http://nobelprize.org/nobel_prizes/medicine/laureates/2008/montagnier-autobio.html
Luc Montagnier, Nobel F. autobiography
I
was born on August 18, 1932 in Chabris, a "bourg", larger than a
village but smaller than a town, located in Berry south of the Loire
Valley. This was ’Äì and still is ’Äì a region of agriculture with some
renowned products such as welsh rabbit, goat cheeses and white
asparagus. It was the place where my mother had grown up but, in fact,
I never lived there.
On
my father's side, his parents came from Auvergne, a province in the
centre of France, made of rich plains and old volcanoes, the latter
probably being at the origin of my family name: Montagnier, the man
living in mountains.
In
his youth, my father had caught a terrible disease: streptococcal
arthritis, ending in irreversible lesions in the aortic valves. He was
therefore declared unfit for military service and had to find a
sedentary job: he became an accountant and excelled in this profession,
which implied, at that time, mainly hand-written work. He started
working in the Poitiers area and then moved a little farther north to
Châtellerault, a small city between Tours and Poitiers.
As
an only child, I was cherished by my mother, a housewife, but two
events dominated this pre-war period, of which I keep a vivid memory:
I
was badly injured by a high speed car while crossing a main road:
multiple wounds of which I keep some visible scars. After two days in a
coma, I emerged as if I was born again, at the age of 5
... and two years later came the declaration of war in 1939, while the
whole family was harvesting grapes in the vineyards of my mother's
brother. I still remember the images in a newspaper of Warsaw ruins
after a bombing by German planes.
And
then, in 1940, came the "real" war: the German invasion, my parents and
I leaving their house (close to a risky railway station), fleeing on
the roads in a little car, and finally more exposed to German bombing
during this "exodus" than if we had stayed home.
The
first year of German occupation was terrible, in that we had no food
reserves and most of the time we were starving. I was a rather puny boy
and during the four years of the war did not gain a gram! The "ersatz"
did not stimulate my appetite, when I was dreaming of chocolate and
oranges! My father had chronic enterocolitis and, worse, my grandfather
(his father) was diagnosed with rectal cancer. He died in 1947 after
terrible suffering and each time I visited him, I could see the
inexorable progression of the disease. This affected me so much that it
is probably one reason why I decided later to study medicine and to
start research on cancer.
In
June 1944, our house (so close to the railway) was partly destroyed ’àí
this time by an Allied bombing. I keep a mixed feeling of this year of
the liberation of France. It was a great relief but I could not forget
also the vision of so many dead people, civilians and soldiers, and the
images of skinny deportees released from concentration camps. I will
hate wars and their atrocities for the rest of my life.
At
high school I did well, being usually ahead of my classmates. This is
when I became curious about scientific knowledge, having left behind my
religious Catholic belief.
Following
the example of my father, who was tinkering in his leisure days with
electric batteries, I set up a chemistry laboratory in the cellar of
the new house which was requisitioned to accommodate us. There, I
enthusiastically produced hydrogen gas, sweet-smelling aldehydes and
nitro compounds (not nitro-glycerine!) that had the unfortunate habit
of blowing up in my face.
I
was delighted to read ’Äì in popularised books ’Äì the impressive progress
of physics, especially atomic physics. Being good in physics and
chemistry ’Äì but not as good in maths ’Äì I decided not to prepare to
compete for the "Grandes Ecoles" but instead to register both at the
School of Medicine and the Faculty of Sciences in Poitiers. My goal was
in fact to start a research carrier in human biology, but there was no
such specialty in Poitiers, either in Medicine or in Sciences. Since
both the Faculty and School were within walking distance, I could spend
the morning at the hospital and the afternoon attending courses in
botany, zoology and geology, which were the main disciplines of the
degree course in Sciences.
Fortunately
the new Professor of Botany, Pierre Gavaudan, was a very atypical
professor in that his scientific interests went far beyond the
classification of plants. In fact, I owe him for having opened me a
large window on what was the beginning of a new Biology, the DNA double
helix, the in vitro synthesis of proteins by ribosomes and the
structure of viruses.
At
the same time, I was installing at home a device combining a time-lapse
movie camera and a microscope, thanks to a gift by my father. This
allowed me to do my first research work. I was studying a phenomenon
known since 1908 as the phototaxy of chloroplasts: the property of some
algae living at the surface of ponds to orient their large unique
chloroplast according to the intensity of light; if the light was too
intense, the chloroplast turned inside the tubular cell to present its
edge. In dark or weaker light, the chloroplast, a flat plate, exposed
its larger surface. The phenomenon took a few minutes, which could be
analysed by time-lapse cinematography. Using different glass filters, I
could show that it was not the wavelength absorbed by the chlorophyll
(red light) which regulated the orientation of the chloroplasts but
indirectly some yellowish pigments absorbing the blue light. I was very
proud, at the age of 21, to defend this work as a small thesis at the
Faculty of Sciences of Poitiers. I was asked by my mentor, Pierre
Gavaudan, to do research also on a literature-based subject: the
L-forms of bacteria. This allowed me to make my first incursion ’Äì not
the last ’Äì into the world of filtering bacteria. I could only find the
references on this controversial subject at the library of the Institut
Pasteur in Paris. This was indeed the time when I left Poitiers for
Paris, where I was able to complete my medical studies as well as
explore some aspects of biology closer to human beings, particularly
neurophysiology, virology and oncology.
Having
been hired as an assistant at the Sorbonne at the age of 23, I started
learning old-fashioned technologies derived from Alexis Carrel's work
on chick embryo heart cultures, as well as that of human cell lines in
monolayers. Although my research was not productive at all, I keep from
this period a solid expertise of Pasteurian technologies for working in
perfectly sterile conditions without the use of antibiotics.
In
1957, the first description of infectious viral RNA from the tobacco
mosaic virus by Fraenkel-Conrat and Gierer and Schramm determined my
vocation: to become a virologist using the modern approach of molecular
biology.
I
started with the foot and mouth virus and then, in Kingsley Sanders'
laboratory at Carshalton near London, I was proud to identify for the
first time an infectious double-stranded RNA from cells infected with
the murine encephalomyocarditis virus, a small single-stranded RNA
virus. This demonstrated for the first time that RNA could replicate
like DNA by making a base-paired complementary strand.
In
order to perfect my knowledge of oncogenic viruses, I moved from
Carshalton to Glasgow where a new Institute of Virology had been
recently inaugurated, headed by a remarkable virologist, Michael
Stocker, and where many high-ranking visitors, among them Renato
Dulbecco, were spending sabbatical years.
Working
on a small oncogenic DNA virus, polyoma, I could show there, with I.
Macpherson, a new property of transformed cells, that of growing in
soft agar. Using this technique, it was easy to detect the transforming
capacity of polyoma virus and its DNA. We showed that naked DNA alone
carried all the oncogenic potential of the virus. This now looks pretty
obvious, but it was not so at that time.
Back
to France at the Institut Curie, I extended this finding to a number of
cancer cells, transformed or not by oncogenic RNA or DNA viruses.
However, this property allowed me to distinguish some in vitro steps in
the process of transformation, which were correlated with some
modifications of the plasma membrane and of the carbohydrate layer
surrounding it.
A
great mystery remained at that time: that of the replication of the
oncogenic RNA viruses, now known as retroviruses. Howard Temin (Figure
2) had proposed the hypothesis of a DNA intermediate, but other
possibilities could be considered. I myself tried to find a
double-stranded RNA specific of the Rous sarcoma virus, a virus able to
infect and transform chick embryo cells. I indeed isolated
double-stranded RNA sequences, but they were of cellular origin and
existed at the same level in non-infected cells! With Louise Harel, I
later showed that this RNA was partly coming from repetitious sequences
of DNA. In retrospect, it could at least in part represent the recently
identified interfering RNAs involved in the negative control of
messenger RNA translation.
In
1969’Äì70, the isolation of an RNA-polymerase associated with the viral
particles of the vesicular stomatitis virus led to the idea that
perhaps a key enzyme was also associated with the oncogenic RNA
viruses. Indeed, Howard Temin and Mizutani, and independently David
Baltimore, discovered in 1970 a specific enzyme associated with Rous
sarcoma virus (RSV), the reverse transcriptase (RT), capable of
reversely transcribing the viral RNA into DNA.
At
about the same time, Hill and Hillova in Villejuif, France,
demonstrated that the DNA extracted from RSV transformed cells was
infectious and carry the genetic information of the viral RNA,
confirming that the enzyme was working faithfully in infected cells.
I
myself, with P. Vigier, confirmed and extended this discovery by
showing that the infectious DNA was associated with the chromosomal DNA
of the cells, showing integration of the proviral DNA, as earlier
postulated by Temin.
Work
on the chicken RSV was extended to similar viruses in mammals, so that
many researchers at that time believed that RT activity was a new,
highly sensitive tool for detecting similar viruses in human leukaemia
and cancer. This was stimulated by the generously funded virus-cancer
program launched by America's National Institutes of Health.
Unfortunately, the hunt for human retroviruses was basically
unsuccessful but led to important basic work on the molecular biology
of animal retroviruses.
In
1972, I was asked by Jacques Monod, then head of the Institut Pasteur,
to create a research unit in the newly created Department of Virology
of the Institute. I accepted, and this new laboratory allowed me to
develop new avenues of research within the general theme of Viral
Oncology, the ultimate goal remaining the detection of viruses involved
in human cancers.
Thus,
I became interested in the mechanism of action of interferon and its
role in its expression of retroviruses. I came into this field after
having demonstrated the biological activity of interferon messenger RNA
in collaboration with two world-renowned experts in the field, Edward
and Jacqueline De Maeyer.
From
1973 on, Ara Hovanessian and his co-workers joined my unit and brought
a new dimension: the complex biochemical mechanism sustaining the
antiviral activity of this remarkable group of cellular proteins.
In
1975, two other researchers joined my unit and brought their expertise
on murine retroviruses: J. C. Chermann and his collaborator,
Françoise Barré-Sinoussi (Figure 3). The latter mastered
particularly the detection of retroviruses by their RT activity. I
convinced them to participate in a joint study inside the unit to look
again for retroviruses in human cancers. We started in 1977 with blood
samples coming from different Paris hospitals and biopsy specimens.
Two advances made in other laboratories boosted this search:
In
Villejuif, France, Ion Gresser had prepared a potent antiserum
neutralising any molecule of alpha endogenous interferon produced by
individual cells. This interferon, we realised, was produced by mouse
cells induced to express some of their endogenous retroviruses. Its
blockade by the antiserum increased by up to 50 times the production of
endogenous retroviruses in the culture medium. We could conclude that,
despite the fact that endogenous retroviruses have been integrated in
the genome of vertebrates for millions of years, their expression is
still controlled by the interferon system, like that of exogenous
viruses.
At
about the same period, the discovery by Denis Morgan and Frank Ruscetti
in Dr. Gallo's laboratory of a growth factor allowing the in vitro
multiplication of human T lymphocytes (TCGF, then named interleukin 2,
Il2) made it possible to propagate T lymphocytes in sustained cultures.
We
knew at that time that some retroviruses involved in mouse mammary
tumour formation (MMTV) could not only be expressed in the tumour cells
but also in the circulating lymphocytes.
Taking
advantage of these two advances, we started a search for retroviruses
in human cancers. Using anti-interferon serum and Il2, we focused
particularly on the T lymphocyte cultures from breast cancer patients.
Indeed,
in 1980, we were able to detect a DNA sequence close to that MMTV, not
only in the cells of an inflammatory breast cancer (from a North
African woman), but also in her cultured T lymphocytes. A second
patient showed similar results.
Unfortunately,
the molecular tools we had at that time could not tell us whether we
were dealing with endogenous retroviral sequences or with an exogenous
virus. Nowadays, having access to more powerful technologies, I am
planning to reinitiate these studies.
But
in 1983, the same approach, the use of anti-interferon serum, and the
use of long term cultures of T lymphocytes greatly facilitated the
isolation of HIV.
My
involvement in AIDS began in 1982, when the information circulated that
a transmissible agent ’Äì possibly a virus ’Äì could be at the origin of
this new mysterious disease. At that time there were only a few cases
in France, but they attracted the interest of a group of young
clinicians and immunologists. They were looking for virologists,
especially retro-virologists, as a likely hypothesis was that HTLV ’Äì
the only human retrovirus known so far, recently described by R. C.
Gallo ’Äì could be involved. Retrovirus causing leukaemia in rodents
often also causes a wasting syndrome, which could be the result of
secondary immune depression. This was also the case of patients
suffering from leukaemia induced by HTLV.
A
member of the working group, Françoise Brun-Vézinet, was
a former student of the virology course that I was then directing. She
called me up to organise the search for the putative retrovirus from a
patient presenting with an early sign of the disease, lymphodenopathy.
The patient was a young gay man who had been travelling to the USA and
who was consulting Dr. Willy Rozenbaum ’Äì one of the leaders of the
working group ’Äì for a swollen lymph node in the neck.
The
reasoning was that if we were to find a virus at this early stage of
the disease, it could be more a cause than a consequence of the immune
depression.
Another
incentive to start this research was a request from the producers of
hepatitis B virus vaccine in the industrial subsidiary of the Institut
Pasteur. They were using plasmas from American blood donors and were
concerned by the risk of transmission of the AIDS agent through their
procedure of viral antigen purification.
The
lymph node biopsy arrived on January 3, 1983, a date which I remember
well because it was also the first day of the virology course at the
Institut Pasteur, which I had to introduce. I could only dissect the
small hard piece at the end of the day. I dissociated the lymphocytes
with a Dounce glass homogeniser and started their stimulation in
culture with a bacterial mitogen, Protein A, known as an activator of B
and T lymphocytes, since I did not know which fraction of lymphocytes
could produce the putative virus. Three days later, I added the T cell
growth factor I had obtained from a colleague working in the laboratory
of Jean Dausset.
The
T cells grew well. As previously established in a protocol for the
search of retrovirus in human cancers, it was decided with my
associates, Françoise Barré-Sinoussi and Jean-Claude
Chermann, to measure the RT activity in the culture medium every 3
days. On day 15, Françoise showed me a hint of positivity
(incorporation of radioactive thymidine in polymeric DNA), which was
confirmed the following week.
We had evidence of a retrovirus, but this was just the beginning of a series of questions:
’Ä¢ Was it close to HTLV or not?
’Ä¢ Was it a passenger virus or, on the contrary, the real cause of the disease?
In
order to answer these basic questions, we had to characterise the virus
biochemically and immunologically, and to do that, we needed to
propagate it in sufficient amounts. Fortunately, the virus could be
easily propagated on activated T lymphocytes from adult blood donors.
No cytopathic effect was observed with this first isolate, but unlike
HTLV infected cultures, no transformed immortalised cell lines could
emerge from the cultures, which always died after 3’Äì4 weeks as do
normal lymphocytes.
By
contrast, subsequent isolates I made from culture of lymphocytes of
sick patients with AIDS were cytopathic for T lymphocytes culture and ’Äì
we discovered later ’Äì could be cultivated in larger amounts in tumour
cell lines derived from leukaemia.
Shortly
after the virus isolation, my co-workers and I were able to show that
it was not immunologically related to HTLV, and in electron microscopy,
it was very different from HTLV viral particles. In fact, as soon as
June 1983, I noticed the quasi-identity of our virus with the published
electron microscopy pictures of the visna virus in sheep, the
infectious anaemia virus in horses and the bovine lymphocytic virus: it
was a retrolentivirus, a sub-family of viruses causing long-lasting
disease in animals without immunodeficiency.
This
indicated clearly that we were dealing with a virus very different from
HTLV, and my task was now to organise a team of researchers to
accumulate evidence that this new virus was indeed the cause of AIDS.
It
was an exciting period, since every Saturday morning when we had a
meeting in my office, new data were brought by my associates favouring
the causative role of the virus. The viral isolates were called LAV,
for Lymphadenopathy Associated Virus, when it was isolated from
patients displaying swollen lymph nodes, a frequent sign of the early
phase of infection. The isolates made from patients with full-blown
AIDS were called Immuno Deficiency Associated Viruses (IDAV). The
latter generally grew better in T lymphocyte culture and induced the
formation of large syncitia, resulting from the fusion between several
infected cells. Some of them ’Äì we found out later ’Äì could also multiply
in continuous cell lines of B or T cell origin. The latter property
greatly facilitated the mass production of the virus for commercial use.
By
September 1983, I was able to make a synthesised presentation of all
our data favouring a causal link between the virus and the disease at a
meeting on the HTLV organised by L. Gross and R. Gallo at Cold Spring
Harbor.
This
presentation was received with scepticism by a small audience (it was a
late night session) and the HTLV theory still prevailed. Mentally, most
attendants were not prepared to accept the idea of a second family of
retroviruses (lentiretroviruses) existing in humans and causing immune
deficiency, and having no counterpart in animals!
This
situation is not infrequent in science, since new discoveries often
raise controversy. The only problem is that it was a matter of life and
death for blood transfused people and haemophiliacs, since a serologic
blood test using our virus antigen was already working at laboratory
scale but awaited industrial and commercial development.
This
came in 1985, after two other teams of researchers, first that of Dr.
Gallo at the NIH in early 1984 and that of Jay Levy in San Francisco,
confirmed and extended our findings. In particular, Dr. Gallo and his
associates gave more strength to the correlation between the virus and
the disease, improved the detection of the antibody response and were
able to grow several viral strains, including ours, in T cell lines of
cancer origin. Meanwhile, my co-workers showed the tropism of the virus
for CD4T cells and identified the CD4 surface molecule as the main
receptor to the virus.
The
rest of the story is described in the next chapter. I would just like
to illustrate how I discovered what I believe are two important
phenomena for explaining the destruction of the immune system induced
by HIV.
During
the latent phase of the infection, no virus is found in the blood. It
is mostly localised in lymphocytes of lymphatic tissues and yet, we
found that most of the lymphocytes present in the blood are sick! In
1987, a young visitor from Sweden, Jan Alberts, came to my lab. He
wanted to cultivate human lymphocytes in a serum-free synthetic medium
and to learn some technologies about HIV culture. The surprise came
when we compared the viability in his medium of lymphocytes from
healthy donors and those from HIV infected patients, even in their
early asymptomatic stage of infection. While the former could survive
several days without dying, the majority (more than 50%) of the latter
died very quickly. Addition of interleukin 2 partially prevented their
death.
When
we used normal culture medium supplemented with foetal calf serum, the
same difference was observed, although the survival time of the
lymphocytes from infected patients was longer.
It
did not take very long before three of my collaborators found the
reason for such deaths: apoptosis. This is an active process by which
the cell "decides" to die in a clean way, without releasing too many
toxic compounds into the medium.
It
is a physiological way of preventing abnormal proliferation of
activated lymphocyte clones, but here the phenomenon was enormous and
bore not only on the main cellular target of HIV infection, CD4+
T-lymphocytes, but also on cells which were not infectable by the
virus, such as CD8+ T-lymphocytes, B-lymphocytes, monocytes, natural
killer cells ... Clearly, it was a general phenomenon, the culture
simply revealing a predisposition to apoptosis of the majority of
circulating blood cells, although most of them were not infected.
Indeed, my collaborator Marie-Lise Gougeon found a very good relation
between in vitro apoptosis and the in vivo observed drop of CD4 T cells
in patients.
We
have spent a lot of time trying to find the origin of this massive
apoptosis, without finding a completely satisfactory explanation: the
most likely is the intensive oxidative stress existing in patients
since the beginning of their infection. This is also a finding I am
very proud of: although oxidative stress has been ’Äì and still is ’Äì
completely overlooked by AIDS researchers, it is likely to aggravate
the wrong activation of the immune system at the origin of its decline
and also it triggers inflammation through the production of cytokines.
Of
course, the next question arises: what are the factors causing
oxidative stress: viral proteins, fragments of viral DNA, co-infection
with mycoplasmas? Even after 25 years, we still do not know the
complete answer. But the phenomenon does exist and needs to be treated,
while most AIDS clinicians do not care about it at all!
The
treatment by combined antiretroviral therapy has, without doubt,
changed the prognosis of this lethal disease, from a death sentence to
an almost "normal" life. However, the virus is still there, ready to
multiply when the treatment is interrupted, and not all HIV infected
patients in the developing world have access to it. And the epidemics
still kill 2’Äì3 million people each year. It is thus absolutely
necessary to resolve these problems. Basic research, as well as
clinical research, has to be continued.
In
addition, I realised in the 1990s that research should not only be
localised in the wealthy laboratories of the developed countries, but
also in southern countries where a lot of patients were suffering from
AIDS and many other diseases like tuberculosis and malaria.
Too
many examples showed that collaboration between northern and southern
research laboratories is unequal, the south providing serum samples to
be analysed in the north. This "safari" concept is wrong. There are now
many young researchers trained in northern laboratories who would like
to return to their own countries, but are prevented from doing so
because laboratories and adequate structures are missing. Moreover, one
has to be in the regions where disease proliferates to realise how
complex the reality is.
This
is why I joined with the former Director General of UNESCO, Federico
Mayor, in initiating a foundation aimed at creating centres for
research and prevention in African countries. Although the task was
difficult, this concept was met with enthusiasm from colleagues and
medical doctors and also found the support of governments, particularly
in Côte d'Ivoire and Cameroon.
I
wish that based on these pilot experiments, a whole network of similar
centres could cover all the countries of the developing world where the
populations are badly hit by epidemics.
Another
lesson I drew from my AIDS experience was the weakening effect of
oxidative stress on the immune system and its pro-inflammatory role in
many chronic diseases, such as Parkinson's, Alzheimer's and rheumatoid
arthritis: a likely consequence of chronic infections? Or both
consequence and cause? There are many questions, which can be resolved
only by hard work and innovative thinking. I hope to be able to
continue both.
From Les Prix Nobel. The Nobel Prizes 2008, Editor Karl Grandin, [Nobel Foundation], Stockholm, 2009
This
autobiography/biography was written at the time of the award and later
published in the book series Les Prix Nobel/Nobel Lectures. The
information is sometimes updated with an addendum submitted by the
Laureate. To cite this document, always state the source as shown above.
Copyright © The Nobel Foundation 2008