Noninsecticidal parasporal proteins of a Bacillus thuringiensis serovar shandongiensis isolate exhibit a preferential cytotoxicity against human leukemic T cells

Biochem Biophys Res Commun. 2000 May 27;272(1):218-23. doi: 10.1006/bbrc.2000.2765.


A Bacillus thuringiensis isolate, 89-T-34-22, belonging to the serovar shandongiensis (H22) produced noninsecticidal and nonhemolytic proteins crystallizing into irregular-shaped parasporal inclusions. The proteins showed in vitro cytotoxicity to human cells, including cancer cells, only when activated by protease treatment. The human leukemic T (MOLT-4) cells were > 100 times more susceptible than HeLa and normal T cells to the proteins of 89-T-34-22. The cytotoxicity was dose dependent and the median effective concentration for the MOLT-4 was 3.5 microg/ml. The cytopathy induced by the 89-T-34-22 proteins was characterized by remarkable condensation of the nucleus and cell-ballooning. Five major parasporal proteins of 89-T-34-22, with molecular masses in the range of 16-160 kDa, shared no similarity with the previously reported proteins in terms of the N-terminal sequence.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antineoplastic Agents / administration & dosage
  • Antineoplastic Agents / isolation & purification
  • Antineoplastic Agents / pharmacology*
  • Bacillus thuringiensis / chemistry*
  • Bacillus thuringiensis / genetics
  • Bacillus thuringiensis / ultrastructure
  • Bacterial Proteins / genetics
  • Bacterial Proteins / isolation & purification
  • Bacterial Proteins / pharmacology*
  • Cell Survival / drug effects
  • Dose-Response Relationship, Drug
  • HeLa Cells
  • Humans
  • Inclusion Bodies / chemistry
  • Leukemia, T-Cell / drug therapy*
  • Microscopy, Electron
  • Molecular Sequence Data
  • Molecular Weight
  • Spores, Bacterial / chemistry
  • Tumor Cells, Cultured


  • Antineoplastic Agents
  • Bacterial Proteins