Allergic sensitization impairs lung resident memory CD8 T-cell response and virus clearance

Area of Science:

• Immunology
• Respiratory Medicine
• Allergy

Background:

• Asthma patients frequently experience respiratory viral infections and impaired virus clearance.
• Lung-resident memory T cells are crucial for rapid antiviral defense.
• The lung microenvironment influences the development of these memory T cells.

Purpose of the Study:

• To investigate how allergen sensitization affects the development of virus-specific lung-resident memory T cells.
• To determine the impact of allergen sensitization on viral clearance in the lungs.
• To explore the relationship between immune signatures and exacerbations in asthma patients.

Main Methods:

• Mice were sensitized with house dust mite extract, followed by influenza virus challenge.
• Antiviral T-cell responses and viral loads were assessed.
• Gene set variation analysis was performed on data from the U-BIOPRED asthma cohort.

Main Results:

• Sensitized mice exhibited higher viral loads and reduced virus clearance after secondary infection.
• Allergen sensitization led to fewer antiviral lung-resident memory CD8 T cells and lower pulmonary IFN-γ levels.
• In asthma patients, enrichment of IFN-γ-induced genes correlated with resident memory T-cell signatures and fewer exacerbations.

Conclusions:

• The allergen-sensitized lung microenvironment hinders the formation of antiviral lung-resident memory CD8 T cells and impairs virus clearance.
• This defective antiviral memory response may contribute to increased viral exacerbations in asthma.
• Findings highlight a mechanism linking allergen exposure, impaired immunity, and asthma severity.