Bookmarkers beware: Bookmarks to pages other than the home page may not work after we change our server in April Editor's Choice | This Week in BMJ | Press releases BMJ No 7133 Volume 316 News Saturday 7 March 1998 Researchers create designer antibody Immunologists have designed an antibody that can specifically suppress just one section of the immune system, rather than having to knock out the whole system. This antibody could revolutionise the lives of people who undergo organ transplantation because the T lymphocytes that cause organ rejection could be selectively "turned off" by it, leaving the rest of the immune system intact to fight off rejection. Patients who receive bone marrow and other organs from donors run the risk of organ rejection. To prevent this happening, they are conventionally given chemotherapeutic agents, such as cyclosporin, which effectively suppresses the entire immune system. Although this means that the foreign tissue which the patients have received is not immediately rejected, it also means that they are left with few defences against invasive infections or other diseases. They are often critically immunocompromised. Now Yan Qi and Uwe Staerz from the National Jewish Medical and Research Centre in Colorado have created a hybrid antibody that will allow helper T cells to recognise a foreign organ but not allow these T cells to become activated and cause organ rejection (Nature Biotechnology 1998;16:271-6). Conventional antibody molecules have two identical arms that bind them to a specific target. This designer hybrid antibody has one binding arm, which is directed to cells on the transplanted organ and a second arm, which interferes with the activation of specific helper T cells. The result is that these T cells recognise the organ as foreign but are prevented from being activated. No other T cells are affected. The binding arm of the hybrid antibody binds to all foreign cells with a specific class II HLA type. Dr Staerz calculates that to cover virtually all donor and recipient combinations of HLA types it will be necessary to make just four or five antibodies. As a result of selective immunosuppression, he believes that 95% of all transplants will need no additional minor antigen matching. A further advantage may be conferred by administering the hybrid antibody: patients may only have to take this treatment in the short term. Dr Staerz believes that the T cells which are responsible for organ rejection may eventually be destroyed by the antibody activity, thus preventing organ rejection in the future. So far these hybrid antibodies have been shown to work in tissue culture. Dr Staerz and his colleagues will be testing them in animal models within six months, and if all goes well they expect to start clinical trials within two years. Abi Berger BMJ Home | Current issue | Past issues | Classified ads | Career Focus | Feedback Collections | About this site | About the BMJ | BMA | Medline