IMMUNOLOGY2026™ Conference Recordings For Attendees-CTLA-4 mediates oral immunotolerance against systemic allergic sensitization to environmental allergens

CTLA-4 mediates oral immunotolerance against systemic allergic sensitization to environmental allergens

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Video Summary

This talk examined how oral exposure to food antigens can prevent systemic allergic sensitization. Using mouse models inspired by the LEAP study, the speaker showed that feeding antigen before airway exposure suppressed peanut-specific IgE, IgG1, and anaphylaxis. Parabiosis experiments suggested this protection is transferable systemically. With an ovalbumin model, oral antigen produced antigen-specific tolerance: it blocked ovalbumin responses but not peanut responses. Mechanistically, oral tolerance reduced germinal center B cells and suppressed antigen-specific T follicular helper cells, while bulk Tregs and even TFRs were not required. Single-cell and flow analyses revealed CTLA4-high CD4 T cell populations, including FOXP3-positive and FOXP3-negative cells with an anergy-like phenotype. Blocking CTLA4 reversed tolerance, restoring IgE and partially restoring anaphylaxis. Overall, the study concludes that CTLA4-dependent, antigen-specific CD4 cells mediate oral immunotolerance against systemic allergic sensitization.

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Date April 17, 2026 4:45 PM - 5:00 PM

Room 205

Session Airway Hypersensitivity and Asthma

Speaker Mia Masuda

Track Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)

Year 2026

Keywords

oral tolerance

food antigens

allergic sensitization

CTLA4

peanut allergy

April 17, 2026 4:45 PM - 5:00 PM

205

Airway Hypersensitivity and Asthma

Mia Masuda

Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)

2026