ABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of triggering receptors expressed on myeloid-1(TREM-1) in innate response to Porphyromonas gingivalis(Pg) in mice macrophages and its potential role in periodontitis development.</p><p><b>METHODS</b>Peritoneal macrophages from mice were harvested, separated and cultured, then challenged with viable Pg. Transcription and protein expression in macrophages were assessed with real time PCR and flow cytometry respectively.LP-17 peptide (10, 100 and 1000 µg/L) was utilized to block TREM-1, and tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were detected by enzyme linked absorbent analysis.</p><p><b>RESULTS</b>At 2 h after Pg challenge, transcription of TREM-1 was significantly up-regulated after Pg challenge[(7.99 ± 1.11) fold vs blank]. At 24 h after bacteria infection, increased TREM-1 expression was demonstrated by flow cytometry, with mean fluorescent intensity increasing from (7.05 ± 1.85) in blank group to (13.17 ± 2.33) in experimental group. Proinflammatory cytokine (TNF-α and IL-6) production was significantly decreased after blocking TREM-1 by LP-17 peptide(100 and 1000 µg/L).</p><p><b>CONCLUSIONS</b>TREM-1 enhanced innate immune response to Pg in macrophages, which may facilitate periodontitis development.</p>