes in intracellular free calcium and aggregation, are affected by P. gingivalis and that arg‐gingipains are of great importance for the ability of the bacterium to activate platelets. P. gingivalis induced a release of the chemokine RANTES, however, to a much lower extent compared to the TLR2/1‐agonist Pam3CSK4, which evoked a time‐dependent release of the chemokine. Interestingly, the TLR2/1‐evoked response was abolished by a following addition of viable P. gingivalis wild types and gingipain mutants, showing that both Rgp and Kgp cleave the secreted chemokine. We also demonstrate that Pam3CSK4‐stimulated platelets release MIF and PAI‐1, and that also these responses were antagonized by P. gingivalis. These results supports immune‐modulatory activities of P. gingivalis and further clarify platelets as active players in innate immunity and in sensing bacterial infections, and as target cells in inflammatory reactions induced by P. gingivalis‐infection. This article is protected by copyright. All rights reserved.
Source: Oral Microbiology and Immunology - Category: Microbiology Authors: Tags: Original Article Source Type: research