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Microbiology => Genetic Engineering => Interferon
Interferon
Interferon, any of a group of antiviral proteins produced by animals, including humans, in response to infection by viruses. First recognized in chick embryo cells by British virologist Alick Isaacs and his Swiss colleague Jean Lindenmann in 1957, interferons were found to block further viral infection of body cells. The active antiviral substance is not the interferons themselves, but proteins that interferons cause other cells to produce. Some of these proteins have been identified, but their manner of operation is not yet well understood. It is clear, however, that interferons play a role in the body's most important defenses against viruses, and that they help fight bacteria and other disease-causing agents.
Interferons may be grouped into three categories. Alpha (leukocyte) interferons are made by white blood cells, beta (fibroblast) interferons by skin cells, and gamma (immune) interferons by lymphocytes after stimulation by antigens.
During the 1960s physicians attempted to use interferons to treat virus-caused human diseases, especially colds, but the therapy was determined impractical due to the enormous cost of obtaining minute quantities of interferons from human white blood cells. Researchers then tried to stimulate the body to make its own interferons with inducers such as synthetic nucleic acids. These chemicals worked, but the body quickly became tolerant of them, and they lost their effect. In 1980, however, interferons were made available in sufficient quantities through genetic engineering techniques, and trials testing dosage levels and side effects were begun the following year.
Thus far only some alpha interferons have been tested, but they have shown promise against a host of viral diseases. The use of interferons against such cancers as malignant melanoma and renal cell cancer has produced mixed results. The side effects accompanying interferons can range from mild to life-threatening. Beta and gamma interferons have not yet been tested in quantity, but may prove more useful than alpha interferons.
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