This model provides a better interpretation of the inflammatory process since it takes into consideration the possible synergistic effect mediated by cell interactions on cytokine secretion. The 3D co-culture model secreted higher levels of MCP-11, GRO-a, IL-6, and IL-8 and, to a lesser extent, IP-10 and G-CSF in response to A. actinomycetemcomitans LPS. All of these molecules may contribute in different ways to the progression of periodontitis. As reported by Sager et al., GRO-a Vorinostat distributor induces an intense inflammatory response when injected into mice, contributing to the degradation of the extracellular Perifosine Akt inhibitor matrix and promoting leukocyte infiltration. Kurtis et al. reported that the concentration of MCP-1 in the GCF from diseased sites is significantly higher than in the GCF from healthy sites. Moreover, IL-6 and IL-8 are important inflammatory mediators secreted by macrophages, fibroblasts, and epithelial cells and are found in high concentrations in inflamed gingival and periodontal tissues. Almasri et al. reported that gingival fibroblasts stimulated with P. gingivalis LPS secrete more GRO-a, IL-6, IL-8, and MCP-1 than unstimulated controls, which is in agreement with our results. Our results showed that 10 mM hBD-3 and 0.2 mM LL-37 alone significantly reduce the secretion of G-CSF, GRO-a, IL-6, IL-8, IP-10, and MCP-1 by the 3D co-culture model in response to LPS. In addition to the anti-inflammatory property of each peptide alone, the combination of 20 mM hBD-3 and 0.1 mM LL37 synergistically reduced the secretion of GM-SCF, GRO-a, IL6, IP-10, and MCP-1 in response to LPS. However, the combination of hBD-3 and LL-37 only had an additive effect on reducing the secretion of IL-8 at all the concentrations tested compared to the 3D co-culture model. To the best of our knowledge, no study has reported that a combination of AMPs can exert a synergistic anti-inflammatory effect. However, Semple et al. showed that the association of hBD-3 with 8bromoadenosine-cAMP, a membrane permeable cAMP analogue, reduces the secretion of TNF-a by mouse macrophages more than hBD-3 or 8Br-cAMP alone.