Characterization of NODs and TLRs in innate immune response of human cementoblast cells

Abstract

Microbial Pattern-recognition receptors (PRRs), such as Toll-like receptors (TLRs) and the nucleotide-binding oligomerization domains (NODs), are essential for mammalian innate immune response. In this study, we examined the characterization of NODs and TLRs on innate immune responses in human cementoblast (HCEM) cells. The gene expression of NODs and TLRs was examined by RT-PCR. Interleukin-6 (IL-6) and Interleukin-8 (IL-8) productions in culture supernatants were measured by ELISA. Western blot analysis was performed to determine the degradation of IκB-α and Mitogen activated protein kinase (MAPK) activation in response to their agonist. The levels of NODs and TLRs were apparently expressed in HCEM cells. Although a few gene levels were weak in intact cells, the stimulation by their agonists increased the gene expression of TLRs. NODs and TLRs led to the production of IL-6 or IL-8 and the degradation of IκB-α and MAPK activation in HCEM cells. Combination treatment of NOD1 or NOD2 agonists with TLRs agonists did not influence the production of IL-6 and IL-8 in HCEM cells. Our results indicate that NODs and TLRs are functionally expressed in HCEM cells and can trigger innate immune responses. However, NOD1 and NOD2 may not be cooperated with TLRs to elicit an immune response in HCEM cells.