Tissue architecture dynamics underlying immune development and decline in the thymus

Area of Science:

• Immunology
• Aging Research
• Molecular Biology

Background:

• Adaptive immune function declines with age, a process linked to thymic involution.
• Understanding the structural and transcriptional changes in the aging thymus is crucial for addressing age-related immune dysfunction.

Purpose of the Study:

• To investigate the structural and transcriptional alterations in the aging mouse thymus.
• To identify mechanisms contributing to age-associated decline in adaptive immunity.

Main Methods:

• Utilized high-resolution spatial transcriptomics and T-cell receptor (TCR) sequencing.
• Analyzed 21 thymus samples across the lifespan of mice.

Main Results:

• Observed significant disruptions in thymic organization, including impaired T cell development and B cell aggregate formation.
• Documented age-related shifts in cell-cell interactions, such as increased antigen-presenting cells and a switch to suppressive macrophages, creating an immunosuppressive microenvironment.
• Identified aged thymus regions with diminished TCR diversity and altered gene expression profiles.

Conclusions:

• The aging thymus undergoes substantial structural and molecular changes that impair adaptive immunity.
• These findings provide a comprehensive reference for understanding age-related immune decline and suggest potential therapeutic targets.