Reproducible procedures for establishing mouse thymic stromal cell lines

Area of Science:

• Immunology
• Developmental Biology
• Cell Biology

Background:

• Thymic epithelial cells (TEC) are crucial for T-cell development.
• Establishing functional TEC lines is vital for studying intrathymic T-cell maturation.
• Fetal thymus offers a unique model for understanding early T-cell progenitor interactions.

Purpose of the Study:

• To develop novel protocols for establishing mouse thymic epithelial cell lines (MTEC).
• To characterize the interaction of fetal thymocytes with different TEC populations.
• To investigate the potential role of specific TEC subsets in T-cell progenitor colonization and proliferation.

Main Methods:

• Two novel protocols were employed to isolate and establish MTEC from fetal thymus.
• TEC selection involved complex formation with thymocytes using viral vectors or Ca(2+)-free medium.
• Characterization of TEC-thymocyte interactions included binding, infiltration, and proliferation assays.

Main Results:

• Established MTEC lines formed distinct thymic epithelial clusters.
• NCAM(high) LFA-1(low) TEC clusters facilitated significant fetal thymocyte infiltration, colonization, and proliferation.
• NCAM(low) LFA-1(high) TEC and NCAM-negative fibroblast clusters showed limited or no thymocyte interaction.

Conclusions:

• NCAM-positive TEC lines, likely originating from the thymus cortex, support pro-T cell development.
• These TEC lines are valuable tools for studying intrathymic migration and clonal growth of T-cell progenitors.
• The findings provide insights into the cellular mechanisms governing early T-cell development in the fetal thymus.