Founder of immunology and serum science: Who is Jules Bordet?

(1870-1961) Belgian bacteriology scholar. He became the founder of immunology and serum science by explaining the immune reactions in blood serum. Jules-Jean-Baptiste-Vincent Bordet was born on 13 June 1870 in Soignies. In 1892, he received his medical degree from the University of Brussels and began working in Mechnikov's laboratory at the Pasteur Institute in Paris. Returning to Brussels in 1901, he was appointed director of the newly established Institute of Bacteriology and Rabies, and two years later he remained at this institution, which became the Brabant Pasteur Institute, until 1940. In the meantime, he taught at the University of Brussels as a professor of bacteriology between 1907 and 1935. Bordet, who received the 1919 Nobel Prize in Physiology and Medicine for his work that sheds light on the understanding of the immune mechanism in humans, died in Brussels on April 6, 1961.

Jules Jean Baptiste Vincent Bordet (13 June 1870 – 6 April 1961) was a Belgian immunologist and microbiologist. The bacterial genus Bordetella is named after him. The Nobel Prize in Physiology or Medicine was awarded to him in 1919 for his discoveries relating to immunity.

While working in Mechnikov's laboratory in 1895, Bordet observed that two substances were involved in bacteriolysis (the blood serum destroys bacteria by dissolving them). One of them was already known antibodies. However, when the blood serum was heated to 55°C, the antibodies, although heat stable, lost their effect on the bacteria. Starting from this, Bordet thought that a second substance should help the antibodies in bacteriolysis and that antibodies alone could not perform bacteriolysis since this heat-labile substance disappears at 55 °C. This substance, which Bordet named "alexin" and later named complement by Ehrlich, is naturally present in the blood regardless of the presence of disease-causing microorganisms. However, in order for antibodies to be produced, such a microorganism (antigen) must have entered the body. Studying the reactions between antigen-antibody-complement, Bordet announced in 1901, together with his brother-in-law, Octave Gengou, that this reaction would become a definitive diagnostic tool for infectious diseases. Indeed, when the blood of an unknown person or animal is mixed with a serum carrying the antigen of that disease, if there is an antibody in the blood, it will use the complement to destroy the antigen, so that the presence of the antibody and therefore the disease can be understood by detecting whether the complement in the blood serum has been consumed or not. The Bordet-Gengou reaction was later used in the diagnosis of infectious diseases such as typhoid fever, tuberculosis, and syphilis by Wassermann; Bordet was awarded the Nobel Prize in Physiology or Medicine in 1919 for his work that clarified the immune mechanism.

Apart from this most important work, Bordet called this phenomenon "hemolysis" in 1898, observing that not only bacteria but also foreign red blood cells (erythrocytes) entering the body were destroyed in the blood serum by the same reaction. In 1906, together with Gengou, he discovered the pertussis causative agent, Bordetella pertussis, and prepared the pertussis vaccine using the endotoxin of this airless, gram-negative bacterium.

Bordet's research, which forms the basis of immunology and serum science, has enabled the development of various vaccine and serum preparation techniques and the definitive diagnosis of many diseases.