Fig. 1.

Expression of C3 transferase in the thymus of adult mice prevents up regulation of thymocyte developmental markers. (A) Data show flow cytometry analysis of CD4 and CD8 expression on Thy1⁺ thymocytes from CD2–C3, RAG2^−/− and C57BL/6 control mice. (B) Data show flow cytometry analysis of CD25 and CD44 expression on Thy1⁺ CD4⁻CD8⁻ thymocytes from CD2-C3, RAG2^−/− and C57BL/6 control mice. (C) Histograms show intracellular TCR-β staining in DN3 cells (CD44⁻CD25⁺ Thy1⁺ CD4⁻CD8⁻⁾ from wild type or CD2–C3 transferase mice. Isotype-matched control antibody shows negative staining (dotted line). In 5 experiments, TCR-β positive cells in wild type DN3s averaged 24% (range 20–25%) whereas in CD2–C3 DN3s averaged 10% (range 7.35–11.47%).