Therefore, we decided to use the median as cut-off value for high IL-6 levels

Significant Humoral Antibody Response and Disseminates Systemically Serum antibody response to periodontal pathogens is further evidence of bacterial infection. ELISA antibody analysis of serum samples from 12 MEK 162 week-infected mice showed significantly higher IgG levels in infected mice than control mice. Similarly, IgM antibody levels in 12 week-infected PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19705034 mice were significantly greater than control mice. In addition, IgG levels of 24 week-infected mice were significantly higher than controls, as were IgM levels of 24 week-infected mice than controls . To determine if bacteria spread systemically from the mouse gingival tissue, DNA was extracted from mouse heart, aorta, liver, spleen, kidney and lungs at both 12 and 24 weeks of infection, and F. nucleatum specific PCR was used to detect F. nucleatum genomic DNA. In 12-week infected mice, F. nucleatum DNA was detected in 10 out of 12 hearts, and 5 out of 6 aortas, 6 out of 12 livers, 3 out of 12 kidneys, and 7 out of 12 lungs. In 24-week infected mice, F. nucleatum genomic DNA was detected in 5 out of 12 hearts, 6 out of 6 aortas, 2 out of 12 kidneys, 1 out of 12 lungs,. These data clearly indicate that F. nucleatum spread hematogenously from gingival connective tissues to PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19706235 systemic organs. Chronic Oral Infection Induces Minimal Atherosclerotic Plaque at 24 weeks Twelve week- and 24 week-infected mice did not develop significant aortic plaque. In fact, less plaque was detected in 24 week-infected mice than 12-week-infected mice. Twenty-four week-infected mice developed minimal aortic plaque, which was 7 / 19 F. nucleatum Repression of Inflammation in ApoEnull Mice Fig 2. Chronic oral infection with F. nucleatum induced significant levels of serum F. nucleatumspecific antibodies. Graphs represent the fold-increase in F. nucleatum-specific IgG or IgM antibody titer in infected mice over control mice at both 12 and 24 weeks of infection.. doi:10.1371/journal.pone.0129795.g002 significantly smaller than sham-infected mice , while control mice developed significantly larger plaques at 24 weeks compared to 12-week controls. The intimal thickness of infected mice was significantly greater than controls at 12 weeks, while it was significantly less than controls at 24 weeks. Similar to plaque area, control mice exhibited significantly greater intimal thickness at 24 weeks than at 12 weeks. Medial thickness was unaffected by infection at either time points. The intimal/medial layer thickness ratio, which is used to normalize measurements of plaque size to variable arterial sizes, of 12-week-infected mice was significantly greater than in controls. However, as for the plaque areas, this ratio of intimal-to-medial thickness was reversed by 24 weeks, while control mice exhibited significantly greater intimal/medial ratios at 24 weeks compared to 12 weeks . These data indicate that chronic oral infection with F. nucleatum as monoinfection alone does not promote atherosclerosis induction, and may conversely inhibit plaque formation. F. nucleatum were not detected by FISH within aortic tissues of infected mice at either 12 or 24 weeks of infection. F. nucleatum genomic DNA was detected by PCR as described in the methods. N = 6. doi:10.1371/journal.pone.0129795.t002 8 / 19 F. nucleatum Repression of Inflammation in ApoEnull Mice Fig 3. Chronic oral infection results in an unexpected reduction in plaque area at 24 weeks. Infected mouse plaque area was significantly reduced when compared to sham-infected mice