Fig. 4.

Anti-Tn antibodies induced in cancer patients by the MAG-Tn3 vaccine efficiently kill Tn⁺ Jurkat cells through complement-dependent cytotoxicity. Patients were immunized on days 0, 21, 42, 63, 84, and 105 with the MAG-Tn3 vaccine formulated with the immunostimulant AS15. Patients 01, 02, and 03 received intramuscular injections of 30 µg MAG-Tn3, whereas patients 04, 05, 06, and 07 received 100 µg MAG-Tn3. Pre- and post-immunization sera were analyzed for their ability to kill the Jurkat Tn⁺ human cell line. Tn⁺ Jurkat cells were incubated with immunoglobulins purified from the sera of patients at four concentrations (250, 125, 61, and 30 µg/mL) and complement. After 5 h, cell viability was measured using the Celltiter-Blue kit^® (Promega). The percentage of CDC was calculated as described in Materials and Methods and the results are expressed as the mean ± SD of four to six replicates from two to three independent experiments. The statistical significance of the differences was determined relative to baseline by the unpaired Student’s t test. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001