monoclonal antibody

César Milstein, a molecular biologist and winner of the 1984 Nobel Prize for Physiology or Medicine. This photograph was taken in the Medical Research Council Laboratory of Molecular Biology, Cambridge, where Milstein and his colleagues developed monoclonal antibodies, the achievement for which his Nobel Prize was awarded.

Monoclonal antibody production. Antibodies are collected from a mouse after immunization and are fused with tumour cells grown in tissue culture to form antibody hybridomas. These are cloned to give large numbers from which the antibodies can be harvested.

Antibody produced by fusing an antibody-producing lymphocyte (white blood cell) with a cancerous myeloma (bone-marrow) cell. The resulting fused cell, called a hybridoma, is immortal and can be used to produce large quantities of a single, specific antibody. By choosing antibodies that are directed against antigens found on cancer cells, and combining them with cytotoxic drugs, it is hoped to make so-called magic bullets that will be able to pick out and kill cancers.

It is the antigens on the outer cell walls of germs entering the body that provoke the production of antibodies as a first line of defence against disease. Antibodies ‘recognize’ these foreign antigens, and, in locking on to them, cause the release of chemical signals in the bloodstream to alert the immune system for further action. MABs are copies of these natural antibodies, with the same ability to recognize specific antigens. Introduced into the body, they can be targeted at disease sites.

The full potential of these biological missiles, developed by César Milstein and others at Cambridge University, England, in 1975, is still under investigation. However, they are already in use in blood-grouping, in pinpointing viruses and other sources of disease, in tracing cancer sites, and in developing vaccines.