Figure 1.

Dose-dependent induction of TEa cell hyporesponsiveness. (a) Primary challenge. Viable TEa cells obtained from early frozen stocks of in vitro cultures, were stimulated with the indicated concentrations of spEa in the presence of a 5 : 1 ratio of splenocytes to transgenic cells. After a variety of empirical observations, we chose these conditions because they adequately display both the effect of antigen dose and ratio of TEa cells to APC on the phenotype described in this report. At daily intervals after stimulation, viable cell counts were determined and the data plotted as the mean values of five or more experiment ± SD. (b) secondary challenge. Viable TEa cells, recovered from day 7 after the primary challenge step, were restimulated with 1 µg/ml of spEa in the presence of a 5 : 1 ratio of splenocytes to transgenic cells. At each 24-hr interval after stimulation, the total number of viable cells were determined and represented as the mean values of five or more experiments ± SD.