Related Experiment Video
Updated: Sep 22, 2025
08:56
Characterization of Thymic Settling Progenitors in the Mouse Embryo Using In Vivo and In Vitro Assays
Published on: June 9, 2015
8.4K
Identification of fibroblast progenitors in the developing mouse thymus
Pedro Ferreirinha1,2, Ruben G R Pinheiro1,2,3, Jonathan J M Landry4
1Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135, Porto, Portugal.
Development (Cambridge, England)
|May 19, 2022
Summary
Researchers identified two thymic fibroblast subsets crucial for T-cell generation. CD140αβ+GP38+SCA-1- cells act as progenitors, differentiating into mature CD140αβ+GP38+SCA-1+ fibroblasts, with maturation influenced by thymic crosstalk.
Area of Science:
- Immunology
- Developmental Biology
- Cell Biology
Background:
- The thymus stroma is vital for T-cell generation, with mesenchymal cells playing a key regulatory role.
- While mesenchymal progenitors are presumed to exist in the postnatal thymus, their identity and homeostasis mechanisms remain unclear.
- Understanding thymic mesenchymal cell dynamics is crucial for comprehending T-cell development and immune function.
Purpose of the Study:
- To identify and characterize distinct thymic fibroblast subsets and their developmental trajectories.
- To elucidate the progenitor capacity of thymic mesenchymal cells and their contribution to the stroma.
- To investigate the factors influencing thymic fibroblast maturation and homeostasis in vivo.
Main Methods:
- Flow cytometry and cell sorting to isolate distinct thymic fibroblast populations based on surface markers (CD140αβ, GP38, SCA-1).
- Transcriptional profiling to analyze the molecular signatures of identified fibroblast subsets.
- Lineage tracing and in vitro thymic organoid culture to assess cell fate and differentiation potential.
- Analysis of fibroblast populations in genetically modified mouse models (Rag2-/-, Rag2-/-Il2rg-/-) to study in vivo development.
Main Results:
- Two novel thymic fibroblast subsets were identified: CD140αβ+GP38+SCA-1- and CD140αβ+GP38+SCA-1+.
- CD140αβ+GP38+SCA-1- cells were prevalent in embryonic thymus and showed progenitor activity, generating CD140αβ+GP38+SCA-1+ cells.
- CD140αβ+GP38+SCA-1+ cells emerged later, predominated in postnatal life, exhibited a mature transcriptional profile, and maintained their phenotype in organoids.
- Fibroblast maturation, particularly of the CD140αβ+GP38+SCA-1+ subset, was dependent on thymic crosstalk, as evidenced by reduced abundance in Rag2-/- and Rag2-/-Il2rg-/- thymi.
Conclusions:
- CD140αβ+GP38+SCA-1- cells represent a source of thymic fibroblast progenitors.
- SCA-1 serves as a marker for distinct developmental stages of thymic fibroblast differentiation.
- Thymic fibroblast homeostasis and maturation are regulated by intercellular communication within the thymic microenvironment, highlighting the importance of thymic crosstalk for immune development.
