K^b-tolerant Des-TCR CD8 T cells divide after transfer into lymphopenic mice. (A) CSFE-labeled splenocytes (2 × 10⁶) from thymectomized Des-TCR × 2.4KerIV-K^b.RAG2^−/− mice (tolerant) and thymectomized Des-TCR.RAG2^−/− mice (reactive) were transferred intravenously into RAG2^−/− mice, CBA mice, as well as irradiated CBA mice (6 Gy, 1 day before transfer). At the indicated time points, host splenocytes (n > 4 per time point) were analyzed by flow cytometry. Shown are relative log fluorescence intensities for CFSE after gating on Des-TCR CD8 cells. (B) The absolute number of Des-TCR CD8 T cells was determined 12 days after transfer into RAG2^−/− mice. (C) The indicated surface marker expression level on Des-TCR CD8 T cells was determined by flow cytometry before (thin line) and 10 days after (bold line) transfer of 2 × 10⁶ splenocytes from thymectomized Des-TCR × 2.4KerIV-K^b.RAG2^−/− (tolerant) and thymectomized Des-TCR.RAG2^−/− mice (reactive) into RAG2^−/− mice. Specificity of antibody staining was verified with the respective isotype-matched control antibody. Shown are relative log fluorescence intensities for the indicted cell surface molecules. Representative data from 2 to 4 independent experiments are shown (5 to 8 mice per group in total).