Germline hypomorphic CARD11 mutations in severe atopic disease

Area of Science:

• Immunology
• Genetics
• Dermatology

Background:

• Severe atopic dermatitis often lacks identified genetic causes.
• Understanding monogenic factors is key to unraveling complex allergic diseases.

Purpose of the Study:

• To identify genetic underpinnings of severe atopic dermatitis.
• To investigate the functional impact of novel CARD11 mutations on immune cell function.

Main Methods:

• Next-generation sequencing was used to analyze patients with severe atopic dermatitis.
• Functional assays were performed on T cell lines with mutant CARD11 constructs.
• Immune cell function, including cytokine production and signaling pathways, was assessed.

Main Results:

• Novel heterozygous CARD11 mutations were found in eight individuals from four families.
• Mutant CARD11 exhibited loss-of-function and dominant-interfering activity in T cell signaling.
• Patient T cells showed impaired nuclear factor-κB and mTORC1 activation, and reduced interferon-γ production.
• Glutamine supplementation partially rescued mTORC1 and interferon-γ defects.

Conclusions:

• Hypomorphic CARD11 mutations can cause severe atopic dermatitis through cellular defects.
• These defects involve impaired lymphocyte signaling and cytokine production.
• The findings suggest potential therapeutic strategies targeting CARD11 function or related metabolic pathways.