André Michel Lwoff shared the 1965 Nobel Prize in physiology or medicine with François Jacob and Jaques Monod "for their discoveries concerning genetic control of enzyme and virus synthesis," and contributing to "our knowledge of the fundamental processes in living matter which form the bases for such phenomena as adaption, reproduction, and evolution." Lwoff's fascination with microscopic life and his highly analytical mind helped identify disease production in organisms, including its genetic and metabolic mechanisms of action.
Lwoff was born in Ainay-le-Château, a tiny town in Central France, to Russian immigrants of Jewish faith--Marie Siminovitch, a sculptor, and Salomon Lwoff, a psychiatrist and chief physician at a psychiatric hospital. He often accompanied his father to different hospitals and, on one such occasion, met his father's friend, Elie Metchnikoff, who allowed the young lad to peer at a typhoid bacillus under a microscope.
As Lwoff grew older, his interest in biology grew. His father, however, wanted him to enter the more lucrative profession of medicine. At the age of seventeen, he enrolled at the Sorbonne--the University of Paris--to study medicine and biology. He spent his summers at the Marine Biology Laboratory in Roscoff, Brittany studying eye pigment in small salt or freshwater parasites. In 1921, at the age of nineteen, he began working at the Pasteur Institute in Paris. In 1925, he married microbiologist Marguérite Bourdaleix, a co-worker at the Institute. The couple collaborated extensively in their professions over many years.
Lwoff received his M.D. in 1927 and D.Sc. in 1932 from the University of Paris. Receiving a Rockefeller Foundation fellowship, he studied with Otto Meyerhof in Heidelberg. He was appointed head of a laboratory at the Pasteur Institute in 1929 and became head of Microbial Physiology 1938. In 1936, a second Rockefeller grant took him to Cambridge, England where he and his wife identified growth factor X and its inhibiting properties in the growth of the Haemophilus influenzae bacterium. He became professor of microbiology at the Science Faculty in Paris in 1959.
Lwoff's important research into microorganisms include the morphology (formation of tissue and organs) and nutritional needs of ciliates--single-celled animals covered with hair-like cilia; defining and understanding the role of growth factors, without which organisms cannot synthesize, grow, or multiply; establishing a microorganism classification system based on their energy sources and method of synthesis; and correctly classifying a bacterium genus ultimately named Moraxella lwoffii in his honor.
Almost a century earlier, in 1866, one Gregor Mendel became the first to suggest a law of inheritance in organisms, ultimately known as genetics. In the 1940s, the era of discovery of deoxyribonucleic acid (DNA) and the identification of the life cycle of bacteriophages (virus particles which infect bacterial cells), Lwoff turned his attention to the genetic properties of viruses and bacteria. It was already understood that, when virus particles entered a bacterial cell, they first remained dormant but sometimes would multiply and caused lysis (cell death). When the bacteria cell died, the bacteriophages--or lysogenic bacteria--escaped. In 1950, Jacob and Monod encouraged Lwoff to investigate this phenomenon. He placed one lysogenic bacterium in culture and watched it divide through nineteen generations of "daughter cells." Each generation was lysogenic. His amazing observation proved that lysogeny (cell death) is a genetic phenomenon.
Lwoff also discovered a difference between lysogenic (bacteriophage) and noninfectious phage particles (which he named prophages). He found that ultraviolet light would cause the harmless prophages to multiply, become destructive, and destroy cells. He, Jacob, and Monod subsequently discovered how the prophage attached to the chromosome of the infected bacterial cell--where the genes normally reside--and acted like a bacterial gene. The prophage particle cannot multiply under normal conditions; however, the trio determined that ultraviolet light and other external factors change the cell's environment, stimulating phage duplication which ultimately destroys the bacterial cell. Based on their observations, they began to wonder if viruses may cause cancer. They accurately conjectured that dormant cancer-causing properties live in the protein covering of the virus, and that certain external factors stimulate those carcinogenic qualities into life, just as prophages become lysogenic when stimulated by ultraviolet light.
In 1968, Lwoff left the Pasteur Institute to assume directorship of the Cancer Research Institute at Villejuif, a town close to Paris. He was president of the International Association of Microbiological Societies, a member of scientific academies and societies in several countries, received honors from numerous organizations, and honorary degrees from prestigious universities such as Oxford and Harvard.
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