1984 Nobel Prize in Physiology or Medicine — Jerne, Köhler, Milstein, the Immune Network Theory and Monoclonal Antibodies

What You Will Learn in This Article

You will understand why the ability to produce large quantities of a single type of antibody was such a significant discovery. It is the story of how Niels Jerne laid the conceptual groundwork with his immune network theory, and then, in 1975 in Cambridge, Georges Köhler and César Milstein achieved the breakthrough of producing monoclonal antibodies in large quantities using hybridoma technology. We will explore how this discovery became the foundation for everything from pregnancy test kits to targeted therapies like rituximab, trastuzumab, and PD-1 inhibitors, and how an Argentine-born Jewish scientist and a young German met in a Cambridge basement to change the world.

A Story Different from Common Sense — Producing Large Quantities of a Single Antibody

Our body's immune system has amazing capabilities. It can produce different types of specific antibodies against an almost infinite variety of antigens. When you receive a vaccine, antibodies specific to that pathogen are produced, and when you get a different disease, another type of specific antibody is produced. There are as many types of antibodies as there are types of antigens, and theoretically, this diversity exceeds billions.

This diversity was both a blessing and a curse. If a person wanted to obtain a specific antibody for experimental purposes, they had to purify it from the person's serum, but the serum contains a mixture of all kinds of antibodies. Isolating just one antibody that reacts with a specific antigen was virtually impossible. Experiments were only possible at the level of polyclonal antibodies — a mixture of many types, different from person to person, and with low reproducibility.

The hybridoma technology discovered by Köhler and Milstein in 1975 overturned this common sense. They fused B cells (cells that produce specific antibodies) exposed to an antigen with myeloma cells (cancer cells that proliferate indefinitely) to create hybrid cells that possess both abilities. The ability to produce a specific antibody + the ability to proliferate indefinitely in vitro = the ability to produce large quantities of the desired antibody in the desired amount.

In the language of computer science, this is a perfect example of multiple inheritance or a mixin pattern. class Hybridoma extends BCellSpecificity, MyelomaImmortality. The class inherits the target specificity method from the B cell and the indefinite self-replication method from the myeloma cell to create a new class.

The result of this combination is dramatic. It allows for the creation of standardized reagents in the laboratory, makes the mass production of clinical diagnostic tools such as pregnancy test kits possible, and later opens the door to targeted cancer therapies. Rituximab (lymphoma), trastuzumab (breast cancer HER2), adalimumab (rheumatoid arthritis), pembrolizumab (PD-1 inhibitor immune checkpoint inhibitor) — all of these are descendants of hybridoma technology.

Meanwhile, Jerne's network theory is a different kind of conceptual contribution. The theory states that antibodies not only bind to antigens but also that the surface receptors of one lymphocyte recognize and transmit signals to the receptors of other lymphocytes. In other words, the immune system is not just a simple intrusion detection system, but rather a network of self-monitoring. This theory provides a conceptual framework for understanding immune regulation, autoimmunity, and immune tolerance.

The Landscape of the Time — Macintosh and the Second Cold War Proxy War

1984 was a culturally symbolic year, coinciding with the title of George Orwell's novel and the slogan of the Macintosh advertisement.

In world history, January 24, 1984: The launch of the Apple Macintosh — the first mass-produced computer that standardized the graphical user interface and the mouse. The Super Bowl advertisement "1984" was a metaphor for rebelling against IBM's homogenized computing. The personal computer became a creative tool on the desktop, moving beyond the IBM PC (1981) and the Apple Lisa (1983).

From July to August, the Los Angeles Olympics — as a response to the United States' boycott of the Moscow Olympics four years earlier, the Soviet Union and Eastern Bloc countries boycotted. This event marked the continuation of the Cold War proxy conflict in the sports arena. Meanwhile, a significant number of Americans enjoyed kimchi stew and won considerable medals. On December 3, the Bhopal disaster in India — methyl isocyanate gas leaked from a Union Carbide pesticide plant, killing thousands immediately and tens of thousands more in the following years. This was one of the worst industrial disasters of the 20th century. On December 19, China and the United Kingdom signed the Hong Kong handover agreement, with the handover scheduled for July 1, 1997. This marked the prelude to a new international order after the Cold War.

In Korean history, May 22, 1984: The completion of the Seoul Subway Line 2 circular line — a major infrastructure project that fundamentally reshaped the urban structure of Seoul. It was part of a major transformation of public transportation in preparation for the 1988 Olympics. In November, inter-Korean economic talks began, and the issue of reuniting separated families was also brought into discussion, but it ended in failure. The Kim Il-sung-Kim Jong-il succession system was formalized, and North Korea's hereditary monarchy entered its final stages.

In this year of international political upheaval, the Nobel Committee recognized the immune system's self-regulatory network and the technology for producing large quantities of targeted antibodies. In the same year that the personal computer became a tool tailored to specific users, antibodies became capable of being mass-produced in large quantities to target specific antigens.

Niels Jerne — A Late-Blooming 40-Year-Old, the Theorist of Immunology

Niels K. Jerne (1911-1994) was a Danish immunologist. Born in London, England, to Danish parents, and having spent his childhood in various parts of Europe, he had a fluid trajectory. He began his academic career in a peculiar way, studying physics for two years at Leiden University in the Netherlands. He then returned to Denmark and worked at the National Serum Institute (1943-1955), before finally beginning to study medicine at the age of 40 and receiving his Ph.D. from the University of Copenhagen in 1951.

Despite his late start, his subsequent career was remarkable. From 1956 to 1962, he served as Director-General of the Medical Department of the World Health Organization (WHO), building a network of the world's leading immunologists. From 1962, he was a professor of microbiology at the University of Pittsburgh. In 1969, he founded the Basel Institute of Immunology with funding from Swiss pharmaceutical giant Roche and served as its director until 1980. After lecturing for one year at the Pasteur Institute in Paris in 1981, he retired.

Jerne's academic contribution was in theory. He proposed an early theory of how antibody diversity is generated through natural selection theory (1955), and his immune network theory (1974), presented in 1974, is his most important achievement in this regard.

Key points of the network theory: One type of antibody can also be recognized as an antigen by other antibodies. Antibodies have a unique three-dimensional structure called the variable region, and this structure itself is the target of recognition by another antibody with different specificity (anti-idiotypic antibody). Therefore, the immune system forms a network of antibody-antibody interactions within itself, and the balance of this network determines immune regulation.

This concept redefines the immune system as a self-referential network rather than a simple input-output system. Autoimmune diseases are understood as a state in which the balance of this network is disrupted, and immune tolerance is explained as a mechanism in which clones that recognize self-antigens are suppressed within the network. In computer science terms, this is closer to the discovery of a self-organizing network or an interaction graph.

Jerne lived as a theorist and was pleased to see his theories expanded by his successors. He humbly described his own contributions, saying that he was the one who hammered in the nails, and other scholars would drive them in.

Georges Köhler — The Nobel Prize Achievement in Just One Year in Cambridge

Georges J.F. Köhler (1946-1995) was a German immunologist. Born in Munich, he received his Ph.D. in biology from the University of Freiburg in West Germany in 1974 and then moved to the Medical Research Council (MRC) Laboratory of Molecular Biology (LMB) in Cambridge, England. His joint research with Milstein here culminated in a Nobel Prize achievement in just one year.

What makes this story remarkable is the compression of time. In just one year after the 28-year-old post-doctoral researcher arrived, he achieved a breakthrough that most people would spend their lives trying to achieve. This was possible because the hybridoma methodology was so clear, and because the combination of the two people was optimal at that moment.

In 1976, Köhler moved to the Basel Institute of Immunology, where Jerne was director, to continue his research, and in 1985, he became the director of the Max Planck Institute for Immunobiology in Freiburg. However, he died prematurely at the age of 49, in March 1995, leaving behind a 20-year research career after the hybridoma.

César Milstein — From Argentina to Cambridge

César Milstein (1927-2002) was a British biologist (born in Argentina). Born in Buenos Aires, Argentina, he studied at the University of Buenos Aires and worked at the National Institute of Microbiology in Buenos Aires from 1957 to 1960. He then obtained his Ph.D. from Cambridge University in 1960 and settled in England. From 1963 until his death in 2002, he was a research fellow at the MRC Laboratory of Molecular Biology in Cambridge and head of the Protein/Nucleic Acid Chemistry Division.

Milstein already had a background in cell fusion and antibody genetics, and when Köhler arrived, this background was ready to bear fruit. In 1975, the two successfully fused antigen-exposed B cells with myeloma cells using cell fusion techniques to create hybridomas.

These hybridoma cells possess characteristics of both parents:

• Inherited from B cells: The ability to produce specific antibodies that react with a specific antigen.
• Inherited from myeloma: The ability to proliferate indefinitely in vitro.

Result: The ability to produce large quantities of the desired specific antibodies in the desired amount. After screening the hybridomas, it is possible to obtain completely standardized antibody reagents.

After the Nobel Prize, Milstein remained in Cambridge and continued to study antibody diversity. He made ongoing contributions to the development of human antibody development and recombinant antibody technology, and continued his research at the Cambridge laboratory until his death in 2002.

CS Framework: Multiple Inheritance and API Gateway

If we reconstruct the hybridoma technology in the language of CS, we get the following diagram.

Multiple Inheritance/Mixin Pattern: A hybridoma is a child class that inherits different abilities from two parent classes. class Hybridoma extends BCell, MyelomaCell – it inherits the produceSpecificAntibody() method from the B cell and the divideForever() method from the myeloma cell. The combination of these two abilities defines the hybridoma's identity.

Standardized API Client: Polyclonal antibodies are a non-deterministic API that varies from person to person and from batch to batch. Monoclonal antibodies are a standardized SDK with precise specifications. This dramatically increases the reproducibility of experiments.

Targeted API Intercept: Rituximab (targets CD20), trastuzumab (targets HER2), pembrolizumab (targets PD-1) – these are all antibodies that bind specifically and precisely to a particular cell surface protein. By hooking only a specific endpoint of the cell surface API, it blocks signals or marks the cell.

Network Theory = Self-Referential Network: Jerne's network is a self-organizing network that maintains its state through mutual recognition between nodes. This is similar to today's web social graphs and the attention mechanisms in neural networks.

This analogy is not perfect. Cells are not discrete classes, but rather the sum of genes that are expressed probabilistically, and programming issues like the diamond problem of multiple inheritance also exist in cell fusion (stability issues after fusion). However, the concept of "combining to create new abilities" is a powerful programming principle and also a principle of cell engineering.

Academic Impact: The Dawn of Targeted Antibody Therapy

The impact of hybridoma technology, and its lineage, is now at an industrial scale.

Diagnostic Market: After the hybridoma technology, pregnancy test kits targeting hCG became widely commercialized. The same principle applies to rapid antigen tests for COVID-19 (targeting the SARS-CoV-2 spike protein). The entire medical diagnostic market is built on this technology.

Era of Targeted Therapeutics:

• 1997 Rituximab (Rituxan): The first antibody cancer drug, targeting CD20, changed the landscape of treatment for non-Hodgkin's lymphoma.
• 1998 Trastuzumab (Herceptin): Targets HER2-positive breast cancer, improving breast cancer prognosis.
• 2002 Adalimumab (Humira): Targets TNF-α, for autoimmune diseases such as rheumatoid arthritis. Became the world's best-selling drug.
• 2006 Bevacizumab (Avastin): Targets VEGF, an anti-angiogenic cancer drug.
• 2014 Pembrolizumab (Keytruda) and Nivolumab (Opdivo): PD-1 immune checkpoint inhibitors. The dawn of the era of immuno-oncology.
• 2018 CAR-T cell therapy: Combines antibody specificity with cell therapy.

Immune Regulation: Jerne's network theory subsequently provided a conceptual framework for understanding immune tolerance, autoimmune pathogenesis, and vaccine booster responses. While complete validation is difficult, its conceptual legacy is significant.

Korea's Continuation and Today

The impact of this lineage in Korea is also remarkable. Hybridoma technology was introduced in the late 1980s in the life science research laboratories of Seoul National University, Yonsei University, and KAIST. Today, Celltrion's Remsima (a biosimilar of Remicade) and Truxima (a biosimilar of Rituxan), and Samsung Biologics' large-scale CMO production are major players in the global antibody drug market. The roots of this industrial infrastructure lie in the basement of Cambridge in 1975.

In clinical practice, rituximab, trastuzumab, and pembrolizumab are standard treatments at Seoul Asan Hospital, Seoul National University Hospital, Samsung Seoul Hospital, and Yonsei Severance Hospital. A significant portion of the reason why Korea has some of the best cancer treatment outcomes in the world is due to the clinical adoption of these targeted antibodies.

Why is it Important?

What the three scientists left behind is the establishment that "naturally produced, perfect target recognition tools can be artificially mass-produced."

It is a tool that has changed all areas of diagnostics, research, and treatment. Jerne's theory redefined the immune system as a self-referential network, and the technology of Köhler and Milstein made it possible to mass-produce the components of that network.

The one-year discovery is another symbol of this award. Milstein's long-accumulated background in cell fusion and antibody genetics, combined with Köhler's young hands, resulted in a breakthrough within a year. It's a case study of how a well-prepared encounter can be so powerful.

The story of an Argentine Jewish immigrant and a young German man from Munich meeting in Cambridge symbolizes the international nature of science in the late 20th century. Just as Jerne, who created the network theory, lived a cosmopolitan life, hybridoma technology was also created through the collaboration of people of different nationalities.

After this award, the flow of antibody technology and immune regulation research continued as follows:

• 1987 Tonegawa: Genetic mechanism of antibody diversity generation (V(D)J recombination).
• 1996 Doherty and Zinkernagel: MHC-restricted cellular immunity.
• 2011 Beutler, Hoffman, and Steinman: Innate immunity and dendritic cells.
• 2018 Allison and Honjo: CTLA-4 and PD-1 immune checkpoint inhibitors.

The clinical and industrial applications of this discovery:

• Targeted antibody cancer drugs: Rituximab (1997), Trastuzumab (1998), Bevacizumab (2004).
• Immune checkpoint inhibitors: Pembrolizumab and Nivolumab (2014).
• Autoimmune antibody therapies: Adalimumab (2002), etc., among the world's best-selling drugs.
• Biosimilar industry: Celltrion and Samsung Bioepis, etc.
• CAR-T cell therapy: Kymriah (2017) and Yescarta (2017), etc.

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