Age-Based Dynamics of a Stable Circulating Cd8 T Cell Repertoire Component

Area of Science:

• Immunology
• T-cell biology
• Systems immunology

Background:

• T-cell memory is crucial for adaptive immunity, shaped by pathogen exposure.
• Understanding the quantitative dynamics and stability of T-cell repertoires is key to deciphering immune memory.
• Previous studies indicated a complex distribution in antigen-experienced CD8 T cells.

Purpose of the Study:

• To quantitatively analyze CD8 T-cell repertoires using a rank-frequency approach.
• To investigate the stability and dynamics of T-cell repertoires in relation to clonotype distribution.
• To examine temporal repertoire dynamics across different age groups.

Main Methods:

• Quantitative analysis of CD8 T-cell repertoires using a rank-frequency approach.
• Assessment of clonotype stability and its correlation with rank frequency.
• Temporal analysis of influenza-specific T cells in children, middle-aged, and older adults.

Main Results:

• CD8 T-cell repertoires exhibit a complex two-component distribution, also observed in BV19+ T cells.
• An inverse correlation exists between clonotype rank frequency and stability, with stable clonotypes forming the second component.
• Temporal dynamics reveal system development, aging, increasing complexity, a stable circulating component, and eventual loss of complexity and stability.

Conclusions:

• The circulating T-cell repertoire acts as a depot for stable, selected clonotypes.
• T-cell repertoire dynamics demonstrate a process of development, maturation, and aging.
• Immune memory complexity and stability change over time and with age.