Inflammatory immune responses by water-insoluble alpha-glucans.
Water-insoluble alpha-glucans are synthesized from sucrose by glucosyltransferase-I of mutans streptococci and play an important role in the development of dental plaque. Several types of beta-glucans in fungal cell wall components and water-soluble alpha-glucans from Streptococcus mutans are known to modulate innate immunity. In the present study, we investigated whether water-insoluble alpha-glucans also induced inflammatory innate immune responses. Our results showed that water-insoluble alpha-glucans synthesized by Streptococcus sobrinus activated mouse peritoneal exudate macrophages to produce pro-inflammatory cytokines. The immunological responses were not due to contamination by sucrose, water-soluble alpha-glucan, lipopolysaccharide, or peptidoglycan. Furthermore, human monocytes stimulated by water-insoluble alpha-glucans produced TNF-alpha and IL-8, while human polymorphonuclear cells were activated by water-insoluble alpha-glucans, resulting in chemotaxis and hydrogen peroxide production. The results demonstrated that water-soluble alpha-glucans modulate macrophage- and granulocyte-induced inflammatory immune responses, and suggest that inflammation induced by those alpha-glucans is associated with the development of periodontal diseases.
Okamoto
S
S
Department of Oral and Molecular Microbiology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita-Osaka, Japan.
Terao
Y
Y
Kaminishi
H
H
Hamada
S
S
Kawabata
S
S
D000818:Animals; D001426:Bacterial Proteins / Q000276:immunology / Q000494:pharmacology; D002460:Cell Line; D002634:Chemotaxis, Leukocyte; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D005936:Glucans / Q000276:immunology / Q000494:pharmacology*; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000187:drug effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D009000:Monocytes / Q000187:drug effects*; D018375:Neutrophil Activation; D012995:Solubility; D034363:Viridans Streptococci / Q000502:physiology
D001426:Bacterial Proteins; D016207:Cytokines; D005936:Glucans; D018836:Inflammation Mediators