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 1937
 American
 virologist
Robert C. Gallo, one of the best-known biomedical researchers in the United States, is
considered the codiscoverer, along with Luc Montagnier at the Pasteur Institute, of the
human immunodeficiency virus (HIV). Gallo established that the virus causes acquired
immunodeficiency syndrome (AIDS), something which Montagnier had not been able to
do, and he developed the blood test for HIV, which remains a central tool in efforts to
control the disease. Gallo also discovered the human T-cell leukemia virus (HTLV) and
the human T-cell growth factor interleukin-2.
Gallo's initial work on the isolation and identification of the AIDS virus has been the
subject of a number of allegations, resulting in a lengthy investigation and official
charges of scientific misconduct which were overturned on appeal. Although he has now
been exonerated, the ferocity of the controversy has tended to obscure the importance
of his contributions both to AIDS research and biomedical research in general. As
Malcolm Gladwell observed in 1990 in THE WASHINGTON POST: "Gallo is easily one of the
country's most famous scientists, frequently mentioned as a Nobel Prize contender, and
a man whose research publications were cited by other researchers publishing their own
work during the last decade more often than those of any other scientist in the world."
Gallo was born in Waterbury, Connecticut, on March 23, 1937, to Francis Anton and
Louise Mary (Ciancuilli) Gallo. He grew up in the house that his Italian grandparents
bought after they came to the United States. His father worked long hours at the welding
company which he owned. The dominant memory of Gallo's youth was of the illness and
death of his only sibling, Judy, from childhood leukemia. The disease brought Gallo into
contact with the nonfamily member who most influenced his life, Dr. Marcus Cox, the
pathologist who diagnosed her disease in 1948. During his senior year in high school, an
injury kept Gallo off the high school basketball team and forced him to think about his
future. He began to spend time with Cox, visiting him at the hospital, even assisting in
postmortem examinations. When Gallo entered college, he knew he wanted a career in
biomedical research.
Gallo attended Providence College, where he majored in biology, graduating with a
bachelor's degree in 1959. He continued his schooling at Jefferson Medical College in
Philadelphia, where he got an introduction to medical research. In 1961 he worked as a
summer research fellow in Alan Erslev's laboratory at Jefferson. His work studying the
pathology of oxygen deprivation in coal miners led to his first scientific publication in
1962, while he was still a medical student.
In 1961 Gallo married Mary Jane Hayes, a woman he knew from his hometown whom he
had begun dating in his first year of college. Together they had two children. Gallo
graduated from medical school in 1963; on the advice of Erslev, he went to the University
of Chicago because it had a reputation as a major center for blood-cell biology, Gallo's
research interest. From 1963 to 1965 he did research on the biosynthesis of hemoglobin,
the protein that carries oxygen in the blood.
Treats Cancer Patients
In 1965 Gallo was appointed to the position of clinical associate at the National Institutes
of Health (NIH) in Bethesda, Maryland. He spent much of his first year at NIH caring for
cancer patients. Despite the often depressing work environment, he observed some early
successes at treating cancer patients with chemotherapy. Children were being cured of
the very form of childhood leukemia that killed his sister almost twenty years before. In
1966, Gallo was appointed to his first full-time research position, as an associate of
Seymour Perry, who was head of the medicine department. Perry was studying how white
blood cells grow in various forms of leukemia. In his laboratory Gallo studied the
enzymes involved in the synthesis of the components of deoxyribonucleic acid (DNA), the
carrier of genetic information.
The expansion of the NIH and the passage of the National Cancer Act in 1971 led to the
creation of the Laboratory of Tumor Cell Biology at the National Cancer Institute (NCI), a
part of the NIH. Gallo was appointed head of the new laboratory. He had become
intrigued with the possibility that certain kinds of cancer had viral origins, and he set up
his new laboratory to study human retroviruses. Retroviruses are types of viruses which
possess the ability to penetrate other cells and splice their own genetic material into the
genes of their hosts, eventually taking over all of their reproductive functions. At the time
Gallo began his work, retroviruses had been found in animals; the question was whether
they existed in humans. His research involved efforts to isolate a virus from victims of
certain kinds of leukemia, and he and his colleagues were able to view a retrovirus
through electron microscopes. In 1975, Gallo and Robert E. Gallagher announced that
they had discovered a human leukemia virus, but other laboratories were unable to
replicate their results. Scientists to whom they had sent samples for independent
confirmation had found two different retroviruses not from humans, but from animals.
The samples had been contaminated by viruses from a monkey or a chimp and the idea
that a virus could cause cancer was publicly ridiculed.
Despite the humiliation Gallo suffered and the damage this premature announcement
did to his reputation, he continued his efforts to isolate a human retrovirus. He turned
his attention to T-cells, white blood cells which are an important part of the body's
immune system, and developed a substance called T-cell growth factor (later called
interleukin-2), which would sustain them outside the human body. The importance of this
growth factor was that it enabled Gallo and his team to sustain cancerous T-cells long
enough to discover whether a retrovirus existed within them. These techniques allowed
Gallo and his team to isolate a previously unknown virus from a leukemia patient. He
named the virus human T-cell leukemia virus, or HTLV, and he published this finding in
SCIENCE in 1981. This time his findings were confirmed, and as Michael Specter noted in
the NEW YORK REVIEW OF BOOKS, Gallo was "transformed from a loser to a star."
Develops Blood Test for the AIDS Virus
It was Gallo's experience with viral research that made him so important in the effort to
identify the cause of AIDS, after that disease had first been characterized by doctors in
the United States. In further studies of HTLV, Gallo had established that it could be
transmitted by breast-feeding, sexual intercourse, and blood transfusions. He also
observed that the incidence of cancers caused by this virus was concentrated in Africa and
the Caribbean. HTLV had these and other characteristics in common with what was then
known about AIDS, and Gallo was one of the first scientists to hypothesize that the
disease was caused by a virus. In 1982, the National Cancer Institute formed an AIDS
task force with Gallo as its head. In this capacity he made available to the scientific
community the research methods he had developed for HTLV, and among those whom
he provided with some early technical assistance was Luc Montagnier at the Pasteur
Institute in Paris.
Gallo tried throughout 1983 to get the AIDS virus to grow in culture, using the same
growth factor that had worked in growing HTLV, but he was not successful. Finally, a
member of Gallo's group named Mikulas Popovic developed a method to grow the virus
in a line of T-cells. The method consisted, in effect, of mixing samples from various
patients into a kind of a cocktail, using perhaps ten different strains of the virus at a
time, so there was a higher chance that one would survive. This innovation allowed the
virus to be studied, and observing the similarities to the retroviruses he had previously
discovered, Gallo called it HTLV-3. In 1984, he and his colleagues published their
findings in SCIENCE. Gallo and the other scientists in his laboratory were able to establish
that this virus caused AIDS, and they developed a blood test for the virus. In a 1993
issue of NEW YORK TIMES MAGAZINE, Nicholas Wade writes: "After twelve grim years, Gallo's
blood test is still the only weapon of real value that scientists have yet managed to
devise against this baffling disease."
Photo: Courtesy of the National Library of Medicine.
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