Kinetics of tolerance induction and ELISPOT in tolerized mice.(A) Production of anti-Gal in KO recipients of 20 × 106 lymphocytes that include memory anti-Gal B cells and 2 × 106 WT lymphocytes or no WT lymphocytes. The mice received the first of 2 PKM immunizations on days 1, 3, 10, or 14 after adoptive transfer. Anti-Gal was measured in serum samples diluted 1:100 in 5 mice in each group. (B) Analysis of lymphocytes secreting anti-Gal in tolerized or control KO mice, as measured by ELISPOT. Lymphocytes were obtained from KO recipients of 20 × 106 lymphocytes from PKM-immunized mice and 2 × 106 WT lymphocytes (○) or no WT lymphocytes (•). The mice were immunized with PKM on days 14 and 21 after adoptive transfer. ELISPOT assayed on day 28. Data shown are means ± SE (n = 5). Statistical analysis by Student t test indicated significant differences (P < .05) between the 2 groups at all lymphocyte concentrations.
