Presence of Porphyromonas gingivalis and plasma cell dominance in gingival tissues with periodontitis.

OBJECTIVE: Porphyromonas gingivalis can invade and survive within its host epithelial cells. The aim of this study was to test our hypothesis that persistent presence of intracellular periodontal pathogens in gingival tissue causes the chronic inflammation and that an inappropriate immune response is a risk factor for periodontitis. METHODS: Together with the presence of P. gingivalis, the distribution of B cells, plasma cells, and CD4(+), CD8(+), and FOXP3(+) regulatory T cells was evaluated in gingival tissues from healthy (n = 7) and periodontitis (n = 8) sites by in situ hybridization and immunohistochemistry, respectively. RESULTS: Porphyromonas gingivalis was detected in proximity to inflammatory infiltrates in three and seven biopsies from the healthy and periodontitis sites, respectively. Compared with healthy sites, periodontal lesions contained a significantly increased number of each immune cell studied with a relative dominance of plasma cells over T cells. CONCLUSIONS: Persistent bacterial invasion of gingival tissues in combination with a plasma cell-dominant immune response may be involved in the pathogenesis of periodontitis.

Co-delivery of LETM1 and CTMP synergistically inhibits tumor growth in H-ras12V liver cancer model mice.

As hepatocellular carcinoma (HCC) is one of the most common tumors worldwide, development of novel therapeutic approaches for HCC is urgently needed. Two different genes, LETM1 and CTMP, which target mitochondrial functions, were chosen and linked using 2A-peptide sequence. Successful self-cleavage of 2A-peptide induced synergistic antitumor effect in the liver of H-ras12V, the HCC model mice, by simultaneous activation of LETM1 (Leucine zipper/EF hand-containing transmembrane-1) and CTMP (carboxyl-terminal modulator protein). Overexpression of LETM1 and CTMP significantly reduced the incidence of tumorigenesis, which were confirmed by gross and microscopic observations. Morphological changes in mitochondria, such as swelling and loss of cristae, were significant, and the prolonged activation of defects in mitochondrial function led to mitochondria-mediated apoptosis. Furthermore, with CTMP as a direct binding partner of Akt1, and LETM1 as a binding partner of CTMP, LETM1-2A-CTMP downregulated the Akt1 pathway at both Ser473 and Thr308 sites of phosphorylation. Proliferation and angiogenesis, which are important in cancer prognosis, were reduced in tumor sites after introduction of LETM1-2A-CTMP. Taken together, the results indicate that introduction of the mitochondria-targeting genes, LETM1 and CTMP, and self-processing capacity of 2A-peptide sequence exerts an antitumor effect in liver of H-ras12V mice, suggesting its potential as a tool for gene therapy.