Streptococcus mutans is a gram-positive bacterium that causes tooth decay. The exopolyssacharides, mostly
glucans synthesized by the bacterium are responsible for establishing pathogenic bio-films associated with
dental caries disease. The regulatory immune and inflammatory reactions implicated by the synthesized
glucans are still not clearly understood. In this study, a water-soluble exopolyssacharide (WSP) was extracted from culture of Str. mutans. The structural properties of WSP, [α-(1 → 3, 1 → 6)-
D-glucan] were confirmed using Fourier-transform infrared spectroscopy and 13C-nuclear magnetic resonance spectroscopy. Furthermore, the effects of WSP on the global gene expression of the macrophage-like RAW 264.7 cells were analyzed using
mRNA-seq analysis. Using Gene Ontology analysis, we compiled a total of 24,421 genes that were upregulated or downregulated by more than 5.0-fold and 0.3-fold, respectively. Most of the transcripts were grouped under immune response and
inflammation-related gene categories. Among the 802 immunity-related genes analyzed,
chemokine ligand 7 (Ccl7), interleukin-1β (IL-1β), interleukin-1α (IL-1α) and
interleukin-6 (IL-6) were upregulated after WSP exposure. In addition, among a total of 344 genes related to
inflammation, Ccl7, IL-1α and
IL-6 were upregulated. These results suggest that [α-(1 → 3, 1 → 6)-
D-glucan] from Str. mutans produces activates macrophages and may contribute to the immune and inflammatory response to
periodontal disease.