Related Experiment Video
Updated: Aug 12, 2026
Ex vivo Expansion of Tumor-reactive T Cells by Means of Bryostatin 1/Ionomycin and the Common Gamma Chain Cytokines Formulation
Published on: January 15, 2011
B3(Fv)-PE38KDEL, a single-chain immunotoxin that causes complete regression of a human carcinoma in mice
U Brinkmann1, L H Pai, D J FitzGerald
1Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
Abstract:
The genes encoding the heavy- and light-chain Fv regions of the monoclonal murine antibody B3, which recognizes a carbohydrate antigen on the surface of many human carcinomas, were cloned by PCR techniques and used to generate single-chain immunotoxins containing Pseudomonas exotoxin (PE). The light and heavy chains were connected by a flexible linker to form a single-chain antigen-binding protein, B3(Fv), which was in turn fused to truncated forms of PE lacking the cell-binding domain. The single-chain Fv and two different B3(Fv) immunotoxins, B3(Fv)-PE40 and B3(Fv)-PE38KDEL, were expressed in Escherichia coli and the single-chain immunotoxins were purified to near homogeneity. Both recombinant immunotoxins were shown to be cytotoxic specifically to carcinoma cell lines that express the B3 antigen on their surface; B3(Fv)-PE38KDEL was significantly more active. Furthermore, intravenous administration of B3(Fv)-PE38KDEL caused complete regression of human epidermoid carcinomas growing subcutaneously in immunodeficient mice.
