Monoclonal Antibodies

Abstract From the time that Kohler and Milstein first published their technique of using a hybridoma to produce monoclonal antibodies (Mabs), a major and rapid progression occurred in the field of medicine, specifically immunology. Mabs began to be used as tools for diagnosing and treating disease and have proven to be valuable agents in the research laboratory. When tagged with fluorescent dyes, radioactive or heavy atoms (gold), enzymes or toxins, they help identify molecules of biological and medical importance. They can be used with microscopic techniques to identify structures or molecules within a cell. Mabs are being tested experimentally to inhibit transplant rejection, to alleviate and suppress autoimmune disease, and to detect and treat cancer. For example, Mabs can be used to remove undesirable lymphocytes from donor bone marrow cells prior to transplantation to avoid Graft versus Host disease. However, the use of Mabs produced by the mouse hybridoma can interfere with the effectiveness of the antibodies or cause allergic reactions in humans. Thus, new strategies are being explored for the construction of Mabs that can better penetrate the target tissue and are not recognized as foreign by the human immune system. Among these approaches is the cloning of human antibodies, or the placing of human antibody genes into the genome of mice that have been bred without an antibody‐producing mechanism of their own. Mabs are being used in both the diagnosis and treatment of cancer because many of the same cancer types present in different patients were shown to have similar cell surface molecules. Mabs, tagged with chemotherapeutic agents or radioactive atoms, when targeted to these tumor antigens, have the potential to destroy tumor cells. Studies are being conducted to evaluate the effectiveness of Mabs to block growth factors or receptors on tumor cells; to target specific tissue components of the tumor or its blood vessels; to interfere with cell signals; or with apoptosis (programmed cell death). When labeled with radioactive isotopes, Mabs can also be used in the diagnosis of disease in nuclear medicine procedures. They are being used in the food industry to identify either contaminating molecules, or the presence of harmful bacteria. They are also being used to create strategic reserves of vaccines and antibodies for infectious agents that could be used in biowarfare.