Immunization with multiple antigenic glycopeptide (MAG):Tn-poliovirus (PV)in the absence of adjuvant induces a potent antitumoral antibody response. BALB/c mice were immunized subcutaneously on days 0, 21, 42, and 63 with MAG:Tn3-PV, MAG:Tn3-PV with alum, or alum with unmethylated cytosine-phosphate-guanosine as adjuvant (4 mice per group). Control mice received only alum. (A) Mice were bled on days 20, 28, 49 and 70 to determine anti-Tn IgG antibody content in sera by enzyme-linked immunosorbent assay. Antibody isotypes were analyzed by enzyme-linked immunosorbent assay (B). Antitumor IgG titers were assessed at day 70 on Tn⁺ Jurkat and MCF 7 cells (C; FACS-Aria II, BD Biosciences). Data are expressed as mean ± SEM titers.