For more information contact:
Catherine Baldwin at Scientext
(800) 960-2559
[email protected]
VACCINE COULD PREVENT ASTHMA
Albuquerque, N.M., August 1, 1997 -- A New Mexico respiratory
scientist says that some forms of asthma may be eradicated just as
polio and measles were: by immunizing children with a vaccine.
Under the Lovelace Respiratory Research Institute's patent pending
technology, immunologist David Bice, PhD has new research results
suggesting that exposing children's lungs to substances that cause a
specific immune response in the lungs may protect them from developing
asthma.
While the idea of immunization against disease is not a new one, Dr.
Bice's concept of producing immune responses in the lung that might
prevent asthma is a significant and controversial departure from
current theories in asthma research. Some researchers suggest that
environmental exposures may be important in the cause of allergic
disease. They infer that increasing allergic disease in our society
could be the result of increasing pollution. However, recent studies
of children living in areas of industrial pollution showed that they
actually have fewer cases of asthma than children living in areas with
less pollution do. Other research has focused on asthma as a
genetically inherited disease, but not all children whose parents or
grandparents suffer from asthma have asthma themselves.
Regardless of what they believe the cause of asthma is, there has been
no clear explanation for why one individual has asthma with allergic
responses in the lungs while another individual has hay fever with
allergic responses in their nasal airways. Dr. Bice's research
supports the possibility that the immune responses that cause asthma
are localized in the lungs and nasal passages. If this concept is
correct, the lungs or nasal passages would be the source of the
antibody to allergens found in the rest of the body. Dr. Bice
describes the lungs and nose as "target organs" for allergic disease.
If allergic immune response is localized to "target organs," it may be
possible to produce a protective immune response in these "target
organs" during childhood to prevent the development of asthmatic and
other allergic immune responses. In effect, a child could be
vaccinated or "immunized" against asthma.
Background
Dr. Bice has hay fever. "Oh, it's really awful, " he says, "The runny
nose, the itchy eyes. . .the whole deal."
But Dr. Bice doesn't have asthma.
"It was really that puzzle of how you could have one but not the other
that led us to develop our hypothesis," says Bice.
Searching for how immunity is produced in the lung is what David Bice
has done for a living at Lovelace Respiratory Research Institute since 1975.
What Dr. Bice and his colleagues at the Institute found out may explain the
puzzle and provide a cure for asthma.
"Immunity" and asthma
Generally, we think of immunity as a positive, protective reaction of
the body. The human immune system responds to proteins on the surface
of a bacterium or a virus by producing antibodies against them.
Antibodies that are made can remain in the body for years, or even a
lifetime. The next time the body is exposed to the same bacteria, it
is recognized by the antibodies and eliminated, preventing illness.
The presence of the antibodies confers a protective "immunity" against
the bacteria. To "immunize" an individual is to expose them to the
proteins on the surface of an inactive or dead bacteria or virus.
Their immune system then produces antibodies to the specific bacteria
or virus and if they are subsequently infected with the live bacteria
or virus, their body can protect itself.
Research has shown that we all make antibodies to allergens. The type
of antibody produced in non-allergic people does not cause disease and
could be considered protective. However, the antibody made by people
with asthma, as well as hay fever, is a form of immunity that is not
protective. In some individuals, exposure to an allergen, like
pollen, causes them to produce a special "anti-allergen" antibody,
known as IgE. When these individuals are subsequently exposed to the
allergen, the anti-allergen antibody touches off a cascade of other
chemical signals that cause inflammation of the airways, sneezing,
runny nose, itchy eyes, and other symptoms. In the case of asthma,
the inflammation affects the airways leading into the lungs. The
airways tighten and constrict and fill with mucus, making it very
difficult to breathe. The result can be fatal.
In tests, researchers have found the anti-allergen antibody throughout
the body. Since the antibody is distributed so widely, scientists
have found it difficult to understand and treat allergic reactions
isolated to the nose or the lungs. One particularly baffling piece of
the puzzle is how the allergic response can be one place but not the
other. Many people suffer from hay fever, an allergic response in the
nose, but they have limited or no asthma in their lungs. And, some
people who have asthma don't have any hay fever. How could this be if
they have the same amount of anti-allergen antibody running around
their system?
Breakthrough Experiments
In a series of experiments, Dr. Bice demonstrated that immune
responses in the lung are very localized. He found that if he
introduced a substance that induces antibody production into a single
small airway, antibodies would be produced at that specific site for
up to five years. The same antibody would migrate into the blood, but
it was produced only at the site in the lung.
In another set of experiments, Dr. Bice found that if a lung was
stimulated to produce antibodies and then transplanted into a subject
that didn't have those antibodies, the transplanted lung would
continue to produce antibodies for over a year. These results were
consistent with a British study that showed if non-asthmatic
patients received a lung transplant from an asthmatic donor, they
would subsequently become asthmatic. These results show that while
the anti-allergen antibody is distributed throughout the body, it is
produced only in the "target organ."
"People with asthma or hay fever could have the same level of
anti-allergen antibody distributed throughout their bodies, but the
high concentration of anti-allergen antibody in their 'target organs'
would cause allergic responses in the lung or the nasal airways," says
Dr. Bice, "This would explain why it is possible for some people have
hay fever but not asthma, because the anti-allergen antibody is being
produced in their nose, but not their lungs."
How, then, could this lead to a cure for asthma?
"Understanding that the immune response causing asthma is coming from
the lung itself allows us to treat the lung directly," says Bice.
Current studies in Britain and Germany suggest that people whose lungs
are challenged by an infection early in life develop a protective
immune response in their lungs rather than an allergic immune response
and they don't develop asthma.
"If we can determine how to produce that protective immune response,
then it may be just a matter of immunizing children's lungs using an
inhaled aerosol to prevent them from developing asthma."
Bice says, using this new model for asthma, he will continue his work
to determine if it is possible to manipulate the development of immune
responses in the lung. He hopes to work with pharmaceutical companies
interested in testing new asthma drugs using the new model.
Lovelace Respiratory Research Institute
The Lovelace Respiratory Research Institute is a private biomedical
research institute dedicated to the reduction of the nation"šs
substantial respiratory health burden. The Institute brings a broad
range of research capabilities and research alliances to bear on
respiratory health issues of concern to government, industry,
universities, health advocacy organizations, and the public. The
Institute staff is committed to the cure of respiratory diseases
through research aimed at understanding their causes and biological
mechanisms, eliminating exposures to causal agents, and developing
improved treatments. With its diverse research capabilities, its
close working relationships with universities and other laboratories,
and its endowed research programs, it is one of the largest
independent, private biomedical research organizations and the
nation"šs only such organization wholly dedicated to basic research on
respiratory health problems.
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Interviews with Dr. Bice are available by appointment. For more
information, contact Catherine Baldwin at Scientext, 1-800-960-2559.
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