title: Bacillus thuringiensis var israelensis crystal delta-endotoxin: effects on insect and mammalian cells in vitro and in vivo.
abstract: Bacillus thuringiensis var israelensis parasporal crystal delta-endotoxin was purified by ultracentrifugation on a discontinuous sucrose gradient. Native delta-endotoxin crystals showed no detectable toxicity in the vitro and in vivo systems that are described. By contrast alkali-solubilized crystal delta-endotoxin caused rapid cytological and cytopathological changes in Aedes albopictus, Choristoneura fumiferana 63 CF1, Spodoptera frugiperda and Trichoplusia ni cell lines as observed by phase-contrast microscopy and vital staining. Mouse fibroblasts, primary pig lymphocytes and three mouse epithelial carcinoma cell types showed a similar response to the alkali-soluble crystal delta-endotoxin. In addition the soluble crystal delta-endotoxin protein caused haemolysis of rat, mouse, sheep, horse and human erythrocytes. Intravenous administration of the alkali-soluble crystal delta-endotoxin to Balb. c mice at a dose rate of 15-30 micrograms of protein per gram body weight resulted in rapid paralysis followed by death within 12h. Subcutaneous inoculation of 15-30 micrograms of protein per gram body weight resulted in death of suckling mice in 2-3 h. The alkali-solubilized crystal delta-endotoxin was not toxic however, when administered per os. A comparison is made with a similar alkali-soluble fraction from the parasporal crystal delta-endotoxin of B. thuringiensis var kurstaki. With the exception of the Lepidopteran cell line, Choristoneura fumiferana 63 CF1, this soluble crystal delta-endotoxin protein showed no in vitro or in vivo toxicity, and no haemolytic activity.
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004175:Diptera; D004731:Endotoxins / Q000494:pharmacology / Q000633:toxicity*; D004912:Erythrocytes / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D007915:Lepidoptera; D051379:Mice; D008807:Mice, Inbred BALB C; D051381:Rats
chemical_list: D004731:Endotoxins