Rag1-based time-stamp tracing of T-cell developmental origins

Area of Science:

• Immunology
• Developmental Biology
• Genetics

Background:

• The postnatal T-cell pool contains cells in various developmental stages, making it difficult to study T-cell differentiation and maturation.
• Understanding T-cell development is crucial for immunology and treating immune-related disorders.

Purpose of the Study:

• To develop a novel genetic strategy for time-resolved tracking of T-cell developmental origins.
• To apply this method to investigate the complex development of thymic regulatory T (Treg) cells.

Main Methods:

• Rag1-mediated time-stamp tracing, a genetic strategy for temporal tracking of T-cell development.
• Validation across flow cytometry, imaging, and single-cell multiomics.
• Application to thymic regulatory T (Treg) cell development.

Main Results:

• Time-stamp tracing successfully resolved distinct phases of Treg cell induction, maturation, and adaptation.
• Identified precursor populations for thymic Treg cell induction.
• Uncovered a maturation program in Treg cells marked by CD73 upregulation and DNA hypomethylation.
• Distinguished long-lived mature Treg cells based on activation and clonal expansion.

Conclusions:

• Rag1-based time-stamp tracing is a versatile and unbiased approach for studying T-cell developmental origins.
• This method provides new insights into the heterogeneity and developmental trajectories of thymic Treg cells.
• The findings advance our understanding of T-cell differentiation and adaptation in immunological contexts.