Biotechnology and History of Genetic Engineering

In 1980 the U.S. Supreme Court provided an important incentive for the development of biotechnology companies. In the case of Diamond v. Chakrabarty, the court ruled that biological materials may be patented. Thus, private companies could look forward to making substantial profits from therapies that they developed through genetic engineering techniques.

Among the new companies to take advantage of the court ruling was the Chiron corporation, which cloned the protein that formed the outer coat of the human hepatitis B virus. This protein, which could now be produced without the virus that it normally enclosed, provided the material for the development of the first human vaccine using recombinant DNA technology. The hepatitis vaccine has been available since 1987.

In the same year, the Food and Drug Administration (FDA) approved Genentech's drug tPA (tissue plasminogen activator). This is a human blood protein that helps to dissolve fibrin, the major protein involved in forming blood clots at the site of an injury. After the healing process is complete and clotting is no longer required at the site of the injury, the body normally releases tPA to activate an enzyme called plasmin, which dissolves fibrin. However, it was discovered that tPA could also be used as a powerful drug in the treatment of certain heart attacks. Sometimes a blood clot forms spontaneously in the body. If the clot forms or lodges in the coronary arteries of the heart, the clot blocks blood flow to the heart muscle, resulting in what is commonly called a heart attack. If tPA is given to such patients within four hours of onset, the recovery is truly remarkable. Such patients are able to leave the hospital the next day with little or no aftereffects of the heart attack. A patient not treated with tPA often remains in the hospital for a week or longer and can not resume normal activities until after a long recovery period. The drug has subsequently been approved for use with patients suffering a stroke from a blood clot in the brain with similar success.

Biotechnology has also been sucessful in development of other useful products. Today many laundry detergents contain proteases, enzymes that remove stains by digesting the protein components of the stain. However, such enzymes are inactivated by bleach. In 1988 the biotechnology company Genecor received approval for a bleach-resistant protease. This had been accomplished by isolating the gene for protease and then, using sitedirected mutagenesis, changing the gene such that the corresponding protein was no longer sensitive to inactivation by bleach.

Biotechnology has also made a great impact in agriculture. The first genetically engineered plant was patented in 1983. The first genetically engineered food was produced by a company called Calgene, in 1987. Calgene, now a part of Monsanto, produced a tomato that could be ripened on the vine and transported ripe to market. Tomatoes are normally shipped green to market and left to ripen at their destination because they are easily bruised and damaged if shipped when fully ripe. Today there is a new "green revolution" under way, in which genetically modified food will provide greater nourishment and higher yields, while simultaneously reducing the use of fertilizers and herbicides. Although there is considerable controversy surrounding these foods (sometimes referred to as "Frankenfood"), there have been no documented cases of anyone being hurt by eating them. In 1990 the biotech firm GenPharm created a transgenic dairy cow into which the genes for human milk proteins were inserted. The milk from such cows will be used for producing infant formula.