Figure 3.

2C-TCR⁺ CD8⁺ T cells from class I⁺ into β₂m^−/− chimeras respond to antigen-mediated stimulation. T cells from C57BL/6, 2C-TCR I⁺, or β₂m^−/− mice and from the various 2C-TCR⁺ fetal liver chimeras were stimulated with B10.D2 spleen cells, expressing the L^d alloantigen for the 2C-TCR, or with negative control C57BL/6 spleen cells. Samples of each cell preparation also were stimulated with Con A to assess mitogen responsiveness. The proportion of 1B2⁺ and 1B2⁺ CD8⁺ T cells in each cell preparation before stimulation is given above each set of columns. The Con A responses of the cells from 2C β₂m^−/− mice and 2C β₂m^−/− into β₂m^−/− chimeras probably is mediated by 2C-TCR⁺ CD4⁻CD8⁻ cells, which fail to respond to L^d but can respond to more potent stimuli (22). The experiment was repeated once with similar results.