Aire.

Area of Science:

• Immunology
• Genetics
• Molecular Biology

Background:

• Mutations in the autoimmune regulator (Aire) gene lead to autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), a monogenic autoimmune disease.
• Aire is crucial for central immune tolerance, primarily functioning within the thymus to eliminate self-reactive T cells.
• Aire promotes the ectopic expression of peripheral tissue-specific antigens in thymic medullary epithelial cells.

Purpose of the Study:

• To elucidate the molecular mechanisms underlying Aire's function in T cell tolerance and autoimmune disease pathogenesis.
• To investigate the unique characteristics of Aire-mediated transcriptional regulation.
• To explore Aire's role in thymic epithelial cell maturation and antigen cross-presentation.

Main Methods:

• Utilized animal models of APECED to study Aire's function in vivo.
• Conducted structure/function analyses of the Aire protein.
• Identified Aire's interaction partners to understand its molecular targets and mechanisms.

Main Results:

• Aire deficiency impairs clonal deletion of self-reactive thymocytes, leading to autoimmune attack on peripheral organs.
• Aire acts as a proapoptotic factor in thymic medullary epithelial cells, potentially facilitating antigen cross-presentation.
• Aire-mediated transcriptional regulation is characterized by broad, context-dependent, probabilistic, and noisy expression patterns.

Conclusions:

• Aire is essential for establishing central T cell tolerance by inducing the expression of a wide range of self-antigens in the thymus.
• Dysfunctional Aire leads to the escape of self-reactive T cells, resulting in autoimmune diseases like APECED.
• Aire's multifaceted role in transcription, apoptosis, and antigen presentation highlights its complex function in immune homeostasis.