New potential approach to treat atopic dermatitis

New potential approach to treat atopic dermatitis
Back with atopic dermatitis. Credit: Dermatologische Klinik, USZ

How does the immune system respond to fungi on our skin? Researchers at the University of Zurich have demonstrated that the same immune cells that protect us against skin fungi also encourage the inflammatory symptoms of atopic dermatitis. An antibody therapy could alleviate this chronic inflammatory skin disease.

The skin of humans and animals is densely populated by fungi. It is suspected that a small yeast species called Malassezia, which besides bacteria and viruses is part of the microflora of healthy skin, strengthens the body's defenses and prepares the immune system for dangerous pathogens, much like certain bacteria do. However, little is known about the that keep the ubiquitous fungus in check.

Immunologists at the University of Zurich have now shown that the immune system is responsible for maintaining the balance on our skin. The researchers were able to demonstrate that in mice as well as in humans, Malassezia fungi stimulate the immune system to produce the cytokine interleukin-17. "If this cytokine isn't released or if the that produce interleukin-17 are missing, there is nothing to stop the fungus from growing and infesting the skin," explains Salomé LeibundGut-Landmann, professor of immunology and head of the immunology section at the Vetsuisse Faculty of UZH.

Fungus can encourage skin allergy

But what happens when the balance between the fungus and the immune system on the surface of our body is lost? There is some evidence that the usually harmless Malassezia fungus plays a role in atopic dermatitis. In this chronic inflammatory skin allergy, which affects up to 20 percent of children and 10 percent of adults, the immune system overreacts to antigens from the environment, for example, house dust mites. This can lead to eczema, which is characterized by dry, inflamed skin lesions, typically appearing on the neck, forearms and legs. It is also one of the most common skin diseases in dogs.

The current study confirms that interleukin-17 production by certain immune cells, which normally provide protection against uncontrolled fungal growth on the skin, also contribute to the development of symptoms characteristic for atopic dermatitis. The fungus becomes an allergen on the skin, so to speak, and triggers an overreaction of the with the respective inflammatory characteristics. This finding is supported by experiments with cells from atopic dermatitis patients carried out in cooperation with the University Hospital Zurich and ETH Zurich.

Treatment with therapeutic antibodies

"The findings of our study suggest that that neutralize the effect of interleukin-17 could be an for atopic dermatitis. These antibodies already exist and are being used to treat psoriasis with great success," says LeibundGut-Landmann.

However, it remains to be studied why the against the Malassezia fungus can become pathological and why the normally protective mechanisms break down in atopic dermatitis patients.


Explore further

Scientists identify unique subtype of eczema linked to food allergy

More information: Florian Sparber et al, The Skin Commensal Yeast Malassezia Triggers a Type 17 Response that Coordinates Anti-fungal Immunity and Exacerbates Skin Inflammation, Cell Host & Microbe (2019). DOI: 10.1016/j.chom.2019.02.002
Journal information: Cell Host & Microbe

Citation: New potential approach to treat atopic dermatitis (2019, March 19) retrieved 18 July 2019 from https://medicalxpress.com/news/2019-03-potential-approach-atopic-dermatitis.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
1 shares

Feedback to editors

User comments

Mar 19, 2019
So the reigning thought is a fungus invades the skin, as whereas previously it had not, and there is no thought as to the probability of an organism piercing the skin, and in the process introducing a fungus ( and likely a bacterial ) entity access....????? Does this seem unlikely to anyone???

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more