Oral Molecular Microbiology

  • Related Key Words:
  • oral microbes
  • gut flora
  • inflammasome
  • gene expression tuning

Our projects are the effects of oral microorganisms on the gut flora, the relationship between inflammasomes and inflammatory diseases, and the regulation of gene expression in eukaryotic cells by microbial genomic fragments.

There are many bacteria in the human body that interact with the host human cells. Recently, it has been elucidated that gut bacterial flora are involved in systemic condition of human as it has been expected. We are studying the effects of oral microorganisms, especially Candida albicans, on the intestinal flora, since oral microorganisms are constantly taken up by swallowing and may affect intestinal bacteria.

Inflammasome is a trimolecular complex composed of NLR, ASC and procaspase-1 and is an intracellular sensor that conducts the production of IL-1β and IL-18, both of which are inflammatory cytokines with various biological activities. We have elucidated the mechanism of inflammasome activation by oral bacteria. Furthermore, we are analyzing the detailed mechanism of inflammasome activation using synthetic lipopeptide FSL-1 from Mycoplasma salivarium, a ligand for Toll-like receptor 2.

Regarding the regulation of eukaryotic gene expression by microbial genomic fragments, we found that they may seamlessly regulate protein expression by introducing sequences that change the secondary structure of mRNA in the 5’ untranslated region of mRNA. In fact, it has been suggested that by inserting a microbial genomic DNA fragment library into the 5’ untranslated region, the protein expression level can be controlled seamlessly from 0.5% to at least about 300%.