Project description:Investigation of whole genome gene expression level changes in Lactococcus lactis KCTC 3769T,L. raffinolactis DSM 20443T, L. plantarum DSM 20686T, L. fujiensis JSM 16395T, L. garvieae KCTC 3772T, L. piscium DSM 6634T and L. chungangensis CAU 28T . This proves that transcriptional profiling can facilitate in elucidating the genetic distance between closely related strains.
Project description:Human gingival epithelial cells (HGEp) and fibroblasts (HGF) are the main cell types of the peri-implant soft-tissue, with HGEp constantly being exposed to bacteria and HGF residing protected in the connective tissue as long as an intact mucosa-implant seal is preserved. Streptococcus oralis belongs to the commensal bacteria, is highly abundant at healthy implant sites, and might exert host modulatory effects on soft-tissue cells as described for other streptococci. Thus, we aimed to investigate the effects of S. oralis biofilm on HGEp as well as HGF. HGEp or HGF were grown on titanium separately and responded to S. oralis biofilm challenge. The cell condition of HGF was dramatically impaired after 4 hours showing a transcriptional inflammatory and stress response. In contrast, S. oralis challenge induced only transcriptional inflammatory response in HGEp with their cell condition remaining unaffected. Subsequently, HGF were susceptible compared to HGEp. The proinflammatory IL-6 was attenuated in HGF and CXCL8 in HGEp indicating a general tissue-protective role of S. oralis, forasmuch as the HGF are not exposed. In conclusion, an intact implant-mucosa interface is a prerequisite so that commensal biofilms can promote homeostasis for tissue protection.