Impaired interferon response in plasmacytoid dendritic cells from children with persistent wheeze

Area of Science:

• Immunology
• Pediatric Allergy and Pulmonology
• Virology

Background:

• Impaired interferon responses and allergic sensitization are implicated in virus-induced wheeze and asthma in children.
• Plasmacytoid dendritic cells (pDCs) are crucial for antiviral immunity via type I interferon production.
• pDCs express the high-affinity IgE receptor, which can downregulate interferon production, potentially linking allergic sensitization to impaired antiviral defense.

Purpose of the Study:

• To investigate the phenotype and function of circulating pDCs in children with a defined longitudinal wheezing pattern.
• To explore the association between pDC characteristics and recurrent wheezing episodes in early childhood.

Main Methods:

• Multiparameter flow cytometry was used to analyze peripheral blood mononuclear cells (PBMCs) from 38 children with acute wheeze and 19 controls.
• RNA sequencing was performed on isolated pDCs to assess their transcriptomic profile.
• Longitudinal exacerbation phenotypes were determined using hospital databases.

Main Results:

• Children with persistent wheezing phenotypes exhibited a significant depletion of circulating pDCs.
• These children also showed increased expression of the FcεRI (high-affinity IgE receptor) on their pDCs.
• Transcriptomic analysis revealed that pDCs from children with persistent wheezing did not mount a robust antiviral response compared to those with non-recurrent wheezing.

Conclusions:

• Circulating pDC phenotype and function are altered in young children experiencing persistent wheezing.
• Increased high-affinity IgE receptor expression on pDCs correlates with impaired interferon production during acute wheezing exacerbations.
• These findings suggest a potential mechanism linking allergic sensitization and impaired antiviral immunity in the development of persistent childhood wheeze and asthma.