Researchers find a key to immunological development

October 18, 2001

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).
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.


Contact: Donna Krupa: 703.527.7357
Cell: 703.967.2751 or

APS Newsroom @
The Westin Convention Center
Pittsburgh, PA
October 17-20, 2001
Tel: 412.281.3700 (The Crawford Room)

American Physiological Society

Related Stem Cells Articles from Brightsurf:

SUTD researchers create heart cells from stem cells using 3D printing
SUTD researchers 3D printed a micro-scaled physical device to demonstrate a new level of control in the directed differentiation of stem cells, enhancing the production of cardiomyocytes.

More selective elimination of leukemia stem cells and blood stem cells
Hematopoietic stem cells from a healthy donor can help patients suffering from acute leukemia.

Computer simulations visualize how DNA is recognized to convert cells into stem cells
Researchers of the Hubrecht Institute (KNAW - The Netherlands) and the Max Planck Institute in Münster (Germany) have revealed how an essential protein helps to activate genomic DNA during the conversion of regular adult human cells into stem cells.

First events in stem cells becoming specialized cells needed for organ development
Cell biologists at the University of Toronto shed light on the very first step stem cells go through to turn into the specialized cells that make up organs.

Surprising research result: All immature cells can develop into stem cells
New sensational study conducted at the University of Copenhagen disproves traditional knowledge of stem cell development.

The development of brain stem cells into new nerve cells and why this can lead to cancer
Stem cells are true Jacks-of-all-trades of our bodies, as they can turn into the many different cell types of all organs.

Healthy blood stem cells have as many DNA mutations as leukemic cells
Researchers from the Princess Máxima Center for Pediatric Oncology have shown that the number of mutations in healthy and leukemic blood stem cells does not differ.

New method grows brain cells from stem cells quickly and efficiently
Researchers at Lund University in Sweden have developed a faster method to generate functional brain cells, called astrocytes, from embryonic stem cells.

NUS researchers confine mature cells to turn them into stem cells
Recent research led by Professor G.V. Shivashankar of the Mechanobiology Institute at the National University of Singapore and the FIRC Institute of Molecular Oncology in Italy, has revealed that mature cells can be reprogrammed into re-deployable stem cells without direct genetic modification -- by confining them to a defined geometric space for an extended period of time.

Researchers develop a new method for turning skin cells into pluripotent stem cells
Researchers at the University of Helsinki, Finland, and Karolinska Institutet, Sweden, have for the first time succeeded in converting human skin cells into pluripotent stem cells by activating the cell's own genes.

Read More: Stem Cells News and Stem Cells Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to