title: Inhibitory effect of galectin-3 on the cytokine-inducing activity of periodontopathic Aggregatibacter actinomycetemcomitans endotoxin in splenocytes derived from mice.
abstract: Galectins, a family of animal lectins, are involved not only in development and differentiation but also in immunoregulation and host-pathogen interactions. Galectin-3 interacts with lipopolysaccharides in gram-negative bacteria such as Escherichia coli, Salmonella minnesota and Pseudomonas aeruginosa. The present study investigated whether galectin-3 inhibited the cytokine-inducing activity of periodontopathic bacterial lipopolysaccharides using splenocytes derived from mice of different ages. Lipopolysaccharides were extracted from Aggregatibacter actinomycetemcomitans Y4 and Porphyromonas gingivalis ATCC 33277, and then purified. Enzyme-linked immunosorbent assay (ELISA) analysis revealed that galectin-3 adhered to A. actinomycetemcomitans lipopolysaccharides, but not to the lipopolysaccharides of P. gingivalis. Splenocytes were prepared from 1- or 7-month-old C57BL/6 mice. Either A. actinomycetemcomitans lipopolysaccharides (200 ng mL(-1)) alone or lipopolysaccharides and murine galectin-3 (10 microg mL(-1)) were added to culture solutions, and the release of interleukin-6 (IL-6) and interferon-gamma (IFNgamma) from splenocytes was measured by ELISA after a 17-h incubation. In all mice tested, A. actinomycetemcomitans lipopolysaccharide stimulation significantly increased the production of IL-6 and IFNgamma (P<0.01). Murine galectin-3 suppressed lipopolysaccharide-induced cytokine production in the splenocytes of the 1-month-old mice (P<0.02 for IL-6; P<0.05 for IFNgamma), but not in the splenocytes of the 7-month-old mice. This suggests that responses change with age.
authors.affiliation: Laboratory of Chemistry, Tokyo Dental College, Chiba, Japan. tekato@tdc.ac.jp
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kato
authors.forename: Atsushi
authors.initials: A
authors.lastname: Uzawa
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Ishihara
mesh_terms: D000367:Age Factors; D000818:Animals; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism*; D004731:Endotoxins / Q000037:antagonists & inhibitors* / Q000276:immunology* / Q000302:isolation & purification; D037502:Galectin 3 / Q000276:immunology*; D007371:Interferon-gamma / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D015661:Pasteurellaceae / Q000737:chemistry / Q000276:immunology*; D016966:Porphyromonas gingivalis / Q000737:chemistry / Q000276:immunology; D011485:Protein Binding; D013154:Spleen / Q000166:cytology / Q000276:immunology*
chemical_list: D016207:Cytokines; D004731:Endotoxins; D037502:Galectin 3; D015850:Interleukin-6; C485095:Lgals3 protein, mouse; D007371:Interferon-gamma