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Biotechnology at 25: Perspectives on History, Science,
and Society
Saturday, March 13, 1999
William
Rutter, Ph.D.
Co-founder of Chiron Corp. and Professor of
Biochemistry, Emeritus, University of California, San
Francisco.
William Rutter: Hearing Jim's talk and seeing
the painting of Dalí's Hommage to Watson and
Crick reminds me of an incident. I don't think I've
ever mentioned to Jim. One time, nearly twenty years
ago, or there abouts, I was going into Chicago late
at night and turned on the television to try to get
some news and there was a talk show in Chicago called
the Herb Cupsnit Show and it turned out that Herb Cupsnit,
that night was interviewing Salvador Dalí and
on the screen was Hommage to Watson and Crick. So Cupsnit
said, "Well, Mr. Dalí, what is the motivation
for this Hommage to Watson and Crick?" And Dalí said, "First,
I love my wife, then I love money, then I love dioxyribonucleic
acid."
[Rutter: laughs audience: laughs]
Now in the short time that I have up here I'd just
like to record briefly the transition of myself from
a confirmed academic to a confirmed commercially oriented
scientist and executive in an attempt to essentially
deliver products to human beings and in that course
I've had the great good pleasure, of course, working
with Ed Penhoet, my colleague for many years and also
Pablo Vallenzuela and many, many people, some of whom
are in this audience. But for today's discussion I
just want to emphasize almost the explosive effect
of the Cohen-Boyer experiment on people who are working
in the field particularly those interested in expression
of genes in higher organisms. And thus it was particularly
pungent for the group at UCSF because that kind of
orientation had been the direction in which we'd been
recruiting people. Clearly, we wanted to work on higher
organisms and we had an extremely close relationship
with the clinical departments which supported our activities
significantly. And in that sense, that particular department
was a little bit different than many departments which
existed in medical schools at the time.
So, in my own case, we were -- I was interested in
expression of genes the development of the pancreas
and one of those happened to be insulin and Howard
Gooden and our groups got together and eventually cloned
the insulin gene. And then after that cloning and actually
during the process itself the whole department was
alive with discussions about the utility and exactly
the directions that cloning should take both from a
scientific standpoint and from a non-scientific standpoint.
During this time Herb and Bob Swanson were forming
Genentech and for a while they had occupied some space
in the department and so on, and so on. But the, sort
of , the crowning event which began to transition my
own point of view was a visit I was inclined to make
in fact, invited to make to a committee of the Senate,
chaired by Adelay Stevenson and Senator Schmitt to,
in fact, investigate the dangers of recombinant DNA
and alleged infringement which had occurred during
the cloning and finally the benefits. I don't think
they got to the last point. But in one of the major
discussions that was associated with danger in walked
Margaret Mead, a well known specialist in the field,
and Margaret Mead had a long rope over her body and
she had a large shepherd's staff and Adelay Stevenson
gave her a great adulatory introduction and she came
up to the podium and over the next quite a long period
of time she emphasized that scientists after her would
be proclaiming that this technology was safe. They
are clearly wrong. And instead there was a huge danger
behind this program. Later on, why, there was a tricky
discussion which is, in fact, continued for nearly
twenty years now. On the same subject and on the particular
aspects of those early experiments, well, I became
not only involved personally at that time but intellectually
in the sense that I became then personally committed
to looking at the danger risk of benefit issue. And
in thinking about this I wasn't, at the time, convinced
that insulin cloning would lead to the production of
insulin for many obvious reasons. But I was looking
for a strategy in which, first of all, acknowledging
the coding itself but worrying a bit about the translation
which would occur in a microorganism of a human gene.
That is whether the fertility would be 100% when the
tRNA populations were dramatically different. And also
wanting to have a target which would have unassailable
benefit, and gradually I became interested, very seriously
interested, in hepatitis B. I became interested in
that because of a consulting relationship I'd had for
fifteen years with Abbot Laboratories, and they had
developed a diagnostic business. One of their major
diagnostics products was Hepatitis B, and of course
the issue of Hepatitis B infection, especially in Asian
countries was extraordinary. Literally a quarter of
a billion people in Asia were carriers of this virus;
women transmitting it to their children, and the children
then being very highly susceptible to liver cancer.
And this was, in fact, documented quite clearly via
epidemiological studies by a man named Palmer Beasley
(whose brother, by the way, lives in Berkeley). So
this looked like a good target and Hepatitis B was,
in fact, a very small virus. As it turned out, I had
been discussing the issues associated with cloning
and the vaccine itself with Roy Badgelos, who had just
moved to Merk, Sharp and Done at the time. It turned
out that they were working on the vaccine for Hepatitis
B, and the virus particles or a fraction of the samples
which they were producing from infected human sera
were DNA rich. So there was available a source of the
virus. Could we have the first slide?
So our attention was then drawn far away from Insulin
itself to Hepatitis, and next slide. Could you dim
the lights please. This is an electron micrograph of
a concentrated population virus particles form a Hepatitis
B infected individual, and you can see here that the
virus itself are these large particles called dane
particles: full viruses including the DNA. Where the
smaller particles and, in fact, the filaments ostensibly
didn't contain DNA. Next slide please. So the general
idea in the Merck proposal was to isolate the particles,
the small particle, which ostensibly didn't contain
DNA, and use these as a vaccine. This was a tremendously
difficult problem in itself, but the problem was contamination
with the DNA itself. So that kind of a vaccine had
within it both the problems of contamination with any
other adventitious virus and the problems of contamination
with the virus itself with small amounts of DNA containing
virus. So potentially you have the same kind of situation
which occurred with Polio. As you were to recall in
the 1950s when several hundred cases of Polio were
caused by the vaccine itself. This resulted in lawsuits
which resulted in term and the closing of several companies,
including Cutter Laboratories, which existed here in
Berkeley. In fact that Polio consequence in the general
industry was that all companies, there must have been
at that time at least a half of a dozen companies that
were producing vaccines, all left the field because
of the risk and, in fact, the lack of commercial reward.
Now you can see immediately in this schema the potential
that recombinant DNA had to solve this issue. If it
were possible using genetic procedures which nowhere
included the entire viral DNA to produce this small
particle, this would eliminate the chance of adventitious
infection, and also simultaneously produce a marketing
source which could potentially deal with the extraordinary
needs that the world had that the world had for a vaccine
for Hepatitis B. Next slide.
So after some discussions et cetera, Merk decided
to support this program and UCSF, and Hablo Vallencuela,
and a group of others and the laboratory began cloning
experiments with the raw material provided by Merk.
And it turned out that incidentally at UCSF in the
laboratory Buras Vias there were a few snippets of
amino acid sequence which were obtained by a man named
Roger Peterson working in his group. And in blue here
is shown the region of the virus which encodes a single
protein, actually existing in three forms, that in
large measure contributes to the envelope. In green
are the genes associated with replication and in orange
are the genes associated with the internal core. Next
slide please.
So this then gave a simple picture of the virus since
it was only 3,200 nucleotides long it was essentially
technically possible to deal with this with the available
technology which existed at that time. So the issue
was how to express the surface. And during this time
interval Hepatitis B became one of the targets that
many individuals became interested in. So, during the
cloning procedure and attempting onto expression it
became obvious that one needed a quite disciplined
approach to the expression problem; one that was not
easily accomplished in the university laboratory with
people trying to get degrees and post docs who were
interested in getting jobs immediately, and so on and
so on. Furthermore, it became obvious that the competition
was extremely warm from other groups working on this
area. And our own interests became crystallized when
I attended a meeting on the East Coast, essentially
organized by Patell, the Patell Group, on problems
in this area. And I was surprised to see when I got
there that the audience, at least half of them, were
either venture capitalists, investment bankers, company
representatives and pretty much the scientists were
overcome with interest by this group. It became pretty
obvious that my little lab was not going to be able
to compete with the resources which were being placed
on this and other problems. And so there were three
alternatives, I think, to address this. One was to
essentially work with the pharmaceutical house, and
second to develop a technology lab within UCSF, and
third was to try to do it ourselves. And we tried all
of these alternatives, kicking a screaming, trying
to start a company by ourselves. None of the pharmaceutical
houses had technology in house, nor could they ramp
up quickly. We tried significantly to do this through
another biotechnology company and became a member of
the scientific advisory board of AMGEN. But their program
was so diverse that they really couldn't focus on these
projects, the several projects which were sort of interesting
to us. And finally, the idea of having a technology
transfer lab associated with the school, although an
interesting one, was totally impractical. There wasn't
available capital; entrepreneurial capital is not usually
available to universities in general. It would have
been a controversial project, and frankly most of the
people inside would have gone to other competitive
activities.
So as a result of that we decide to form Chiron to
be competitive and we moved a group of people, I know
some of whom are in this audience today, to start Chiron
and the issue on expression then became a very important
issue: how to do it in bacteria. It turned out bacteria
expressed in small quantities this surface antigen,
but in fact never produced a particle. And so finally
we decided that, well, a virus-like particle like this
probably needed to be constituted within the context
of eucaryotic membranes. And hence we shifted to yeast.
Now in order to get the program going in yeast it was
absolutely necessary to obtain a promoter, and at that
time many people were working on promoters to drive
these genes. Some of whom were my previous colleagues
and even students. It was impossible to get a promoter.
For many of these folks there was kind of, at this
moment, a segregated competition until, sort of, the
lay of the land was established. And finally we were
able to establish a collaboration with an old colleague
from Illinois, Ben Hall, who had moved to Washington.
And we carried out these collaborations together. Next
slide.
And to our great delight, in an appropriate system
in yeast one could produce particles which were of
the same size and character that those were present
in human serum. We didn't see filaments and later on
we understood the reason why we didn't see filaments.
It’s the portion of the surface antigen gene that
we used which forms these single particles. But these
particles themselves had virtually all the same properties
as a human virus particle. So at once we solved a major
problem. We didn't know whether specific human genes
were required for the production of these particles
in human liver cells. We didn't know whether they needed
other products to form the particles. So we were delighted
that a particle like this could be formed in a totally
different genetic system. And the next question is
whether it would be utilized, and we found that, in
fact, it had the same kind of imunigenicity as particles
that could be isolated from human serum. And when the
choice was made between having the particles from yeast
and particles derived from, for example, tissue culture
cells immediately we selected yeast because of the
absence of any contaminating viruses. And of course
that was a good choice because, defacto, under these
circumstances we didn't run the risk of such a contamination,
which would have been another issue. Incidentally,
while this program was going on in yeast a program
to isolate those particles in human blood was going
on in a parallel fashion at Merk, and was, in fact,
championed by the vaccine group at Merk. So there was
a question after it was all finished whether it would
ever see the light of day, and it did so in my view,
or in our view, in large measure because of the threat
of HIV. That is, in fact, one of the crazy benefits
of such a plague on mankind. That it, in fact, contributed
to the rapid development of this vaccine and subsequently
its promulgation broadly. Now vaccines based on these
particles are sold by Merk and SKB Worldwide to tens
of millions of people, and now a program which would
eventually protect all children from Hepatitis B. So
having gone through this experience, this led to the
full commitment of the few of us who were involved
to focus on disease, itself, prevention by one way
or another. And the next project was Hepatitis non
A non B. I think I don't have time to go through that
but I will just flash through the slides. Next slide
please.
Of course that emphasized this program for diseases
control by diagnosis prevention and therapy. [next
slide] Non A non B was simply all the residual Hepatitis
that was not know to be either A or B. It wasn't known
whether one or two viruses were involved. [next slide]
A group at Chiron headed by Michael Hotton and George
Quo, and Qualim Chu finally sequenced this virus. It
is about three times bigger than Hepatitis A and a
totally different virus. [next slide] In fact related
to Flavey viruses, viruses like for example, yellow
fever but quite distinct from them. [next slide] Once
having discovered the virus you could again determine
its prevalence in its relationship to other disease.
It then became obvious that this was a major major
disease on a world-around basis. It became evident
in subsequent months and years that it was a prime
cause of liver cancer and cirrhosis, even a more aggressive
cause than Hepatitis B itself. [next slide] And, lastly,
just to emphasize the point that Ed made, the initial
cloning that it made available, on the initial stage,
the diagnostic tests which reduced the possibility
of infection over a period of years from blood, from
any use of human blood, to close to twenty five percent
in the late 1970s when we started. And then through
tests for Hepatitis B, HIV and Hepatitis C, in the
end now in 1999 it is an infinitesimal amount of infection,
about 1 in 100,000 that gets infection from any one
of these agents. And so, in one sense, the immediate
efforts through vaccination and through this kind of
prevention through metric tests has demonstrated, I
think, value over risk, and we are all happy to be
part of that.
Thank you.
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