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Updated: Jul 16, 2026
21:08
Engineering Cell-permeable Protein
Published on: December 28, 2009
T cell-targeted immunofusion proteins from Escherichia coli
M Better1, S L Bernhard, R E Williams
1XOMA Corporation, Santa Monica, California 90404, USA.
The Journal of Biological Chemistry
|June 23, 1995
Summary
Researchers created novel immunofusion proteins using antibodies targeting T cells and a plant toxin. These fusion proteins demonstrate potent cancer-killing capabilities, comparable to existing treatments, offering a promising therapeutic strategy.
Area of Science:
- Biotechnology
- Immunology
- Molecular Biology
Background:
- Fusion proteins combining targeting and cytotoxic domains offer therapeutic potential.
- Previous studies utilized chemical conjugates for targeted cell killing.
Purpose of the Study:
- To construct and evaluate immunofusion proteins linking H65 antibody fragments with gelonin.
- To assess the cytotoxic activity of these immunofusions against CD5-positive T cells.
Main Methods:
- Engineered immunofusion proteins using humanized Fab, F(ab')2, or single-chain variable fragments of the H65 antibody and gelonin.
- Produced and purified fusion proteins from Escherichia coli culture supernatants.
- Tested cytotoxicity against antigen-positive human cells.
Main Results:
- Developed a family of immunofusion proteins with varying cytotoxic activities (20-60 fold range).
- Identified several fusion proteins with cytotoxic potency comparable to chemical conjugates.
- Demonstrated that avidity and potency can be modulated by selecting antibody and toxin domains.
Conclusions:
- Immunofusion proteins are effective reagents for targeted cell killing.
- The design of fusion proteins allows for control over therapeutic potency.
- These findings support the development of immunofusions as a viable cancer therapy.
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