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Kinin danger signals proteolytically released by gingipain induce Fimbriae-specific IFN-gamma- and IL-17-producing T cells in mice infected intramucosally with Porphyromonas gingivalis.

Monteiro, Ana Carolina; Scovino, Aline; Raposo, Susane; Gaze, Vinicius Mussa; Cruz, Catia; Svensjö, Erik; Narciso, Marcelo Sampaio; Colombo, Ana Paula; Pesquero, João B; Feres-Filho, Eduardo; Nguyen, Ky-Anh; Sroka, Aneta; Potempa, Jan; Scharfstein, Julio.
J Immunol; 183(6): 3700-11, 2009 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19687097
Porphyromonas gingivalis, a Gram-negative bacterium that causes periodontitis, activates the kinin system via the cysteine protease R-gingipain. Using a model of buccal infection based on P. gingivalis inoculation in the anterior mandibular vestibule, we studied whether kinins released by gingipain may link mucosal inflammation to T cell-dependent immunity through the activation of bradykinin B(2) receptors (B(2)R). Our data show that P. gingivalis W83 (wild type), but not gingipain-deficient mutant or wild-type bacteria pretreated with gingipain inhibitors, elicited buccal edema and gingivitis in BALB/c or C57BL/6 mice. Studies in TLR2(-/-), B(2)R(-/-), and neutrophil-depleted C57BL/6 mice revealed that P. gingivalis induced edema through the sequential activation of TLR2/neutrophils, with the initial plasma leakage being amplified by gingipain-dependent release of vasoactive kinins from plasma-borne kininogens. We then used fimbriae (Fim) Ag as a readout to verify whether activation of the TLR2-->PMN-->B(2)R axis (where PMN is polymorphonuclear neutrophil) at early stages of mucosal infection had impact on adaptive immunity. Analyzes of T cell recall responses indicated that gingipain drives B(2)R-dependent generation of IFN-gamma-producing Fim T cells in submandibular draining lymph nodes of BALB/c and C57BL/6 mice, whereas IL-17-producing Fim T cells were generated only in BALB/c mice. In summary, our studies suggest that two virulence factors, LPS (an atypical TLR2 ligand) and gingipain, forge a trans-cellular cross-talk between TLR2 and B(2)R, thus forming an innate axis that guides the development of Fim-specific T cells in mice challenged intrabuccally by P. gingivalis. Ongoing research may clarify whether kinin-driven modulation of T cell responses may also influence the severity of chronic periodontitis.
Selo DaSilva