Genetic engineering, sometimes known as genetic modification, is the process of manipulating DNA to produce desired outcomes. Scientists do this to modify or enhance an organism’s characteristics by promoting specific traits. In this article, we explore a few groundbreaking ways that experts use genetic engineering in the field of health care, in order to create vaccines, medications, and other potentially life-saving treatments.
1. Genetically engineered insulin
Insulin is a protein hormone produced by the pancreas. It is intrinsic to the body’s ability to regulate blood sugar levels.
Insulin triggers cells throughout the body to absorb glucose (sugar) from the bloodstream, keeping blood sugar levels within a healthy range. When the body produces insufficient amounts of insulin, or when the body does not respond properly to insulin, diabetes can occur. According to the World Health Organization, 422 million adults around the world have diabetes.
To treat diabetes, some patients receive injections of insulin. Until relatively recently, scientists sourced medical insulin from cattle and pigs. Because cows and pigs are genetically different from humans, these forms of insulin contain slightly different amino acids from the insulin produced by the human body. As a result, some diabetics had adverse reactions following the administration of animal-derived insulin. This problem was overcome by genetic engineering, which has enabled the production of insulin in a purer form and eliminated the trace impurities that caused adverse reactions.
2. Genetically engineered antivenom
In 2006, studies at the Liverpool School of Tropical Medicine in the UK led to pivotal advancements in the production of genetically engineered antivenom. (An antivenom is a type of medication used to counteract venomous animal bites and stings.)
Prior to this development, manufacturers produced antivenom by administering a small amount of venom to large animals, then extracting antibodies from the animals’ blood. Scientists involved in the study in Liverpool discovered that they could generate antibodies using synthetic DNA that closely resembles the most toxic parts of the actual venom.
The team, led by Dr. Simon Wagstaff, targeted the carpet viper, a venomous West African snake responsible for a large number of human fatalities. Many people bitten by the carpet viper die from hemorrhaging caused by a protein in the snake’s venom that destroys human blood vessels. Wagstaff and his colleagues managed to isolate the parts of the genes that generate this protein from the snake’s venom gland. The team identified seven key elements they deemed the most clinically important, synthesizing them into a single string of DNA to be used as an immunization. Those immunized with the synthetic DNA produced antibodies that reacted with the hemorrhage-causing toxins from the snake venom.
3. Genetically engineered vaccines
Hepatitis B is a viral liver disease. Early vaccines against hepatitis B consisted of virus fragments isolated from the blood of people infected with the disease. When introduced to a healthy human body, these disease fragments provoked an immune response. If the individual subsequently contracted the hepatitis B virus, their immune system would recall these gene fragments, recognize the disease, and rapidly eliminate it before infection took hold.
Obtaining antivirals from a diseased individual and introducing them to a healthy human body is less than ideal. Despite purification procedures, the vaccine sometimes contained a complete, infectious form of the virus—meaning that those who received the vaccine sometimes developed the disease it was supposed to prevent. In addition, using infected individuals as a vaccine source presents practical and ethical issues.
Today, manufacturers produce the hepatitis B vaccine using Saccharomyces cerevisiae, a type of yeast. A gene that produces parts of the hepatitis B virus is introduced to the yeast, which then generates fragments of the virus. The virus fragments are extracted and purified for use as a vaccine. Genetic engineering effectively removes the whole virus from the vaccine-making process, eliminating the risk of contamination.
4. Genetically engineered blood products
Researchers at Carnegie Mellon University in Pennsylvania created artificial hemoglobin through genetic engineering techniques. Scientists hope that the breakthrough could lead to the development of viable synthetic blood products, alleviating the problem of blood bank shortages and potentially saving millions of lives.
Hemoglobin is vital to the delivery of life-giving oxygen to tissue and organs throughout the body. Chien Ho, lead researcher at Carnegie Mellon University, told Science Daily he was very excited about the discovery, explaining that the genetically engineered substance showed great potential as a successful oxygen carrier suitable for human use.
Given current blood shortages, the ability to produce artificial blood has huge ramifications—not only in terms of individual outcomes, but in lifting the burden on struggling health systems. Chien Ho pointed out that as the US population ages, demand for blood products will increase, for use in transfusions, surgeries, and the treatment of blood disorders. The demand for a viable blood substitute is becoming increasingly urgent.
The American Association of Blood Banks receives over 13 million units of blood per year, but with 36,000 units of red blood cells needed in American hospitals and ERs every day, demand is outstripping supply. Several research programs are currently aimed at developing artificial blood. However, scientists will need to conduct a great deal of testing and research to prove the safety and effectiveness of artificial blood products before receiving FDA approval. The incorporation of synthetic blood products into mainstream medicine is not likely to happen overnight. Nevertheless, scientists and medical practitioners the world over recognize the potential of artificial blood products to revolutionize medicine.