Efficacy of active ingredients in Qingdai on ulcerative colitis: a network pharmacology-based evaluation.

OBJECTIVE: To elucidate the protective effect of Qingdai (, QD) on ulcerative colitis (UC) by means of and approaches. METHODS: A systems pharmacology analysis was per-formed to predict the active components of QD whereas the putative biological targets of QD against UC were obtained through target fishing, network cons-truction and enrichment analyses. Meanwhile, we examined the ameliorative effect of QD in a mouse model of dextran sulfate sodium (DSS)-induced colitis. During the 10-day experiment, the control and diseased mice were given with oral gavages of QD (1.3 g raw herbs·kg·d) or 5-aminosalicylic acid (5-ASA, 100 mg·kg·d) every day. The underlying pharma-cological mechanisms of QD in UC were determined using polymerase chain reaction tests, histological staining, enzyme-linked immunoassays, and Western blotting analysis. RESULTS: Searching from various network pharmacology databases, 29 compounds were identified in QD. According to the screening criteria suggested by TCMSP (i.e. OB ≥ 30% and DL ≥ 0.18), nine of them were considered the active ingredients that contribute to the ameliorative effects of QD on different mouse models of colitis. Most importantly, the protective effect of QD on DSS-induced colitis was significantly associated with modulations of the expression levels of glycogen synthase kinase 3-ß (Gsk3-ß) and forkhead box p3 (Foxp3), which are widely considered as important regulators of excessive inflammatory responses. CONCLUSIONS: The results of this study provide solid scientific evidence for the use of QD or its core active components in the clinical management of UC.

Disulfide-stabilized diabody antiCD19/antiCD3 exceeds its parental antibody in tumor-targeting activity.

BACKGROUND: A diabody is a bispecific antibody that is capable of recruiting a polyclonal T cell to antibody target-expressing tumor cells. However, the two chains of diabodies tend to dissociate because they are integrated non-covalently. Therefore, it is necessary to remodel the diabody to increase its stability in order to enhance the antitumor activity. METHODS: We constructed an antiCD3×antiCD19 diabody with one binding site for the T cell antigen receptor (TCRCD3) and the other for the B cell-specific antigen (CD19) by recombinant gene engineering technology. Cysteine residues were introduced into the V domains of the anti-CD3 segment. The stability and cytotoxicity of the two diabodies were compared in vitro and vivo. RESULTS: The disulfide-stabilized (ds) diabodies produced by Escherichia coli were secreted with high yields in a fully active form without a decrease in affinity. Compared with the parental diabody, the disulfide-stabilized (ds) diabody proved more stable in vitro and in vivo without reducing binding affinity. Both were able to effectively eliminate human lymphoma Raji cells by redirecting T lymphocytes in vitro and in vivo, but the ds diabody was more effective in inhibiting the growth of xenografts transplanted in BALB/C nude mice. CONCLUSION: The antiCD3×antiCD19 ds diabody is more suitable for a controlled polyclonal T cell therapy of human CD19-positive B cell malignancies than its parental diabody.