The “Plant Allergens” research group, from the Polytechnical University of Madrid, led by Professor Araceli Díaz Perales, has described how damage in the skin activates inflammatory pathways which are essential to develop food allergies.
Although we sometimes think of our skin as a simple physical barrier which passively avoids the entry of external agents to our organism, the truth is that it is actually a very active organ with functions that go beyond being a mere observer. “Due to its great metabolic and immunologic activities, we thought that the skin might be at the origin of several inflammatory diseases with great impact in our society. Food allergy would be an example of these diseases, constituting a potentially lethal pathology which affects around 8% of children on industrialized countries”, affirms Prof. Araceli Díaz Perales, from the Department of Biotechnology and Plant Biology of the Polytechnical University of Madrid.
Using experimental mice, this group of researchers has demonstrated that causing prolonged stress over our skin induces important immunological changes. “When cutaneous damage is sustained through time, we start to detect signals associated to cellular stress in the skin of the mice, as for example the protein NLRP3”, says Diego Pazos Castro, the predoctoral researcher that signs as a first author in this work, which has been published on Scientific Reports. “When these stress signals are present, the skin becomes extremely sensitive to external stimuli. From then on, we are unable to discriminate between what is harmful and what is beneficial to us, and we start to detect everything as an enemy. At this moment, if our skin gets in contact with any food, it will try to defend itself against some of the proteins present on it, and food allergy will start to develop in our organism. This process by which a healthy person becomes an allergic one is called sensitization”, this researcher explains.
Understanding the molecular details of allergic sensitization is crucial to fight the disease, which is ranked among the 5 main chronic health problems of the Spanish population, according to the Spanish National Health System. “We believe that the results of this work are important from two different points of view”, affirms Dr. Jaime Tomé Amat, codirector of the research with Prof. Araceli Díaz Perales. “First: prevention, encouraging us to keep our skin healthy to avoid the development of allergy. It is important to understand that nowadays proteins from food origin are present in lots of hygiene products, which makes it extremely hard to totally avoid the exposure to allergenic sources. And secondly: treatment, since in the article we describe how the use of drugs to block NLRP3 can alleviate the symptoms related with food allergy in experimental animals”.
The authors warn, however, that many questions regarding allergic sensitization remain unanswered, and there is still a lot of work to do in the field. Besides, they say that the skin is only one of the organs that might be involved in the first steps of allergic sensitization, with other epithelia (such as the respiratory or the digestive ones) being also key players in the process when they are damaged or stressed. “Hence, it is vital to look after ourselves from every perspective possible. Besides keeping our skin healthy, it is also important to follow a balanced diet and protect ourselves from respiratory infections, so we can maintain our immune system regulated at all levels”, affirms the researcher Pazos Castro.
Pazos-Castro, D., Gonzalez-Klein, Z., Montalvo, A.Y., Hernandez-Ramirez, G., Romero-Sahagun, A., Esteban, V., Garrido-Arandia, M., Tome-Amat, J., Diaz-Perales, A. 2022. NLRP3 priming due to skin damage precedes LTP allergic sensitization in a mouse model. Scientific Reports 12, 3329. DOI: 10.1038/s41598-022-07421-y