Periodontitis-resistant and -susceptible matriline regulation of gingival transcriptome in nonhuman primates

Objective: This report identified if gingival gene expression transcriptomes demonstrated unique profiles that discriminated periodontitis-susceptible (PDS) and periodontitis-resistant (PDR) animals in health and disease. Background: Nonhuman primates generally organize their social groups based upon matriline origin. We have used a multi-generational colony of rhesus macaques to identify matrilines presenting with significant differences in periodontitis (e.g., earlier age onset, greater prevalence, and severity). Methods: Animals from 12 to 23 years of age (n = 17; 8 – PDR, 9 – PDS) were entered into a ligature-induced periodontitis trial. Gingival biopsies were taken at baseline and 0.5, 1, 3, and 5 months post-ligation, and microarray analysis was used to quantify gene expression in samples at each time point. Results: Over 1000 genes showed significant (p <.01) differences in the PDR versus PDS animals at baseline. The frequency of differences generally decreased during the disease process, and increased with resolution (i.e., 5 months). A nearly 2:1 ratio of elevated gene levels was noted in baseline PDR samples that included up-regulated MMPs, Fc receptors, chemokines, interleukins, and innate immune receptors, and down-regulated genes particularly related to epithelial biology. Most dramatically, there was a skewed differential expression of adaptive immune response genes in the PDR and epithelial cell structure/function genes in PDS samples. Conclusions: The results demonstrate substantive differences in gingival tissue response capacity/programming in PDR and PDS samples that may contribute to the differences in clinical outcomes related to the heritability of disease risk through matrilines.