It is already well known that when a mother undergoes inflammation during pregnancy, her child is more likely to develop allergic diseases. Recently, a KAIST research team has become the first in the world to discover that inflammation within the placenta affects the fetus immune system, leading to the child with excessive allergic reactions after birth. This study presents a new possibility for the early prediction and prevention of allergic diseases such as pediatric asthma.
KAIST (President Kwang Hyung Lee) announced on August 4 that a research team led by Professor Heung-Kyu Lee of the Department of Biological Sciences found that inflammation occurred during pregnancy affects the system of regulating the response to the stress of the fetus through the placenta. Consequently, the survival and differentiation of the memory of T cells (key cells of the adaptive immune system) increase, which can cause stronger allergic reactions in children after birth.
The research team proved it by experiences on mice that have undergone excessive inflammation induced during pregnancy. First, they injected the LPS of the toxin component (lipopolysaccharide), a substance known to be a representative material which induces an inflammatory response in the immune system, in mice to cause an inflammatory response in their bodies, which also caused inflammation in the placenta.
It has been confirmed that the placental fabric, due to the inflammatory response, has increased a signaling substance called “tumor-alpha necrosis factor (TNF-α) ‘and this substance activated the immune cells called” neutrophils *’ ‘, causing inflammatory placenta damage. * Neutrophils: The most abundant type of white blood cells in our body (40-75%), playing an important role in innate immunity and killing bacteria and invading fungi.
These damage modulated the response to stress of postnatal offspring, leading to a large secretion of stress hormone (glucocorticoids). Consequently, the T cells of offspring, which are responsible for immune memory, survived longer and had stronger memory functions.
In particular, T Memory T cells created by this process caused excessive allergic reactions when they are exposed several times to antigens after birth. More specifically, when “allergens” of the dust of the house were exposed to the respiratory tract of the mice, a strong eosinophilic inflammatory response and excessive immune activation were observed, with an increase in immune cells significant for allergy and asthma reactions.
This study is the first in the world to identify how the inflammatory response of a mother during pregnancy affects the allergic immune system of the fetus through the placenta. “He added:” It will be an important scientific basis for developing biomarkers for early prediction and the establishment of prevention strategies for pediatric allergic diseases. “”
Professor Heung Kyu Lee
The first author of this study is Dr. Myeong Seung Kwon of the Kaist Graduate School of Medical Science (currently clinical stock market in gynecological oncology in the Department of Obstetrics and Gynecology of the Konyang University Hospital, and the results of the research were published in July 1 in the field of mucous immunology, “Mucosal Immunology” Paper: The memory formation of the placental T cells has been directed by inflammation promotes allergic responses in offspring via endogenous glucocorticoids ※ Doi: https://doi.org/10.1016/j.mummm.2025.06.006
This research was carried out as part of the fundamental scientific research program and the bio-drug technology development program supported by the Ministry of Science and ICT and the National Research Foundation of Korea.