IL-10 gene transfer attenuates P. gingivalis-induced inflammation

IL-10 is an anti-inflammatory cytokine secreted by stimulated Th2 lymphocytes that can downregulate inflammatory responses to bacterial challenge. We hypothesized that local delivery of IL-10 using gene-transfer will down-regulate inflammatory responses. We examined the effect of IL-10 plasmid injection on the local cytokine response. Two weeks after the implantation of chambers, either IL-10 plasmid or vector was injected into the mice. Four days later, they were challenged with an intra-chamber injection of P. gingivalis. The intra-chamber levels of IL-10, IFNγ,NFα, and IL-Iβ were evaluated after 2 and 24 hrs. The results showed that local IL-10 gene delivery elevated the levels of IL-10 at both time periods. It attenuated the levels of IFNγ (656 ± 154 to 218 ±144 pg/mL) and TNFα (23 ±2.0 to 12.5 ±2.9 ng/mL) at 2 hrs, and of IL-lβ (21.5 ± 5.7 to 12.4 ±3.0 ng/mL) at 24 hrs. The results suggest the possibility of modulating the local inflammatory response to P. gingivalis by direct IL-10 gene transfer.