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My
history is not atypical of many Americans: born in the midwest, educated
in the East, and now living in the West. My early years were shared between
Des Moines, Iowa and Cincinnati, Ohio. Shortly after I was born on May
28, 1942 in Des Moines, my father, Lawrence, was drafted into the United
States Navy. I was named for my father's younger brother who died of Hodgkin's
disease at the age of 24. We moved to Boston briefly where my father enrolled
in Naval officer training school before being sent to the south Pacific.
He served as a communications officer for the remainder of World War II
on an island called Eniwetok where the first hydrogen bomb was detonated
a decade later.
During my father's absence, my mother, Miriam, and I lived in Cincinnati
where her mother, Mollie Spigel, also lived. Prior to moving to Cincinnati,
Mollie had lived in Norfolk, Virginia, where she raised three children
after her husband Benjamin was killed at age 50 in a traffic accident.
Besides many special memories of my maternal grandmother, I have many
fond reminiscences of my paternal grandfather, Ben, who emigrated to the
United States in 1896 as a young boy from Moscow. He grew up in Sioux
City, Iowa, as did my father with many other Russian Jews. Shortly after
the end of World War II, we returned to Des Moines where I attended primary
school and my brother, Paul, was born. In 1952, we moved back to Cincinnati
with the hope that my father would be able to find a much better job as
an architect. In Cincinnati, he practiced architecture for the next 25
years, which enabled him to provide a very comfortable home for his family.
During my time at Walnut Hills High School, I studied Latin for five years,
which was to help me immensely later in the writing of scientific papers.
But I found high school rather uninteresting and was most fortunate to
be accepted by the University of Pennsylvania where I majored in Chemistry.
The intellectual environment of the University of Pennsylvania was extraordinary--there
were so many internationally renowned scholars who were invariably receptive
to the intrusions of undergraduate students even before the days of student
evaluations of the faculty. The small size of the undergraduate student
body undoubtedly contributed to the accessibility of the faculty. Besides
numerous science courses, I had the opportunity to study philosophy, the
history of architecture, economics, and Russian history in courses taught
by extraordinarily knowledgeable professors. Although I was among the
smallest of the heavyweight crew team members and thus had no chance of
rowing in the varsity boat, I greatly enjoyed the many hours that I spent
at this wonderful sport.
During the
summer of 1963 between my junior and senior years, I began a research
project on hypothermia in the Department of Surgery with Sidney Wolfson.
I quickly became fascinated by the project and continued working on it
throughout my senior year. I decided to remain at Penn for Medical School
largely because of the wonderful experience of doing research with Sidney
Wolfson. During the second year of medical school, I decided to ask Britton
Chance if he would allow me to study the surface fluorescence of brown
adipose tissue in Syrian golden hamsters as they arose from hibernation.
Chance had reported that the surface fluorescence of other organs reflected
the oxidation-reduction state of those tissues. As anticipated, large
changes in the fluorescence of brown fat were found during non-shivering
thermogenesis.
My research
on brown fat allowed me to spend much of the fourth year of medical school
at the Wenner-Gren Institute in Stockholm working with Olov Lindberg on
the metabolism of isolated brown adipocytes. This was an exciting time
and I began to consider seriously a career in biomedical research. Early
in 1968, 1 returned to Philadelphia to complete my medical studies and
to contemplate my options. The previous spring, I had been given a position
at the NIH once I completed an internship in medicine. It was the height
of the Vietnam war with 500,000 young Americans trying to control the
spread of Communism in southeast Asia. But I was facing an internship
at the University of California San Francisco (UCSF) that would require
me to work every other night for an entire year, a prospect about which
I was not enthusiastic. The privilege of serving in the US Public Health
Service at the NIH clearly outweighed the unpleasant prospects of an internship.
Although the workload was awesome, I managed to survive because San Francisco
was such a nice place to live. During that year, I met my wife, Sandy
Turk, who was teaching mathematics to high school students.
At the NIH,
I worked in Earl Stadtman's laboratory where I studied glutaminases in
E. coli. My three years at the NIH were critical in my scientific education.
I learned an immense amount about the research process: developing assays,
purifying macromolecules, documenting a discovery by many approaches,
and writing clear manuscripts describing what is known and what remains
to be investigated. As the end of my time at the NIH began to near, I
examined postdoctoral fellowships in neurobiology but decided a residency
in Neurology was a better route to developing a rewarding career in research.
The residency offered me an opportunity to learn about both the normal
and abnormal nervous system.
In July 1972,
I began a residency at the University of California San Francisco in the
Department of Neurology. Two months later, I admitted a female patient
who was exhibiting progressive loss of memory and difficulty performing
some routine tasks. I was surprised to learn that she was dying of a "slow
virus" infection called Creutzfeldt-Jakob disease (CJD) which evoked no
response from the body's defenses. Next, I learned that scientists were
unsure if a virus was really the cause of CJD since the causative infectious
agent had some unusual properties. The amazing properties of the presumed
causative "slow virus" captivated my imagination and I began to think
that defining the molecular structure of this elusive agent might be a
wonderful research project. The more that I read about CJD and the seemingly
related diseases--kuru of the Fore people of New Guinea and scrapie of
sheep--the more captivated I became. Over
the next two years I completed an abbreviated residency while reading
every paper that I could find about slow virus diseases. In time, I developed
a passion for working on these disorders. As I plotted out a course of
action, the task became more and more daunting. The tedious, slow, and
very expensive assays in mice for the scrapie agent had restricted progress
and I had no clever idea about how to circumvent the problem. I did think
that after working with the scrapie agent for some time that I might eventually
be able to develop such an assay.
Since both
Sandy and I liked living in San Francisco, I accepted the offer of an
assistant professor position from Robert Fishman, the Chair of Neurology,
and began to set up a laboratory to study scrapie in July 1974. Although
many people cautioned me about the high risk of studies on scrapie due
to the assay problems, such warnings did not dull my enthusiasm. To gain
a base of research support from the NIH, I initially wrote grant proposals
on glutamate metabolism in the choroid plexus. Such proposals were dull
but were readily funded because I had worked on glutaminases earlier.
Eventually, I managed to gain modest NIH support for my scrapie studies
but this was not without considerable difficulty. To rebut the disapproval
of my first NIH application on scrapie, I set up a collaboration with
William Hadlow and Carl Eklund who were working at the Rocky Mountain
Laboratory in Hamilton, Montana. They taught me an immense amount about
scrapie and helped me initiate studies on the sedimentation behavior of
the scrapie agent.
I had anticipated
that the purified scrapie agent would turn out to be a small virus and
was puzzled when the data kept telling me that our preparations contained
protein but not nucleic acid. About this time, I was informed by the Howard
Hughes Medical Institute (HHMI) that they would not renew their support
and by UCSF that I would not be promoted to tenure. When everything seemed
to be going wrong, including the conclusions of my research studies, it
was the unwavering, enthusiastic support of a few of my closest colleagues
that carried me through this very trying and difficult period. Fortunately,
the tenure decision was reversed and I was able to continue my work. Although
my work was never supported by HHMI again, I was extremely fortunate to
receive much larger funding from the R. J. Reynolds Company through a
program administered by Fred Seitz and Macyln McCarty and shortly thereafter
from the Sherman Fairchild Foundation under the direction of Walter Burke.
While the vast majority of my funding always came from the NIH, these
private sources were crucial in providing funds for the infrastructure
which was the thousands of mice and hamsters that were mandatory.
As the data
for a protein and the absence of a nucleic acid in the scrapie agent accumulated,
I grew more confident that my findings were not artifacts and decided
to summarize that work in an article that was eventually published in
the spring of 1982. Publication of this manuscript, in which I introduced
the term "prion", set off a firestorm. Virologists were generally incredulous
and some investigators working on scrapie and CJD were irate. The term
prion derived from protein and infectious provided a challenge to find
the nucleic acid of the putative "scrapie virus." Should such a nucleic
acid be found, then the word prion would disappear! Despite the strong
convictions of many, no nucleic acid was found; in fact, it is probably
fair to state that Detlev Riesner and I looked more vigorously for the
nucleic acid than anyone else. While
it is quite reasonable for scientists to be skeptical of new ideas that
do not fit within the accepted realm of scientific knowledge, the best
science often emerges from situations where results carefully obtained
do not fit within the accepted paradigms. At times the press became involved
since the media provided the naysayers with a means to vent their frustration
at not being able to find the cherished nucleic acid that they were so
sure must exist. Since the press was usually unable to understand the
scientific arguments and they are usually keen to write about any controversy,
the personal attacks of the naysayers at times became very vicious. While
such scorn caused Sandy considerable distress, she and my two daughters,
Helen and Leah, provided a loving and warm respite from the torrent of
criticism that the prion hypothesis engendered. During the winter of 1983,
I herniated a disc in my lumbar spine while skiing and this slowed the
pace of my work for much of the year. After a laminectomy, I began swimming
regularly, which brought relaxation and a much needed quiet time to my
life.
Just prior
to my back problem, the protein of the prion was found in my laboratory
and the following year, a portion of the amino acid sequence was determined
by Leroy Hood. With that knowledge, molecular biological studies of the
prions ensued and an explosion of new information followed. I collaborated
with Charles Weissmann on the molecular cloning of the gene encoding the
prion protein (PrP) and with George Carlson and David Kingsbury on linking
the PrP gene to the control of scrapie incubation time in mice. About
the same time, we succeeded in producing antibodies that provided an extremely
valuable tool that allowed us to discover the normal form of PrP. In a
very important series of studies, the antibodies were used by Stephen
DeArmond to study the pathogenesis of prion disease in transgenic mice.
Steve brought the much needed talents of an outstanding neuropathologist
to these studies. As more data accumulated, an expanding edifice in support
of the prion concept was constructed. Ruth Gabizon dispersed prions into
liposomes and purified scrapie infectivity on columns with PrP antibodies.
Karen Hsiao discovered a mutation in the PrP gene that caused familial
disease and reproduced the disease in transgenic mice while Michael Scott
produced transgenic mice abrogating the prion species barrier and later
artificial prions from chimeric PrP transgenes. Indeed, no experimental
findings that might overturn the prion concept were reported from any
laboratory. By the early 1990s, the existence of prions was coming to
be accepted in many quarters of the scientific community, but the mechanism
by which normal PrP was converted into the disease-causing form was still
obscure. When Fred Cohen and I began to collaborate on PrP structural
studies, I was again extremely fortunate. Fred brought an extraordinary
set of skills in protein chemistry and computational biology to investigations
of PrP structures.
As prions gained
wider acceptance among scientists, I received many scientific prizes.
The first major recognition of my work was accorded by neurologists with
many other awards coming soon thereafter. But the most rewarding aspect
of my work has been the numerous wonderful friends that I have made during
an extensive series of collaborative studies. It has been a special privilege
to work with so many talented scientists including numerous postdoctoral
fellows and technical associates who have taught me so much. Besides the
many collaborators who have contributed their scientific skills to advancing
the study of prions, I have had many colleagues who have contributed indirectly
to my work by being supportive of the special needs that such a project
has demanded.
From Les Prix Nobel
1997.
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