TCR Affinity for Self-Ligands Influences the Development and Function of Encephalitogenic T Cells
Figure 2
Development of OVαβ TCR expressing thymocytes.
The strong skewing of thymocytes expressing the high affinity MBPαβ TCR towards the CD4 lineage is not seen in OVαβTCR expressing mice. Expression of only the MBPβ chain does not markedly alter T cell development. (A) Single cell suspensions of thymocytes (top) and lymph node cells (bottom) from OVαβ, MBPαβ, MBPβ transgenic and transgene negative mice were stained with antibodies against CD4, CD8 and TCR Cβ. Only TCR Cβ+ cells are shown in the lymph node cell plots. The number indicates the percent of cells in the quadrant. Only subtle variations in the percent of cells within each quadrant were noted during repeat experiments. (B) CD4 SP thymocytes from OVαβ TCR transgenic mice express a high percentage of endogenous TCRα chains, whereas MBPαβ TCR transgenic mice predominantly express the transgene encoded Vα2 chain. Single cell suspensions of thymocytes from the indicated mouse strain were stained with antibodies against CD4, CD8 and individually with each of the four available TCR Vα specific antibodies. The percent of cells within the CD4 single positive population expressing each of the Vαs is shown. More than 1×106 events were collected per sample. One of two experiments is shown. Greater than 98% of T cells in the OVαβ, MBPαβ and MBPβ mice expressed the transgene encoded Vβ8.2 TCR. (C) Increased levels of proliferation in response to the Ac1-11 peptide indicate a substantial number of antigen specific T cells develop in the OVαβ mice. CD4 T cells were enriched by negative selection. Double cultures were set up with 2.5×104 CD4+ T cells and 1×105 T cell depleted, irradiated B10.PL splenocytes plus the indicated amount of the MBP Ac1-11 peptide. Assays were pulsed with 3[H]thymidine after 48 hours and harvested after an additional 24 hours. Each condition was set up in triplicate and data was averaged. One example of three experiments is shown.