DOK3 promotes atopic dermatitis by enabling the phosphatase PP4C to inhibit the T cell signaling mediator CARD11

Area of Science:

• Immunology
• Dermatology
• Molecular Biology

Background:

• CARD11 scaffolding protein is crucial for lymphocyte antigen receptor signaling.
• CARD11 mutations link to atopic dermatitis with impaired T cell signaling and type 2 helper T cell skewing.

Purpose of the Study:

• To investigate the role of docking protein DOK3 in atopic dermatitis pathogenesis.
• To elucidate the mechanism by which DOK3 influences CARD11 activity and T cell signaling.

Main Methods:

• Studied DOK3-CARD11 interaction and DOK3's effect on CARD11 phosphorylation in T cells.
• Utilized knockout mouse models to assess the impact of Dok3 deletion on T cell function and skin inflammation.
• Analyzed DOK3 and IFNG expression in T cells from atopic dermatitis patients.

Main Results:

• DOK3 suppresses CARD11 activity by recruiting protein phosphatase 4, dampening downstream signaling.
• Dok3 knockout enhanced T cell IFN-γ production and protected against experimental atopic dermatitis.
• Increased DOK3 expression and decreased IFNG expression were observed in T cells from atopic dermatitis patients.
• Certain CARD11 mutations in patients showed stronger binding to DOK3.

Conclusions:

• DOK3 plays a key role in atopic dermatitis by inhibiting CARD11 signaling.
• The strength of DOK3-CARD11 interaction may predispose individuals to atopic dermatitis.
• Targeting DOK3 could be a potential therapeutic strategy for atopic dermatitis.