Research

Ecological DentistryOral Microbiology and Immunology

Exploring the Host-Microbe Interface to Protect Systemic Health
Our department promotes between oral microorganisms and host immunity (host-parasite interactions), aiming to protect systemic health from the oral cavity.
The oral cavity is the body’s frontline “immune interface”, constantly facing internal and external infections. Within this environment, pathogenic bacteria, commensal microbiota, and the host immune system engage is a complex interplay. We conduct basic research focused on immune responses, specifically targeting the mechanisms triggered by oral pathogenic bacteria.
A defining feature of our department is an environment that respects the individual while fostering a strong sense of collegiality. Faculty members act as coaches, drawing out students’ initiative, problem-finding skills, and creating problem-solving abilities, and supporting them closely in both education and research. Because our work is built on mutual trust, we place high value on respectful communication, teamwork, and a shared commitment to professional standards. In our graduate program, we aim to cultivate autonomous researchers with comprehensive capabilities, rather than focusing solely on experimental techniques. We welcome members from diverse backgrounds who are willing to contribute to our community and help create breakthroughs that transcend traditional disciplines.

Staff

Topics of Research

  • Immune Evasion Mechanisms and Barrier Disruption by Porphyromonas gingivalis Gingipains
  • Neutrophil Extracellular Traps (NETs) in Chronic Inflammation and Barrier Disruption
  • Innate Immune Responses Induced by Oral Pathogens
  • Impact of Periodontal Pathogens on Barrier Function Impairment
  • Pathogenic Mechanisms of Metal Allergy

Recent Publications

  1. Tsuruta, Y., Liu, T., Yokoi, H., Maruyama, K., Nemoto, E., Nishioka, T., Matsushita, K., and Tada, H.: Extracellular vesicles derived from Filifactor alocis induce interleukin-6 production in osteoblasts via Toll-like receptor 2 signaling. Archives of Oral Biology 181: 106443, 2026. doi: 10.1016/j.archoralbio.2025.106443
  2. Numazaki, K., Tada, H., Nishioka, T., Nemoto, E., Matsushita, K., Mizoguchi, I. and Sugawara, S.: Neutrophil extracellular traps inhibit osteoclastogenesis. Biochem Biophys Res Commun 705: 149743, 2024. doi: 10.1016/j.bbrc.2024.149743
  3. Tada, H., Nishioka, T., Ishiyama, R., Song, L.T., Onoue, S., Kawahara, K., Nemoto, E., Matsushita, K. and Sugawara, S.: Macrophage migration inhibitory factor-mediated mast cell extracellular traps induce inflammatory responses upon Fusobacterium nucleatum infection. Biochem Biophys Res Commun 674: 90-96, 2023. doi: 10.1016/j.bbrc.2023.06.060
  4. Tada, H., Kawahara, K., Osawa, H., Song, L.T., Numazaki, K., Kawai, J., Onoue, S., Nishioka, T., Nemoto, E., Matsushita, K. and Sugawara, S.:Hericium erinaceus ethanol extract and ergosterol exert anti-inflammatory activities by neutralizing lipopolysaccharide-induced pro-inflammatory cytokine production in human monocytes. Biochem Biophys Res Commun 636(Pt 2): 1-9, 2022. doi: 10.1016/j.bbrc.2022.10.090
  5. Endo, M., Nishioka, T., Numazaki, K., Hasegawa, H., Takahashi, T., Sugawara, S. and Tada, H.: Reactivation of p53 by RITA induces apoptosis in human oral squamous cell carcinoma cells. Anticancer Res 42(6): 2931-2937, 2022. doi: 10.21873/anticanres.15775
  6. Song, L.T., Tada, H., Nishioka, T., Nemoto, E., Imamura, T., Potempa, J., Li, CY., Matsushita, K. and Sugawara, S.:Porphyromonas gingivalis gingipains-mediated degradation of plasminogen activator inhibitor-1 leads to delayed wound healing responses in human endothelial cells. J Innate Immun 14(4): 306-319, 2022. doi: 10.1159/000519737
  7. Tada, H., Nishioka, T., Takase, A., Numazaki, K., Bando, K. and Matsushita, K.:Porphyromonas gingivalis induces the production of interleukin-31 by human mast cells, resulting in dysfunction of the gingival epithelial barrier. Cell Microbiol 21(3): e12972, 2019. doi: 10.1111/cmi.12972
  8. Ishida, N., Ishihara, Y., Ishida, K., Tada, H., Funaki-Kato, Y., Hagiwara, M., Ferdous, T., Abdullah, M., Mitani, A., Michikawa, M. and Matsushita, K.: Periodontitis induced by bacterial infection exacerbates features of Alzheimer's disease in transgenic mice. NPJ Aging Mech Dis 3: 15, 2017.doi: 10.1038/s41514-017-0015-x
  9. Tada, H., Matsuyama, T., Nishioka, T., Hagiwara, M., Kiyoura, Y., Shimauchi, H. and Matsushita, K.:Porphyromonas gingivalis gingipain-dependently enhances IL-33 production in human gingival epithelial cells. PLoS One 11(4): e0152794, 2016. doi: 10.1371/journal.pone.0152794

Laboratory Contacts

Prof. Hiroyuki Tada

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Research