American molecular biologist (1938–)

Baltimore was born in New York City and studied chemistry at Swarthmore College. He continued with postgraduate work at the Massachusetts Institute of Technology, and at Rockefeller University, where he obtained his PhD in 1964. After three years at the Salk Institute in California, he returned to MIT in 1968 where, in 1972, he became professor of biology.

Francis Crick had formulated what came to be known as the Central Dogma of molecular biology, namely, that information could flow from DNA to RNA to protein but could not flow backward from protein to either DNA or RNA. Although he had not actually excluded the passage of information from RNA to DNA it became widely assumed that such a flow was equally forbidden. In June 1970 Baltimore and, quite independently, Howard Temin announced the discovery of an enzyme later to be known as reverse transcriptase, which is capable of transcribing RNA into DNA. Apparently certain viruses, like the RNA tumor viruses used by Baltimore, could produce DNA from an RNA template. For this work Baltimore shared the 1975 Nobel Prize for physiology or medicine with Temin and Renato Dulbecco. A few years later their work took on an added significance when Gallo and Montagnier identified a retrovirus as the cause of AIDS.

Earlier (1968) Baltimore had done important work on the replication of the polio virus. He revealed that the RNA of the virus first constructed a ‘polyprotein’ (or giant protein molecule), which then split into a number of smaller protein molecules. Two of these polymerized further RNA while the remainder formed the protein coat of the new viral particles.

In 1982 Baltimore became founding director of the Whitehead Institute, Cambridge, Massachusetts, a research biomedical foundation backed by the industrialist E. C. Whitehead. While at Whitehead, in collaboration with D. Schatz, he identified two antibody genes, RAG-1 and RAG-2. In 1990 Baltimore was appointed president of Rockefeller University; it was not to prove a fruitful or happy time. Many staff opposed the appointment and Baltimore became involved in a bitter controversy. It had been claimed that a paper co-authored by Baltimore and published in 1986 in Cell was based on falsified data. Although Baltimore withdrew his name from the paper, the public controversy persisted in Congressional hearings and the correspondence columns of Nature. Baltimore resigned the presidency in 1992 and returned to MIT in 1994 as professor of molecular biology.

The American virologist David Baltimore (born 1938) received the Nobel Prize in Physiology and Medicine for his work on retrovirus biochemistry and its significance for cancer research.

David Baltimore was born on March 7, 1938, in New York City, the son of Richard I. and Gertrude (Lipschitz) Baltimore. While still a high school student, he spent a summer at the Jackson Memorial Laboratory in Bar Harbor, Maine, experiencing biology under actual research conditions. This so affected him that upon entering Swarthmore College in 1956 he declared himself a biology major. Later he switched to chemistry to complete a research thesis and graduated in 1960 with a B.A. and high honors. Between his sophomore and junior years at Swarthmore, he spent a summer at the Cold Spring Harbor Laboratories, where the influence of George Streisinger led him to molecular biology.

Baltimore spent two years of graduate work at Massachusetts Institute of Technology (MIT) in biophysics, then left for a summer with Philip Marcus at the Albert Einstein Medical College and to take the animal virus course at Cold Spring Harbor under Richard Franklin and Edward Simon. He then joined Franklin at the Rockefeller Institute, completing his thesis by 1964 and staying on as a postdoctoral fellow in animal virology with James Darnell.

In 1965 he became a research associate at the Salk Institute of Biological Studies, working in association with Renato Dulbecco. Here he first met Alice S. Huang, with whom he also conducted research. He and Huang were married on October 5, 1968, and that same year they returned to MIT, where he held the position of associate professor of microbiology until 1971. In 1972 he rose to full professorship, and in 1974 he joined the staff of the MIT Center for Cancer Research under Salvador Luria.

Received Recognition For Cancer and Immunology Research

Baltimore received many awards for his work. In 1971 he was the recipient of the Gustav Stern award in virology, the Warren Triennial Prize, and the Eli Lilly and Co. award in microbiology and immunology. A year after being promoted to full professorship at MIT, he was rewarded a lifetime research professorship by the American Cancer Society. In 1974 he was presented with the U.S. Steel Foundation award in molecular biology and the Gairdner Foundation Annual Award. His most prestigious award came in 1975 when he shared the Nobel Prize in Physiology and Medicine with Howard M. Temin and Renato Dulbecco for research on retro-viruses and cancer. Much of this work concentrated upon protein and nucleic acid synthesis of RNA (ribonucleic acid) animal viruses, especially polio-virus and the RNA tumor virus. His research demonstrated that the flow of genetic information in such viruses did not have to go from DNA (deoxyribonucleic acid) to RNA but could flow from RNA to DNA, a finding which undermined the central dogma of molecular biology - i.e., unilinear information flow from DNA to proteins. This process came to be called, facetiously, "reverse transcriptase."

Baltimore's interests later took him further into the study of how viruses reproduce themselves and into work on the immune systems of animals and humans, where he concentrated upon the process by which antibodies may develop. Central to much of this work was DNA technology, in which he maintained an active interest.

Baltimore proved himself an effective educator, conducting seminars with graduate students and younger colleagues. He also became successful at directing research rather than doing it himself, again working closely with students.

Research Debacle

In 1989 Thereza Imanishi-Kari, a collegue with whom he co-authored a 1986 paper on immunology for Cell, was charged with falsifying data. Imanishi-Kari, a Massachussets Institute of Technology Assistant Professor, was absolved when a top government ethics panel declared they found no wrongdoing in 1996. Although Baltimore was never implicated in any wrongdoing, the incident caused him to withdraw the paper. He was also pressured by colleagues to resign from his presidency at New York's Rockefeller University, which he did in 1991.

Baltimore Chairs AIDS Vaccine Research Panel

In December 1996, Baltimore became the head of a new AIDS vaccine research panel for the Office of AIDS Research at the National Institute of Health. The panel was formed to step up the search for an AIDS vaccine. He also became the President of the California Institute of Technology in 1997.

Further Reading

Short biographies of David Baltimore can be found in the 39th edition of Who's Who in America (1976-1977) and in the 14th edition of American Men and Women of Science: Physical and Biological Sciences (1979). He provided an autobiographical sketch in the Nobel Lectures (1977), and a New York Times interview (August 26, 1980) gives additional information.

For further reading, see: Appeals Panel Reverses Fraud Finding by K. Fackelmann in Science News, July 6, 1996; Baltimore to Head New Vaccine Panel by Jon Cohen in Science, December 20, 1996; and A Shot In the Arm by Mark Schoofs, The Village Voice, December 24, 1996.

For more information on David Baltimore, visit Britannica.com.

(bôl'tĭmôr, –mər) , 1938–, American microbiologist, b. New York City, Ph.D. Rockefeller Univ., 1964. He conducted (1965–68) virology research at the Salk Institute before becoming a professor at Massachusetts Institute of Technology in 1972. In 1970 he and his wife Alice Huang discovered a virus caused by an enzyme that could transcribe DNA into RNA. He shared the 1975 Nobel Prize in Physiology or Medicine with Renato Dulbecco and Howard Temin for his study on the connections between viruses and cancer.

Appointed president of Rockefeller Univ. in 1990, he resigned the next year after a scientific fraud scandal. A paper he coauthored was said to contain fraudulent data from another author, Dr. Thereza Imanishi-Kari, and Baltimore was criticized for his vehement defense of the paper despite the evidence. In 1996, an appeals panel overturned the verdict of the original investigating office, the federal Office of Scientific Integrity (now the Office of Reasearch Integrity), and Baltimore and Imanishi-Kari were exonerated. In 1997 Baltimore was appointed president of the California Institute of Technology.

Bibliography

See D. J. Kevles, The Baltimore Case: A Trial of Politics, Science, and Character (1998).

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