Comparison of the deletion of αβ TCR transgenic DP thymocytes induced by different APC from BALB.D2 or BALB/c mice. CD4 versus CD8 expression in R1 of control viable αβ TCR transgenic thymocytes cultured for 36 hours or 60 hours alone or with splenic DC and B cells from BALB.D2 or BALB/c mice. The percentage of CD4^high SP thymocytes (H) at 36 hours and 60 hours was 63% and 75%, respectively with BALB.D2 splenic DC, and 8% and 35% with BALB.D2 splenic B cells. The absolute number of DP and SP thymocytes has been obtained by multiplying the total number of cells per well by the percentage of viable cells, and by the percentage of each thymocyte subset calculated within the total viable cell population. The percentages shown correspond to corrected values, which have been calculated considering DP plus CD4⁺SP plus CD8⁺SP equals 100%, ie, excluding DC or B cells and DN thymocytes. The experiment shown is representative of a series of four experiments with similar results.