RESUMEN
Bacterial ß-(1,3)-glucan has more advantages in terms of cost, yield and efficiency than that derived from mushrooms, plants, yeasts and fungi. We have previously developed a novel and high-yield ß-(1,3)-glucan produced by Agrobacterium sp. R259. This study aimed to elucidate the functional mechanism and therapeutic efficacy of bacterial ß-(1,3)-glucan in dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD).Mice were orally pretreated with bacterial ß-(1,3)-glucan at daily doses of 2.5 or 5mg/kg for 2 weeks. After 6 days of DSS treatment, clinical assessment of IBD severity and expression of pro-inflammatory cytokines were evaluated. In vivo cell proliferation was examined by immunohistochemistry using Ki-67 and ER-TR7 antibodies. The frequency of regulatory T cells (Tregs) was analyzed by flow cytometry. Natural killer (NK) activity and IgA level were evaluated using NK cytotoxicity assay and ELISA.The deterioration of body weight gain, colonic architecture, disease score and histological score was recovered in DSS-induced IBD mice when pretreated with bacterial ß-(1,3)-glucan. The recruitment of macrophages and the gene expression of proinflammatory cytokines, such as IL-1ß, IL-6 and IL-17A/F, were markedly decreased in the colon of ß-(1,3)-glucan-pretreated mice. ß-(1,3)-Glucan induced the recovery of Tregs in terms of their frequency in DSS-induced IBD mice. Intriguingly, ß-(1,3)-glucan reversed the functional defects of NK cells and excessive IgA production in DSS-induced IBD mice.We conclude that bacterial ß-(1,3)-glucan prevented the progression of DSS-induced IBD by recovering the reduction of Tregs, functional defect of NK cells and excessive IgA production.
Asunto(s)
Antiinflamatorios/uso terapéutico , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Linfocitos T Reguladores/inmunología , beta-Glucanos/uso terapéutico , Agrobacterium/metabolismo , Animales , Antiinflamatorios/metabolismo , Antiinflamatorios/farmacología , Proliferación Celular/efectos de los fármacos , Colon/citología , Colon/patología , Citocinas/genética , Sulfato de Dextran , Células Epiteliales/citología , Células Epiteliales/efectos de los fármacos , Heces/química , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Inmunoglobulina A/inmunología , Enfermedades Inflamatorias del Intestino/inducido químicamente , Enfermedades Inflamatorias del Intestino/inmunología , Enfermedades Inflamatorias del Intestino/patología , Células Asesinas Naturales/inmunología , Ganglios Linfáticos/citología , Masculino , Ratones Endogámicos C57BL , Proteoglicanos , Especies Reactivas de Oxígeno/inmunología , beta-Glucanos/metabolismo , beta-Glucanos/farmacologíaRESUMEN
Human colorectal cancer antigen GA733-2 fused to the immunoglobin Fc fragment (GA733-2-Fc) was expressed in stably transformed Drosophila melanogaster S2 cells, and the immunogenicity of recombinant GA733-2-Fc was investigated in mice. Recombinant GA733-2-Fc was secreted into a culture medium with a molecular mass of approximately 65 kDa. Recombinant GA733-2-Fc was purified to homogeneity using affinity fractionation with Protein A sepharose 4 Fast Flow. Recombinant GA733-2-Fc proteins elicited production of specific antibodies against recombinant GA733-2 by immunization through an intraperitoneal route. Recombinant GA733-2-Fc-induced antibodies showed a binding activity to human colorectal carcinoma HCT-116 cells. Secretory recombinant GA733-2-Fc from Drosophila S2 cell systems can be used as an effective experimental antigen for research in cancer vaccine development.