Our Science: The Development of Monoclonal Antibodies
Antibodies are soluble proteins that are produced by the body in response to infections from pathogens like bacteria and viruses. Each individual antibody is synthesized by a unique cell. The secreted protein is shaped like a Y and possesses two identical yet unique binding sites that are specific for a short segment of the offending pathogen.
Vaccines capitalize on the ability of the body to produce antibodies to foreign proteins, also known as antigens, by injecting the antigen of interest with an immune stimulating molecule referred to as an adjuvant. This causes the body to react by producing antibody molecules specific for different parts of the antigen.
Once the antigen is gone from the body the antibody producing cells revert to a dormant state until the antigen is again detected in the body. Then a brisk response ensues and antibody levels rapidly rise in the bloodstream to neutralize the antigen.
Because of the genetic uniqueness among species, antibodies can also be developed that are specific for normal cell proteins. For example, immunizing a mouse with human proteins allows one to produce mouse antibodies that can recognize virtually any human antigen. This has allowed for the development of a variety of diagnostic reagents and therapeutic antibodies specific for human cells.
In the 1980s, a team of scientists won the Nobel Prize in Medicine for developing a technique that fused a common type of tumor cell with a single mouse antibody producing cell. The resulting hybrid cells all secreted the exact same antibody as the original mouse antibody producing cell and thus were called monoclonal antibodies. Since they were part tumor cell, they could be kept forever in a flask. Harvesting the fluid from these cells provided an unlimited amount of highly specific monoclonal antibodies.
Monoclonal antibodies have come to represent one of the fastest expanding opportunities in the biotechnology/pharma sector. The ability to transition from research reagents generated in mice to fully humanized structures suitable for clinical and commercial development has provided some of the most effective and largest selling therapeutics over the last 10 years.