IMMUNOLOGY2026™ Conference Recordings For Attendees-Eosinophil Activation in the Allergic Lung Limits Pneumococcal Superinfection During Influenza

Eosinophil Activation in the Allergic Lung Limits Pneumococcal Superinfection During Influenza

Video Transcription

Video Summary

The speaker argues that eosinophils are crucial for lung host defense in three settings: allergic asthma, influenza, and pneumococcal pneumonia. Using mouse models, her team shows that allergic asthma can protect against influenza, reducing weight loss and lung damage without affecting viral replication. Eosinophils change after influenza infection: they degranulate, help neutralize virus, repair airway damage, and can even present viral antigens to CD8 T cells. Single-cell studies revealed distinct eosinophil subpopulations linked to allergy, infection, and tissue repair. In a three-hit model of asthma plus influenza plus bacterial pneumonia, eosinophils were also important for controlling pneumococcal infection. They rapidly engulf bacteria, kill them using granule proteins like major basic protein, and may present bacterial antigens to CD4 T cells. When eosinophils or their granule proteins were absent, disease worsened. Overall, eosinophils are presented as versatile immune “heroes” with roles in protection, repair, and communication with other lung immune cells.

Meta Tag

Date April 19, 2026 10:45 AM - 11:00 AM

Room 104 AB

Session Innate Defenses against Pathogens

Speaker Amali Samarasinghe

Track Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)

Year 2026

Keywords

eosinophils

allergic asthma

influenza

pneumococcal pneumonia

lung host defense

April 19, 2026 10:45 AM - 11:00 AM

104 AB

Innate Defenses against Pathogens

Amali Samarasinghe

Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)

2026