- Person
- André Lwoff
- Lived
- 1902–1994
- Field
- Microbiology
- From
- French
The story
André Lwoff was born in 1902 in Ainay-le-Château in central France into a Jewish family of Russian-Polish origin; his father was a psychiatrist and his mother an artist. He joined the Institut Pasteur in Paris at nineteen, studied single-celled organisms with Édouard Chatton, and with his wife and research partner Marguerite Lwoff showed how vitamins and growth factors work as coenzymes in microbes. During the German occupation he stayed at the Pasteur Institute and served in a Resistance network, for which he received the Medal of the Resistance.
Since the 1920s scientists had been puzzled by lysogeny: some bacterial strains carried bacteriophages, viruses that infect bacteria, without appearing to be infected, yet occasionally a few cells burst and released viruses. Many doubted that the phenomenon was real. From 1949 Lwoff watched individual bacteria under the microscope through generation after generation. He showed that they do not constantly shed virus. Instead each carries the virus in a hidden form, which he called the prophage, that is copied with the bacterium’s own genes at every division. Only when it is switched on does it multiply and kill the cell. In 1950, with Louis Siminovitch and Niels Kjeldgaard, he found that ultraviolet light switches on the prophage in nearly every bacterium in a culture, proving that its awakening is triggered from outside.
His colleagues François Jacob, Élie Wollman and Jacques Monod, working in Lwoff’s department, went on to locate the prophage on the bacterial chromosome and to discover the repressors that keep genes switched off, the foundation of the science of gene regulation. Lwoff, Jacob and Monod shared the 1965 Nobel Prize in Physiology or Medicine.
The discovery that viral genes can integrate into a host and lie dormant is central to modern medicine. HIV inserts its genes into the chromosomes of immune cells as a provirus, which is why it persists despite treatment; herpes viruses hide in nerve cells and reactivate as cold sores or shingles; and integration of certain papillomavirus genes is a step toward cervical cancer. The lysogenic phage lambda also became a basic tool of genetic engineering. Lwoff later studied poliovirus and the role of temperature in infection, directed a French cancer research institute, campaigned against the death penalty and died in 1994.
Why it matters
Lwoff’s discovery of dormant viral genes is the basis for understanding latent infections such as HIV, herpes and cancer-causing viruses, and for the science of how genes are switched on and off.
About André Lwoff
French microbiologist and Resistance member who showed how viruses hide in a cell’s genes and later awaken, key to understanding viral latency, gene control and cancer viruses. Nobel Prize 1965.
Sources
- André Lwoff, Facts NobelPrize.org
- André Lwoff, Biographical NobelPrize.org
- Award ceremony speech, 1965 NobelPrize.org
- André Michel Lwoff Wikipedia
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.