T-cell activation by an alloantigen prevents tolerance induction.Anti-Gal response to PKM immunization in KO mice after adoptive transfer of 20 × 106 KO lymphocytes that included memory anti-Gal B cells and 2 × 106 WT lymphocytes from semiallogeneic F1 C57BL/6 x BALB/c (ie, H-2bxd) mice (▪), 2 × 106 WT lymphocyte from syngeneic C57BL/6 (ie H-2b) mice (○), or no WT lymphocytes (•). Note that the immune response to the alloantigen prevents tolerance induction by WT lymphocytes. Data shown are means ± SE (n = 4). Statistical analysis by Student t test indicated significant differences (P < .001) between groups (•) and (○) at all serum dilutions. Significant differences (P < .05) were found between groups (•) and (▪) at serum dilutions of 1:400 to 1:1600, but not at serum dilutions of 1:50 to 1:200.
