(1912 - 1991)
Salvador Edward Luria was born on August 13, 1912,
in Torino, Italy. In 1935, Luria
received his M.D. from the University of Torino. He fled to France in 1936 to escape from the fascist government of Benito Mussolini. From 1938 to 1940,
he became a Research Fellow at the Institute of Radium in Paris. He
later immigrated to the United States in 1940, to escape Nazi persecution.
After fleeing Europe, Luria was a Research Assistant
in Surgical Bacteriology at Columbia University. From 1943 to 1950,
he worked at Indiana University. In 1950, Luria was appointed by the
University of Illinois as Professor of Microbiology.
A decade later, Luria moved to MIT, where he remained
until retirement; from 1959-1964 he was the Professor of Microbiology;
in 1964, he became the Sedgwick Professor of Biology; in 1970, he was
appointed Institute Professor at the Department of Biology.
In the U.S., his work focused on the genetics of bacteriophages,
viruses that infect bacteria. His famous experiment with Max Delbrück
in 1943 demonstrated statistically that inheritance in bacteria must
follow Darwinian rather than Larmarckian principles and that mutant
bacteria occurring randomly can still bestow viral resistance without
the virus being present. The idea that natural selection affects bacteria
has profound consequences, for example, it explains how bacteria develop
In January 1947, he became a naturalized citizen of
the United States. Along with Max Delbrück and Alfred Hershey,
Luria was awarded the 1969 Nobel
Prize in Medicine. He was also a member of the National Academy
of Sciences, American Academy of Arts and Sciences, American Society
of Microbiology (President, 1967-1968).
Luria died in Lexington, Massachusetts on February
The following press release from the Royal Swedish
Academy of Sciences describes Luria’s work:
Around 1940, Delbrück, Hershey and Luria became
interested in bacteriophage, a type of virus that infects bacteria,
rather than ordinary cells. They were trying to find a living system
as simple as possible, on which to study with hope of success, fundamental
life processes, first of all self-replication. Bacteriophage soon
revealed itself to be an object of choice for such research. They
worked out rigorous quantitative methods and this turned bacteriophage
research into an exact science. They synchronized virus multiplication
and were thus able to follow in detail the various phases in the process.
They studied what happened in single cells and analyzed their results
with advanced statistical methods. They made a series of fundamental
discoveries, of which the following will be mentioned.
As a result of infection, both virus and cell undergo
drastic changes. The so-called cell-virus-complex behaves as an essentially
new system. The chemical activities of the cell are reprogrammed.
The virus loses its individuality and enters an "eclipse"
or "dark" phase, during which it can no longer be identified
as a particle. The metabolic activities which it releases can lead
in a matter of minutes to the formation of hundreds of new virus particles.
The virus particle consists principally of nucleic
acid surrounded by a protein shell. At infection the nucleic acid
is injected by a simple but extremely efficient mechanism into the
cell, while the protein shell remains outside. The role of nucleic
acid as the carrier of the genetic information of the virus was thus
demonstrated. The discovery of numerous genetic variants of the virus
showed that the latter contained more than a single gene. Soon after
genetic recombination was discovered to take place: two virus particles
simultaneously infecting the same cell can exchange parts of their
strings of genes and give origin to hybrid forms. This phenomenon
made possible a detailed analysis of the genetic structure of the
virus. Thanks to the short reproduction time of the virus and the
large number of progeny virus obtained, bacteriophage work, in a matter
of hours, can yield information that with other virus material might
require months or years.
The work of Delbrück, Hershey and Luria has
had a great impact on biology in general. Bacteriophages have served
and continue to serve as models for the more complicated and less
approachable systems represented by animal and human cells. Delbrück,
Hershey and Luria have set the solid foundations on which modern molecular
biology rests. Without their contributions the explosive development
of this field would have been hardly possible. From the medical point
of view, the discoveries for which the award is now given first of
all imply a deeper insight into the nature of viruses and of virus
diseases. Indirectly they also bring about an increased understanding
of the mechanism of inheritance and of those mechanisms that control
the development growth and function of tissues and organs. Over the
years our debt of gratitude to the three leading figures of bacteriophage
research has continually increased.
Prize Biography; nobelprize.org