Élie Metchnikoff: Immune System Pioneer

Élie Metchnikoff

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Élie Metchnikoff was born in Ukraine in 1845 and later became a naturalized French citizen. He was a Ukrainian scientist considered the “father of innate immunity.” In 1908, he won the Nobel Prize in Physiology or Medicine for his work on phagocytosis and cellular immunity. His research laid the foundation for our understanding of how the immune system works. Metchnikoff died in 1916 at the age of 71. His legacy continues to influence immunology research to this day.

Élie Metchnikoff: Early Life in Ukraine

Élie Metchnikoff

Élie Metchnikoff (Ilya Ilyich Mechnikov – Илья Ильич Мечников) was born on May 15th, 1845 in Kharkiv Oblast, Ukraine. He was the youngest of five children. His father (Ilya Mechnikov) was an officer in the Russian Imperial Guard. His mother (Emilia Lvovna) was the daughter of the writer Leo Nevakhovich and home-schooled Élie until the age of 10.

Élie enrolled in the Kharkiv Lycee in 1856 with plans to pursue medicine as a career. His mother convinced him to study natural sciences. In 1862, Élie enrolled in the Kharkiv Imperial University (now V.N. Karazin Kharkiv National University), where he completed his four-year degree in two years. 

Advanced Studies and Research

Élie Metchnikoff

In 1864, Élie traveled to Germany to study marine fauna on the small North Sea island of Heligoland. He was advised by the botanist Ferdinand Cohn to work with Rudolf Leuckart at the University of Giessen. It was in Leuckart’s laboratory that Élie made his first scientific discovery of alternation of generations (sexual and asexual) in nematodes. In 1865, while at Giessen, Élie discovered intracellular digestion in flatworms, and this study influenced his later works. Moving to Naples the next year he worked on a doctoral thesis on the embryonic development of the cuttlefish Sepiola and the crustacean Nebalia. A cholera epidemic in the autumn of 1865 made him move to the University of Göttingen, where he worked briefly with W. M. Keferstein and Jakob Henle.

Metchnikoff returned to Russia in 1867 to complete his Ph.D. at the University of St. Petersburg. Together with Alexander Kovalevsky, he won the Karl Ernst von Baer prize for his work on germ layer development within invertebrate embryos.

Metchnikoff was appointed docent at the newly established Imperial Novorossiya University (now Odessa University). Only twenty-two years of age, he was younger than his students. After being involved in a conflict with a senior colleague over attending scientific meetings, he transferred to the University of Saint Petersburg in 1868, where he experienced a worse professional environment.

In 1870 he returned to Odessa to take up the appointment of Titular Professor of Zoology and Comparative Anatomy.

In 1882 Élie Metchnikoff resigned from Odessa University due to political turmoil after the assassination of Alexander II. He went to Sicily to set up his private laboratory in Messina. He returned to Odessa as director of an institute set up to carry out Louis Pasteur’s vaccine against rabies; due to some difficulties, he left in 1888 and went to Paris to seek Pasteur’s advice. Pasteur gave him an appointment at the Pasteur Institute, where he remained for the rest of his life.

Aging and Immune System Research

Élie Metchnikoff

Metchnikoff’s major contribution to biology is his discovery of phagocytosis. Phagocytosis is the process by which cells engulf and destroy bacteria and other foreign particles. Metchnikoff observed that certain cells in the body were able to destroy bacteria and other unwanted organisms. He theorized that these cells, called “phagocytes,” were responsible for the body’s immunity to disease.

Aging occupied a significant place in Metchnikoff’s works. Metchnikoff developed a theory that aging is caused by toxic bacteria in the gut. He further theorized that lactic acid could prolong life. He stated his belief that the longevity of Bulgarian peasants was attributed to their regular consumption of yogurt. Based on this theory, Metchnikoff drank sour milk every day. Metchnikoff’s theories on probiotics were largely ignored until the mid-1990s, when experiments produced evidence supporting his early work.


Élie Metchnikoff

Metchnikoff was elected to the French Academy of Sciences in 1903 and awarded the Nobel Prize in Physiology or Medicine in 1908 “in recognition of his work on immunity.” On July 15, 1916, he died at his country home in Étables-Sur-Mer, France.

The Élie Metchnikoff Prize “for contributions to the field of immunology” was established in his honor by the International Union of Immunological Societies. Élie Metchnikoff is commemorated on a postage stamp issued by Bulgaria’s postal service. A street in Kharkiv, Ukraine, where he was born, is named after him.