FOR IMMEDIATE RELEASE
Contact:
Donna Krupa
703.527.7357 (direct
dial)
703.967.2751 (cell) or
djkrupa1@aol.com
RESEARCHERS FIND A KEY TO IMMUNOLOGICAL DEVELOPMENT
PITTSBURGH, Pa. -- Children are born with the
ability to make antibodies, proteins that fight infection. However, they do
not respond to immunization in the same way as adults and several aspects of
the immune system are distinctly different. Researchers at the Oklahoma
Medical Research Foundation (OMRF) have found another difference, one that
may be important to development of the immune system during fetal life.
Lymphocytes, the cells responsible for making
antibodies, are made in large numbers throughout life within bone marrow. A
variety of evidence suggests that this process is regulated in a negative
way by hormones, including estrogen. When estrogen levels are high, as they
are during pregnancy, lymphocyte production is severely depressed in the
mother’s bone marrow. It has been a mystery why the high estrogen
concentrations do not also prevent development of the baby’s immune system.
Dr. Hidyea Igarashi and his colleagues at OMRF may have
solved this paradox. Estrogen controls lymphocyte formation, and thus
replenishment of the immune system by binding to hormone receptors found
only in rare “precursors” within adult bone marrow. Igarashi found that
the receptors were not expressed on corresponding cells of the fetus.
Indeed, the receptors are expressed after birth in experimental animals and
man. By lacking these receptors, the immune system of the fetus is
protected from estrogen and related compounds that might be present in the
environment. It adds to information that various kinds of “stem” cells may
not be the same in fetal and adult life.
Paul W. Kincade, Ph.D., the head of the research team,
will present detailed findings of this research, “Sex Steroids Regulate
Lymphocyte Development in Adults, but not Fetal Life and Can Be Used to
Resolve Early Blood Cell Precursors," at the upcoming conference, Genomes
and Hormones: An Integrative Approach to Gender Differences in Physiology.
The conference is being sponsored by the American Physiological Society (APS)
and will be held October 17-20, 2001, at the Westin Convention Center,
Pittsburgh, PA.
Other investigators in Dr. Kincade’s lab have found
that hormones can be used as experimental tools for understanding how the
various types of specialized blood cells are made from stem cells within
bone marrow. His research team’s efforts are supported by grants from the
National Institutes of Health (NIH).
-end-
The
American Physiological Society (APS) was founded in 1887 to foster basic and
applied science, much of it relating to human health. The Bethesda,
MD-based Society has more than 10,000 members and publishes 3,800 articles
in its 14 peer-reviewed journals every year.
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Editor’s Note: To receive a copy of the abstracts, to interview speakers or
for more information, contact Donna Krupa at 703.527.7357(direct dial),
703.967.2751 (cell) or djkrupa1@aol.com.
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