MBD2 Regulates Th17 Cell Differentiation and Experimental Severe Asthma by Affecting IRF4 Expression

Area of Science:

• Immunology
• Epigenetics
• Respiratory Medicine

Background:

• Severe asthma involves Th17 cells, IL-17, and airway neutrophil infiltration.
• Increased Methyl-CpG binding domain protein 2 (MBD2) expression in CD4+ T cells is observed in asthma patients.
• The epigenetic regulation of MBD2 in severe asthma pathogenesis and CD4+ T cell differentiation remains unclear.

Purpose of the Study:

• To investigate the role of MBD2 epigenetic regulation in experimental severe asthma.
• To explore the relationship between MBD2, IRF4, and Th17 cell differentiation in severe asthma.

Main Methods:

• Establishment of a neutrophil-predominant severe asthma mouse model.
• Analysis of airway hyperresponsiveness, BALF neutrophil granulocyte (NEU) counts, and IL-17 levels.
• Assessment of MBD2 and IRF4 protein expression in lung and spleen cells.
• Gene manipulation (overexpression/silencing) of MBD2 and IRF4 to study their effects on Th17 cell differentiation and IL-17 secretion.

Main Results:

• The asthma model exhibited characteristic features: airway hyperresponsiveness, increased BALF NEU, elevated IL-17, and enhanced Th17 cell differentiation.
• MBD2 and IRF4 protein expression were upregulated in lung and spleen cells of the model.
• Modulating MBD2 or IRF4 expression significantly altered Th17 cell differentiation and IL-17 secretion.
• MBD2 influenced IRF4 expression, but IRF4 did not affect MBD2 expression, suggesting a unidirectional regulatory relationship.

Conclusions:

• MBD2 and IRF4 play crucial roles in the pathogenesis of severe asthma.
• Epigenetic regulation of MBD2 is implicated in Th17 cell differentiation and IL-17 production in severe asthma.
• These findings offer novel insights into the epigenetic mechanisms underlying severe asthma and suggest potential therapeutic targets.