Köhler and Milstein Develop Monoclonal Antibodies

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Köhler and Milstein Develop Monoclonal Antibodies

Presentation Speech for the Nobel Prize in Physiology or Medicine, 1984

Speech

By: Hans Wigzell

Date: 1984

Source: Nobel Lectures, Physiology or Medicine 1981–1990. Singapore: World Scientific, 1993. Available online at 〈http://nobelprize.org/medicine/laureates/1984/presentation-speech.html〉 (accessed September 10, 2005).

About the Author: Hans Wigzell is a professor at the Karolinska Institute, the largest medical university in the world, and was the institute's president from 1995–2003. In 2002, Wigzell was appointed chair for the World Health Organization-United Nations AIDS Vaccine Advisory Committee.

INTRODUCTION

The ability of the immune system to recognize foreign compounds and living organisms, and to produce proteins that react with them, is one of the crucial means by which the body defends itself against disease.

The production of antibodies (proteins that react with antigens) is specific; a certain antibody forms towards a certain antigen (the foreign invader that produces an immune response in the body). In a typical immune response, however, many different kinds of antibodies will be produced, as many different antigenic targets are present.

The ability to target a single antigen can be valuable in disease therapy. Until the development of monoclonal antibodies, this ability was not clinically achievable. Monoclonal antibodies are antibodies directed towards the same antigen that are produced by the same type of cells (plasma cells). The cells are able to grow indefinitely.

Normally, this unchecked cell growth is called a myeloma, and is the root of cancer. Georges Köhler and César Milstein were successful in combining the infinite growth of myeloma cells with the exquisitely specific antibody formation ability of immune cells obtained from the spleen cells of mice.

In the scientists' pioneering research, for which they were recipients of the 1984 Nobel Prize in Physiology or Medicine, myeloma cells were fused with the antibody-secreting spleen cells of mice that had been exposed to certain antigens. The technique, called somatic cell hybridization, produced a series of combination cells called hybridomas. Each hybridoma was immortal (it could grow and divide indefinitely) and each particular hybridoma produced and secreted a particular antibody. So, each hybridoma was a factory for the production of a single (or monoclonal) antibody.

PRIMARY SOURCE

Your Majesties, Your Royal Highnesses, Ladies and Gentlemen,

It is typical for the human mind that little thought goes to the functions of our body when we are healthy, yet acute interest frequently develops in times of disease. The immune system is a somewhat anonymous, talented and well-trained cellular society within ourselves which must function properly to maintain our health. The immune defence has the inherent capacity to rapidly recognize foreign material and can subsequently remember this contact for decades, thus creating the basis for vaccination. Through a clever usage of genetic material and large numbers of cells, the immune system within a single human being is able to produce defence molecules, antibodies, in billions of different shapes. The Nobel prize winners in physiology or medicine this year have all worked with the capacity of the immune system to produce specific antibodies.

… In order to fully understand the importance of Georges Köhler's and César Milstein's discoveries we should first take some steps back. Sera from intentionally immunized animals or humans constitute very important tools in the hospitals as well as in research laboratories. They are used to diagnose infectious diseases, as well as to determine the concentration of a particular hormone in a sample. But every one of these immune sera contains a unique mixture of antibodies produced by a large number of different cells and their progeny and the various antibodies react in a similar yet distinctly different manner. Thus, each immune serum has to be tested to determine the special features of that particular serum with regard to its ability to distinguish between two related hormones, different bacteria, etc. Regardless of whether the immune serum is close to being perfect or not, it will always be used up, and it is then necessary to start again trying to produce a similar kind of serum. International standardizations of tests using immune sera have thus been greatly hampered.

The discovery and development of principles for production of the so-called monoclonal antibodies by the hybridoma technique by Georges Köhler and César Milstein have largely solved all the above major problems. And the story of the discovery of the technique also contains the moral of a saga, where the evil is put into the service of the good. How did this discovery take place? César Milstein is a highly prominent biochemist working for a long time in Cambridge in England. A major interest in his research has been to explore various facets of antibody production. Milstein used tumor cells which had arisen in cells of a type that normally produce antibodies. Such tumors also produce proteins which in all respects look like antibodies, although it is difficult to find suitable foreign structures to which they can bind. Milstein wanted amongst other things to study what would happen if two different tumor lines were allowed to fuse, e.g. what would happen to the production of the antibody-like proteins if for instance the tumor cells came from different species? Milstein constructed tumor cell lines allowing only hybrid cells between the two tumor cells to grow in certain defined tissue culture solutions. The systems worked and the hybrid cells produced large quantities of the antibody-like proteins, some of which at the molecular level could be shown to be hybrid molecules as well.

At the same time the young researcher Georges Köhler struggled in Basel in Switzerland to study normal antibody-producing cells in tissue culture. His research was in part frustrating as he could only get very few cells to survive for short periods of time. Köhler knew of the important studies of Milstein, and it seemed logical to see if normal antibody-forming cells could be fused with tumor cells to produce long-lived hybrid cell lines. If this was indeed possible the experiments of Milstein would indicate that they should then continue to produce their antibodies. At the same time the normally evil feature of tumor cells, the capacity to proliferate for ever, would now be turned into a very beneficial feature. Köhler went to Milstein's laboratory and together they wrestled with the problems and managed to solve them in a hectic two year period, 1975–1976. By that time they had succeeded to develop a technique allowing them at will to fish up exactly those rare antibody-producing cells that they wanted from a sea of cells. These cells were fused with tumor cells creating hybrid cells with eternal life and capacity to produce the very same antibody in high quantity. Köhler and Milstein called these hybrid cells hybridomas, and as all cells in a given hybridoma come from one single hybrid cell, the antibodies made are monoclonal.

Köhler's, and Milstein's development of the hybridoma technique for production of monoclonal antibodies have in less than a decade revolutionized the use of antibodies in health care and research. Rare antibodies with a tailor-made-like fit for a given structure can now be made in large quantities. The hybridoma cells can be stored in tissue banks and the very same monoclonal antibody can be used all over the world with a guarantee for eternal supply. The precision in diagnosis is greatly improved, and entirely new possibilities for therapy have been opened up via the hybridoma technique. Rare molecules present in trace amounts in complex solution can now be purified in an efficient manner using monoclonal antibodies. In all, it is therefore correct to describe the hybridoma technique discovered by Georges Köhler and César Milstein as one of the major methodological advances in medicine during this century.

Dr. Jerne, Dr. Köhler and Dr. Milstein,

On behalf of the Nobel Assembly of the Karolinska Institute I would like to congratulate you on your outstanding accomplishments and ask you to receive the Nobel Prize in Physiology or Medicine from the hands of His Majesty the King.

SIGNIFICANCE

Monoclonal antibodies have become widely used in the diagnosis and study of diseases. For example, a monoclonal antibody can be combined (tagged) with a fluorescent molecule to allow scientists to visualize the disease target when tissue samples are obtained and examined. As well, a therapeutic agent, such as a radioactive atom or an antibiotic, can be tagged to the monoclonal antibody to specifically deliver the treatment to the target.

The use of monoclonal antibodies in human applications, however, has been slower to develop, and monoclonal antibody-based drugs remain more promise than clinical reality. The major stumbling block involves rejection, as monoclonal antibodies are raised in mice, and mice antibodies are themselves recognized as foreign by the human immune system. Thus, before the beneficial monoclonal antibodies have a chance to act, they are destroyed by the human immune system.

Raising monoclonal antibodies in humans would circumvent this problem. But, ethical restrictions prevent this approach, since humans would need to be deliberately exposed to the harmful agents that are the eventual target of the therapy. Instead, laboratory-based approaches, where combinations of mouse and human antibodies are being tried, aim to make the therapeutic antibody tolerable when given to a person. Transgenic mice, which produce human antibodies against the target antigen, are a promising avenue of research.

Some examples of commercially available formulations of monoclonal antibodies include preparations to help block the host-mediated (autoimmune) rejection of organs following transplantation of pancreatic cells in type 1 diabetes mellitus, to ease the progression of rheumatoid arthritis (another autoimmune disease), to target and kill some cancer cells, and to help block allergic asthma reactions.