Renato Dulbecco Biography (1914-)
Renato Dulbecco was a pioneer in the field of virology, the study of viruses.Dulbecco developed the plaque assay technique which allowed scientists to quantify the number of viral units in a laboratory culture, thus making possible most of the later major discoveries in virology. For his work in the studyof viruses that could cause cancer in animals and humans, Dulbecco shared the1975 Nobel Prize in medicine or physiology with microbiologist David Baltimore and oncologist Howard Temin.
Dulbecco was born in Catanzaro, Italy, on February 22, 1914, the son of Leonardo Dulbecco, a civil engineer, and Maria Virdia Dulbecco. During World War Ihe lived with his mother and siblings in Turin and Cuneo after his father was called into military service. After the war, the family relocated to Imperia, where Dulbecco received his primary and secondary education. His interestin physics led him to build an electronic seismograph, one of the earliest ofits kind. He entered the University of Turin in 1930 at the age of 16 to study medicine. By the end of his first year of study, his interests turned to biology and he went to work as a laboratory assistant for Giuseppe Levi, a professor of anatomy and an expert on nerve tissue, where he learned histology and the techniques of cell culture. His fellow students included microbiologist Salvador Edward Luria and neurologist Rita Levi-Montalcini, both of whom were to be Nobel Prize winners and were to influence Dulbecco's scientific career.
Dulbecco received his doctorate of medicine in 1936 and was drafted into theItalian army as a physician. He was discharged in 1938 but was recalled in 1939 at the outset of World War II. After Italy, led by dictator Benito Mussolini, became a belligerent in 1940, Dulbecco served in France and then in Russia. A serious wound in Russia in 1942 hospitalized him for several months, after which he went home. Following the fall of Mussolini's government, Dulbeccowent into hiding in a small village near Turin and became a physician to thelocal partisan units resisting the German occupation. After the end of the war in 1945, he was elected a city councilor of Turin but soon gave up the position to return to scientific study and research at the University of Turin.In 1946 Luria invited Dulbecco to join his research group at the University of Indiana at Bloomington. Dulbecco and Levi-Montalcini both immigrated to theUnited States the following year. He became an American citizen in 1953.
At Indiana, Dulbecco experimented with bacteriophage, viruses that invade andkill bacteria cells. His principal discovery at this time was that bacteriophage previously rendered inactive by exposure to ultraviolet light could be reactivated by exposure to white light of short wavelength. This work attracted the attention of Max Delbrück, a German-born physicist-turned-microbiologist. In 1949, Delbrück invited Dulbecco to join him at the CaliforniaInstitute of Technology (Caltech) in Pasadena. Dulbecco became a research fellow and later a professor of biology at Caltech, where he remained until 1963.
In the early 1950s, Dulbecco developed a method for determining the number ofunits of a given virus in a culture of animal cell tissue. This method, called the plaque assay technique, enabled the researcher to count the viral units in a culture by examining the number of plaques, or clear spots, in the culture, where the viruses had killed the host cells. This method was the basisfor many of the later important advances made in animal virology. One spectacular practical result of the use of the plaque assay technique was the development of physician Albert Sabin' s polio vaccine, developed from a living virus, used to prevent poliomyelitis, a paralyzing and sometimes lethal disease.This vaccine eventually superseded the vaccine produced earlier by physicianJonas Salk, which was made with a virus killed by formaldehyde.
In the late 1950s Dulbecco's interest shifted to the study of animal virusesthat could cause cancerous tumors. His research over the next 20 years was devoted to an investigation of the precise manner in which particular viruses could transform host cells in such ways that the cell was either killed or multiplied indefinitely (that is, became cancerous). While working on the polyoma virus, which causes tumors in mice, Dulbecco and his colleagues discoveredthat the virus's DNA (deoxyribonucleic acid) combined with the DNA of the host cell and remained there as a provirus (a virus that is integrated with a cell's genetic material and that can be transmitted without causing disintegration when the cell reproduces) which controlled the genetic mechanism of the cell. In a process called cell transformation, the virus could induce a cancer-like state, causing the cell to multiply endlessly in a tissue culture environment in the laboratory. In an animal body, the same process of celltransformation and subsequent cell multiplication led to the growth of cancerous tumors.
In 1963 Dulbecco left Caltech to become one of the original fellows of the Salk Institute, a research organization founded by Salk in La Jolla, California. There Dulbecco continued his research on animal tumor viruses.
In 1972 Dulbecco moved to London to become assistant (later deputy) directorof research at the Imperial Cancer Research Fund. He was by then involved inthe study of breast cancer in human beings. While in London, Dulbecco, Baltimore, and Temin were jointly awarded the Nobel Prize in medicine or physiologyfor their work on tumor virology. In his Nobel Prize lecture Dulbecco made astrong plea for the governments of the world to ban or otherwise remove cancer-causing substances from the environment.
Dulbecco returned to southern California in 1977 to become a distinguished research professor at the Salk Institute. He became president of the institutein 1982 and held that position until his retirement in 1992. In addition, during the late 1970s Dulbecco taught at the University of California in San Diego.