In memoriam: David Baltimore

David Baltimore, Nobel laureate and president emeritus at the California Institute of Technology, died September 6, at the age of 87. Baltimore was a world-renowned researcher, educator and scientific advocate who made significant contributions to molecular biology and genetics. He was a member of the American Society for Biochemistry and Molecular Biology for over 50 years.

David Baltimore

Born in New York City in 1938, Baltimore earned his Ph.D. from Rockefeller University in 1962. He conducted postdoctoral and early career work on viral replication and enzymology at the Massachusetts Institute of Technology, Albert Einstein College of Medicine and the Salk Institute for Biological Studies. While at Salk, he met a fellow scientist, Alice Huang, whom he married in 1968.

In 1968, Baltimore joined MIT as an associate professor of microbiology, where he and Huang studied an RNA-dependent polymerase in a livestock virus. They expanded this work to tumor-causing RNA viruses that infect mice and chickens, leading to the ground-breaking discovery of reverse transcriptase — an enzyme that synthesizes DNA from RNA. This discovery challenged the central dogma of molecular biology and led to the classification of retroviruses, which use RNA to make viral DNA and includes human immunodeficiency virus, or HIV. He published his work in a single-author paper in Nature.

For this discovery, Baltimore was awarded the Nobel Prize for physiology or medicine in 1975 along with Howard Temin and Renato Dulbecco. Baltimore was 37 years old.

Before receiving the Nobel Prize, Baltimore was widely recognized for his contributions to biomedical research. He received the Gustave Stern Award in Virology in 1970, Eli Lilly and Company Award in Microbiology and Immunology in 1971, and was elected to the National Academy of Sciences and American Academy of Arts and Sciences in 1974.

Baltimore was an early member of the MIT Center for Cancer Research. In 1982, he worked with philanthropist Edwin C. Whitehead to cofound the Whitehead Institute for Biomedical Research, or WIBR, a nonprofit institute dedicated to basic biomedical research. The institute became an important partner in the Human Genome Project.

As director of WIBR, Baltimore continued pioneering research, including discovering the immune-regulating transcription factor NF-κB with Ranjan Sen. His lab also produced key findings, such as George Daley’s work on the fusion protein BCR–ALB, which results from the combination of the BCR and ABL genes. Daley and Baltimore demonstrated that this protein was a driver of the cancer chronic myeloid leukemia, which helped pave the way for the anticancer drug imatinib. Baltimore’s lab also discovered and characterized the genes RAG1 and RAG2, which are crucial for development of the adaptive immune system.

In 1997, Baltimore was appointed president of the California Institute of Technology. He stepped down in 2005 but continued his research until 2019 as president emeritus and a distinguished professor of biology. At the time, his lab studied the immune system and developed viral vectors to enhance the anticancer immune response. His lab also continued to focus on basic genetic concepts such as homologous recombination. A postdoctoral fellow in his lab, Matthew Porteus was the first to demonstrate the application of precise gene editing in human cells.

Beyond his research, Baltimore was a prominent advocate in science policy, addressing issues such as the AIDS epidemic and recombinant DNA research. He co-chaired the National Academy of Sciences committee on a national strategy for AIDS in 1986 and served as head of the National Institutes of Health AIDS Vaccine Research Committee in 1996. He co-organized the Asilomar Conference on Recombinant DNA in 1975, a landmark meeting of scientists aimed at establishing guidelines for the use of recombinant DNA technology. He remained vocal about this topic — he and other scientists called for a worldwide suspension on using genome-editing technology to alter inheritable human DNA in 2005.

Baltimore published over 700 peer-reviewed research articles and held almost 100 patents. He received many honors recognizing his contributions to science. In 1999, President Bill Clinton awarded Baltimore the National Medal of Science. His contributions to biomedical research were also recognized internationally — he received the Canada Gairdner International Award in 1974 and was elected as a foreign member of the Royal Society in the United Kingdom in 1987. In 2019, Caltech founded a biochemistry and molecular biophysics graduate fellowship program in honor of Baltimore. His received the Laske–Koshland Special Achievement Award in Medical Science 2021 in recognition of his lifetime of achievements.

In an obituary posted by the Broad Institute, Eric Lander, professor of biology at MIT and former scientific advisor to Presidents Barack Obama and Joe Biden, summarized Baltimore’s legacy: “Without David Baltimore, the entire scientific enterprise — generations of amazing scientists, many vibrant new institutions, our knowledge of biomedicine — would be much poorer.”

Outside of his research and advocacy work, Baltimore enjoyed fly fishing at his home in Montana.

Baltimore is survived by his wife, daughter and granddaughter.