Résumé
Objective:To construct anti-B7-H4-scFv-PE38KDEL,a recombinant toxin based on anti-B7-H4 single chain antibody (scFv),to detect anti-tumor effect of toxin protein.Methods:The anti-B7-H4-scFv gene was ligated with the toxin PE38KDEL gene by overlapping extension PCR(SOE-PCR).The recombinant gene was cloned into prokaryotic expression vector pET28a(+),and the protein was renatured and purified by chromatography (Ni-NTA),and was identified by Western blot.Indirect ELISA and flow analysis technology were used for specific identification.The inhibitory effects of toxins on tumor cells were detected by MTT assay and subcutaneous xenograft model in vitro and in vivo.HE staining and immunohistochemical analysis were performed on tumor tissues.Results:The recombinant expression vector pET28a-anti-B7-H4-scFv-PE38KDEL was obtained by restriction endonuclease di-gestion.The purified toxin protein was inoculated on the tumor cells.The tumor growth was inhibited in the tumor model.Conclusion:The recombinant toxin expression system based on anti-B7-H4 single chain antibody was successfully constructed.The recombinant toxin protein had good biological activity and anti-tumor activity.
Résumé
Glycosides are important active components in traditional Chinese medicine (TCM). Their pharmacological activity, pharmacokinetic characteristics and in vivo existence become hotspots of current studies. The metabolic pathways of these glycosides are de-glycosylation mainly mediated by gut microbiota. After glycosides were metabolized into aglycones, they could be absorbed more easily and show better pharmacological effects. In this article, we reviewed the main glycosidase in gut microbiota which helps metabolize TCM glycosides, relevant bacterial strains which generate glycosidase, as well as the de-glycosylated metabolic pathways of the representative glycosides, on the basis of gut microbiota's important roles in in vivo metabolism and efficacy of TCM glycosides. We also preliminarily solved problems in studies on de-glycosylation of TCM glycosides.