Mechnikov was born in a region of theRussian Empire that is today part of modern-dayUkraine to aMoldavian noble father[4] and aUkrainian-Jewish mother,[14] and later on continued his career in France. Given this complex heritage, five different nations and peoples lay claim to Metchnikoff.[15] Despite having a mother of Jewish origin, he was baptizedRussian Orthodox, although he later became anatheist.
Honoured as the "father ofinnate immunity",[16][17] Metchnikoff was the first to discover a process of immunity calledphagocytosis and the cell responsible for it, calledphagocyte, specificallymacrophage, in 1882. This discovery turned out to be the major defence mechanism in innate immunity,[18] as well as the foundation of the concept ofcell-mediated immunity, while Ehrlich established the concept ofhumoral immunity to complete the principles of immune system. Their works are regarded as the foundation of the science ofimmunology.[19]
Metchnikoff developed one of the earliest concepts inageing, and advocated the use of lactic acid bacteria (Lactobacillus) for healthy and long life. This became the concept ofprobiotics in medicine.[20] Mechnikov is also credited with coining the termgerontology in 1903, for the emerging study of aging and longevity.[21][22] In this regard, Ilya Mechnikov is called the "father of gerontology"[23][24] (although, as often happens in science, the situation is ambiguous, and the same title is sometimes applied to some other people who contributed to aging research later).
Supporters of life extension celebrate 15 May as Metchnikoff Day, and used it as a memorable date for organizing activities.[25][26]
The family name Mechnikov is a translation from Romanian, since his father was a descendant of the ChancellorYuri Stefanovi, the grandson ofNicolae Milescu Spătarul. Yuri Stefanovich immigrated to Russia together withDimitrie Cantemir in 1711 after the unsuccessful campaign ofPeter I on theDanubian Principalities. For two and a half centuries, the Mechnikov family lived in St. Petersburg, where it became connected by family ties with many Russian princely families. The word "mech" is a Russian translation of the Romanian "spadă" (sword), which originated withSpătar (Sword-bearer). His elder brotherLev became a prominent geographer and sociologist.[28]
In 1856, Metchnikoff entered the Kharkov Lycée, where he developed his interest in biology. Convinced by his mother to studynatural sciences instead of medicine, in 1862 he tried to study biology at theUniversity of Würzburg, but the German academic session would not start by the end of the year. Metchnikoff thus enrolled atKharkov Imperial University fornatural sciences, completing his four-year degree in two years.
In 1867, he returned to Russia to receive his doctorate withAlexander Kovalevsky from theUniversity of Saint Petersburg. Together they won the Karl Ernst von Baer prize for their theses on the development of germ layers in invertebrate embryos.
Metchnikoff was appointeddocent at the newly establishedImperial Novorossiya University (nowOdesa 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 toOdessa to take up the appointment of Titular Professor ofZoology andComparative Anatomy.[12][27]
In 1882 he resigned from Odessa University due to political turmoils after theassassination of Alexander II. He went toSicily to set up his private laboratory inMessina. He returned to Odessa as director of an institute set up to carry outLouis Pasteur'svaccine againstrabies; due to some difficulties, he left in 1888 and went to Paris to seek Pasteur's advice. Pasteur gave him an appointment at thePasteur Institute, where he remained for the rest of his life.[12]
Metchnikoff in his laboratory, 1913
Metchnikoff became interested in the study ofmicrobes, and especially theimmune system. At Messina he discoveredphagocytosis after experimenting on thelarvae ofstarfish. In 1882 he first demonstrated the process when he inserted smallcitrus thorns into starfish larvae, then found unusual cells surrounding the thorns. He realized that in animals which have blood, the white blood cells gather at the site of inflammation, and he hypothesised that this could be the process by which bacteria were attacked and killed by the white blood cells. He discussed his hypothesis withCarl Friedrich Wilhelm Claus, Professor of Zoology at theUniversity of Vienna, who suggested to him the term "phagocyte" for a cell which can surround and kill pathogens. He delivered his findings at Odessa University in 1883.[12]
His theory, that certainwhite blood cells could engulf and destroy harmful bodies such as bacteria, met with scepticism from leading specialists including Louis Pasteur,Emil von Behring, and others. At the time, most bacteriologists believed that white blood cells ingested pathogens and then spread them further through the body. His major supporter wasRudolf Virchow, who published his research in hisArchiv für pathologische Anatomie und Physiologie und für klinische Medicin (now called theVirchows Archiv).[27] His discovery of thesephagocytes ultimately won him the Nobel Prize in 1908.[13] He worked withÉmile Roux oncalomel (mercurous chloride) in ointment form in an attempt to prevent people from contracting thesexually transmitted diseasesyphilis.[29]
In 1887, he observed thatleukocytes isolated from the blood of various animals were attracted towards certain bacteria.[30] The first studies of leukocyte killing in the presence of specific antiserum were performed by Joseph Denys and Joseph Leclef, followed by Leon Marchand and Mennes between 1895 and 1898. Almoth E. Wright was the first to quantify this phenomenon and strongly advocated its potential therapeutic importance. The so-called resolution of the humoralist and cellularist positions by showing their respective roles in the setting of enhanced killing in the presence ofopsonins was popularized by Wright after 1903, although Metchnikoff acknowledged the stimulatory capacity of immunosensitized serum on phagotic function in the case of acquired immunity.[31]
This attraction was soon proposed to be due to soluble elements released by the bacteria[32] (see Harris[33] for a review of this area up to 1953). Some 85 years after this seminal observation, laboratory studies showed that these elements were lowmolecular weight (between 150 and 1500Dalton (unit)s) N-formylated oligopeptides, including the most prominent member of this group,N-Formylmethionine-leucyl-phenylalanine, that are made by a variety of replicatinggram positive bacteria andgram negative bacteria.[34][35][36][37] Metchnikoff's early observation, then, was the foundation for studies that defined a critical mechanism by which bacteria attract leukocytes to initiate and direct theinnate immune response of acuteinflammation to sites of host invasion bypathogens.[16][17]
Metchnikoff discovered fungal infections causing insect death in 1879 and became involved in the biological control of insect pests through his studentIsaak Krasilschik. They were able to make use ofgreen muscardine for control of insects in agricultural fields.[38][39]
Metchnikoff also self-experimented with cholera that initially supported theprobiotic notion. During the1892 cholera epidemic in France, he was surprised by the fact that the disease affected only some people but not others when they were equally exposed to the infection. To understand the differences in susceptibility to the disease, he drank a sample of cholera but never got sick. He tested on two volunteers of which one was not affected while the other almost died. He hypothesised that the difference in cholera infection was due to differences in intestinal microbes, speculating that those who have plenty of beneficial ones would be healthier.[40]
The issues of aging occupied a significant place in Metchnikoff's works.[41] Metchnikoff developed a theory thataging is caused by toxic bacteria in the gut and thatlactic acid could prolong life. He attributed the longevity of Bulgarian peasants to their yogurt consumption[42] that contained what was called the Bulgarian bacteria (now calledLactobacillus delbrueckii subsp.bulgaricus).[20] To validate his theory, he dranksour milk every day throughout his life. His scientific reasonings on the subject were written in his booksThe Nature of Man: Studies in Optimistic Philosophy (1903) and more expressively inThe Prolongation of Life: Optimistic Studies (1907).[43] He also espoused the potential life-lengthening properties of lactic acid bacteria such asLactobacillus delbrueckii subsp. bulgaricus.[44] This concept ofprobiotics, which he termed "orthobiosis,"[43] was influential in his lifetime, but became ignored until the mid-1990s when experimental evidence emerged.[20][45]
Metchnikoff won the Karl Ernst von Baer prize in 1867 with Alexander Kovalevsky on the basis of their doctoral research. He shared the Nobel Prize in Physiology or Medicine in 1908 with Paul Ehrlich . He was awarded an honorary degree by theUniversity of Cambridge in Cambridge, UK, and theCopley Medal of theRoyal Society in 1906. He was given honorary memberships of the Academy of Medicine in Paris and of the Academy of Sciences and Medicine in Saint Petersburg.[46]
Metchnikoff married his first wife, Ludmila Feodorovitch, in 1869. She died fromtuberculosis on 20 April 1873. Her death, combined with other problems, caused Metchnikoff toattempt suicide, taking a large dose ofopium. In 1875, he married his student Olga Belokopytova.[50] In 1885 Olga suffered from severetyphoid and this led to his second suicide attempt.[12] He injected himself with thespirochete ofrelapsing fever. (Olga died in 1944 in Paris fromtyphoid.)[27]
^Some sources give Metchnikoff's new-style birth date as 16 May, but this is believed by the Nobel Prize Committee to be an error stated by Metchnikoff himself in converting a nineteenth century date from old-style to new-style.[2]
^Belkin, R.I. (1964)."Commentary," in I.I. Mechnikov, Academic Collection of Works, vol. 16. Moscow: Meditsina. p. 434. Belkin, a Russian science historian, explains why Metchnikoff himself, in his Nobel autobiography – and subsequently, many other sources – mistakenly cited his date of birth as 16 May instead of 15 May. Metchnikoff made the mistake of adding 13 days to 3 May, his Old Style birthday, as was the convention in the 20th century. But since he had been born in the 19th century, only 12 days should have been added.
^Vikhanski, Luba (2016).Immunity: How Elie Metchnikoff Changed the Course of Modern Medicine. Chicago Review Press. p. 278.ISBN978-1613731109.The author cites Metchnikoff's death certificate, according to which he died on July 15, 1916 (the original is in the Archive of the Russian Academy of Sciences, Metchnikoff Fund, 584-2-208). Olga Metchnikoff did not provide a precise date for her husband's death in her book, and many sources erroneously cite it as July 16.
^ab"Élie Metchnikoff".Encyclopædia Britannica. Encyclopædia Britannica, Inc. Retrieved16 March 2015.
^Kaufmann, Stefan H E (2008). "Immunology's foundation: the 100-year anniversary of the Nobel Prize to Paul Ehrlich and Elie Metchnikoff".Nature Immunology.9 (7):705–712.doi:10.1038/ni0708-705.PMID18563076.S2CID205359637.
^Tauber, Alfred I.; Chernyak, Leon (1991).Metchnikoff and the Origins of Immunology: From Metaphor to Theory: From Metaphor to Theory. New York (US):Oxford University Press. p. 5.ISBN978-0-1953451-00.There is no clear record that he was professionally restricted in Russia because of his lineage, but he sympathized with the problem his Jewish colleagues suffered owing to Russian anti-Semitism; his personal religious commitment was to atheism, although he received strict Christian religious training at home. Metchnikoff's atheism smacked of religious fervor in the embrace of rationalism and science. We may fairly argue that Metchnikoff's religion was based on the belief that rational scientific discourse was the solution for human suffering.
Fokin, Sergei I. (2008).Russian scientists at the Naples zoological station, 1874–1934. Napoli: Giannini.ISBN978-8-8743-1404-1.
Gourko, Helena; Williamson, Donald I.; Tauber, Alfred I. (2000).The Evolutionary Biology Papers of Elie Metchnikoff. Dordrecht:Springer Netherlands.ISBN978-94-015-9381-6.
Lavrova, L N (September 1970). "[I. I. Mechnikov and the significance of his legacy for the development of Soviet science (on the 125th anniversary of his birth)]".Zh. Mikrobiol. Epidemiol. Immunobiol.47 (9).USSR:3–5.ISSN0372-9311.PMID4932822.
Schmalstieg Frank C, Goldman Armond S (2008). "Ilya Ilich Metchnikoff (1845–1915) and Paul Ehrlich (1854–1915) The centennial of the 1908 Nobel Prize in Physiology or Medicine".Journal of Medical Biography.16 (2):96–103.doi:10.1258/jmb.2008.008006.PMID18463079.S2CID25063709.
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