IMMUNOLOGY2026™ Conference Recordings For Attendees-Crosstalk of the environment and the immune system - challenges and opportunities, Sponsored by the German Soc. For Immunol. (DGfl)-2

Crosstalk of the environment and the immune system - challenges and opportunities, Sponsored by the German Soc. For Immunol. (DGfl)-2

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Video Summary

Charlotte Esser opened by introducing the German Society of Immunology and the symposium’s “One Health” theme, emphasizing how environment, lifestyle, climate, and microbes all shape immunity. Because two speakers were absent due to airline strikes, Petra Bacher presented her work on how fungi and food-related yeasts influence CD4 T cell responses, especially in inflammatory bowel disease (IBD).<br /><br />Bacher described an antigen-reactive T cell enrichment method used to identify rare microbe-specific T cells. Her lab found that while bacteria produced little difference between healthy donors and IBD patients, fungi elicited striking responses. In Crohn’s disease, especially ASCA-positive patients, there was strong T cell reactivity to yeasts such as Saccharomyces cerevisiae and Candida species. These responses were cross-reactive, clonally expanded, and often had a Th1/cytotoxic phenotype, including granzyme and perforin expression. Food-derived yeasts, including those in cheese, could also reactivate these cells.<br /><br />In contrast, Candida albicans induced a separate, homeostatic Th17 response focused on proteins in extracellular vesicles. These Th17 cells were largely CLA-positive, suggesting oral rather than gut priming, and shared clonotypes between oral and intestinal tissues. In Crohn’s disease, these pre-existing Candida-specific Th17 cells expanded, migrated to inflamed gut tissue, and acquired more pathogenic features. Overall, the talk showed that fungi can drive both beneficial and pathogenic immune responses in humans.

Meta Tag

Date April 16, 2026 4:15 PM - 5:15 PM

Room 104C

Session Crosstalk of the environment and the immune system - challenges and opportunities, Sponsored by the German Soc. For Immunol. (DGfl)

Speaker Petra Bacher

Track Mucosal And Regional Immunology (MUC)

Year 2026

Keywords

German Society of Immunology

One Health

fungal immunity

CD4 T cells

inflammatory bowel disease

Crohn's disease

Candida albicans

Saccharomyces cerevisiae

April 16, 2026 4:15 PM - 5:15 PM

104C

Crosstalk of the environment and the immune system - challenges and opportunities, Sponsored by the German Soc. For Immunol. (DGfl)

Petra Bacher

Mucosal And Regional Immunology (MUC)

2026