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Controlling pruritus in Atopic Dermatitis via AhR pathway – Webinar 28 February



This exciting research on microbial derivatives for managing the symptoms of Atopic Dermatitis was a Top 10 Poster from the IFSCC Barcelona Congress so we are delighted to have Samira Tamoutounour (L’Oréal) present her work in our next webinar on 28 February.


Commensal metabolites are promising tools to alleviate compromised skin such as atopic dermatitis (AD) with molecules naturally present at the skin surface and participating in the skin/commensal symbiosis. Indole-3-carboxaldehyde (IAlD) is a commensal microbial metabolite derived from tryptophan and proposed as a potential natural molecule for decreasing pruritus through the inhibition of Thymic Stromal Lymphopoietin (TSLP) production and subsequently type 2 immune responses. This mechanism is supposedly dependent on Aryl Hydrocarbon Receptor (AhR). However, activation of AhR by its ligands can lead to adverse effects, notably by inducing AhR/CYp1a1 detoxification and Nrf2 antioxidant pathways. In our study, we investigated the capacity of IAlD analogs to decrease AD inflammation in in vitro models. We show that IALD analogs are low inducers of Nrf2 pathway, with variable effects on Cyp1a1. We characterize a group of Tryptophan derivatives as ‘low Cyp1a1 inducers’ that showed potential for topical application in AD to alleviate itch, without inducing adverse effects via AhR/Cyp1a1 pathway. We are further investigating the differential pathways induced by those two groups. These findings present new tryptophan derivatives derived from healthy skin microbiome with potential to manage AD symptoms and lay foundation for the development of next generation cosmetic solutions for healthier skin.

Wednesday 28 February
8h West Coast USA • 10h Mexico City, Chicago • 11h East Coast USA, Bogotá • 13h Sao Paolo • 16h London • 17h Central Europe, West Africa • 18h Tel Aviv, South Africa • 9h30 New Delhi • 0h Singapore / HK / China / Taipei
Thursday 29 February
1h Korea / Japan • 3h Melbourne • 5h Wellington

Samira Tamoutounour
is Scientist and Project Leader, Advanced Research, L’Oréal. Samira obtained a PhD in skin immunology at the University of Aix-Marseille in Dr Bernard Malissen’s team in 2013, where she studied the origin and function of dendritic cells and skin macrophages. She contributed to the discovery of a new resident skin monocyte population. In 2014, she joined Dr Yasmine Belkaid as a postdoctoral fellow at the National Institutes of Health (NIAID, USA). She was awarded with ARC and EMBO fellowships. Samira developed research projects on communication between immune cells, microbiota and skin and their consequences for skin health and immune defense. In that field, she contributed to major discoveries that have been published in leading scientific journals, notably how keratinocytes orchestrate lymphocytes responses to microbiota. Since 2019, Samira has been part of L’Oréal Advanced Research and contributes to research projects targeting interactions between the immune system and microbiota to address compromised skin.