Immunotoxins synthesized with the pan-T-cell monoclonal antibody T101 and ricin, acetylricin, or ricin A-chain have been compared. Native ricin was acetylated with N-acetylimidazole to block the galactose-binding site of the toxin B (binding)-chain. In the presence of lactose, both whole-ricin-containing immunotoxins were selectively cytotoxic but the ricin A-chain conjugate was less effective ...

BACKGROUND Immunotherapy is fast emerging as one of the leading modes of treatment of cancer, in combination with chemotherapy and radiation. Use of immunotoxins, proteins bearing a cell-surface receptor-specific antibody conjugated to a toxin, enhances the efficacy of cancer treatment. The toxin Abrin, isolated from the Abrus precatorius plant, is a type II ribosome inactivating protein, has a...

methods this experimental study was conducted on iranian children communities from may to november 2014. forty stool samples were obtained from laboratories and investigated for heat-labile toxin (lt). specific primers were designed and the dig -labeled pcr products were bounded to streptavidin-coated wells of a microtiter plate and detected by anti-dig-peroxidase conjugate. an internal biotin-...

Many pathogens produce the β-(1-6)-linked poly-N-acetylglucosamine (PNAG) surface polysaccharide that is being developed as a broadly protective antimicrobial vaccine. However, it is unknown whether systemically injected PNAG vaccines or antibodies would provide protective immunity against pathogens confined to the gastrointestinal tract such as Shiga toxin (Stx)-producing Escherichia coli (STE...

Evidence is presented that endocytosis is involved in the transport to the cytosol of the cytotoxin from Shigella dysenteriae 1, Shiga toxin, which acts by removal of a single adenine residue in 28-S ribosomal RNA. Inhibition of endocytosis by ATP depletion of the cells prevented toxin uptake. Exposure of HeLa S3 and Vero cells to toxin at low extracellular pH, where translocation to the cytoso...

Pokeweed antiviral protein (PAP) and ricin A chain are potent inhibitors of protein synthesis that inactivate eukaryotic 60S ribosomal subunits. Immunotoxins were prepared by linking monoclonal anti-Thy 1.1 antibodies to PAP and ricin A chain through a disulfide bond. Both the conjugates were shown earlier to specifically inhibit protein synthesis of Thy 1.1-positive target leukemic cells (AKR ...

Pokeweed antiviral protein (PAP) and ricin A chain are potent inhibitors of protein synthesis that inactivate eukaryotic 60S ribosomal subunits. Immunotoxins were prepared by linking monoclonal anti-Thy 1.1 antibodies to PAP and ricin A chain through a disulfide bond. Both the conjugates were shown earlier to specifically inhibit protein synthesis of Thy 1.1-positive target leukemic cells (AKR ...

The selective elimination of subpopulations of cells on the basis of their capacity to specifically bind various toxin conjugates has been the focus of recent intensive interest and study (1, 2). The regulatory mechanisms that control the specificity and size of discrete B lymphocyte clones occasionally break down and results in the production of deleterious antibodies directed against self det...

The distribution of alpha-bungarotoxin binding sites on chick ciliary ganglion neurons was examined at the ultrastructural level by incubating ganglia with horseradish peroxidase-conjugated toxin and examining the peroxidase-stained and thin-sectioned ganglia with the electron microscope. Both in embryonic and in adult ganglia heavy labeling was restricted to the surface membrane of short proce...