Mimotopes of the disialoganglioside GD2 elicit anti-GD2 antibodies recognising GD2 on melanoma cells

12505 Background: The disialoganglioside GD2, a carbohydrate antigen, is expressed on all tumors of neuroectodermal origin, including melanoma, sarcoma, neuroblastoma and small cell lung cancer. Due to its specific expression on tumor surfaces, GD2 is an attractive target for immunotherapy. The mouse/human chimeric antibody form ch14.18 was already applied in melanoma and neuroblastoma trials as passive immunotherapy. We aimed to replace the poorly immunogenic ganglioside with highly immunogenic peptides, in order to establish an active immunotherapy. Methods: We used the ch14.18 antibody to select GD2 mimotopes. In the present study, two mimics of the ch14.18 epitope were chosen for immunogenicity evaluation. The mimics were coupled to KLH (keyhole limpet hemocyanin) in order make them more immunogenic. Three groups of BALB/c mice were immunized i.p with the mimotope conjugates (GRL-KLH or DGG-KLH), or the carrier protein KLH alone. Results: BALB/c mice immunized with the mimotope conjugates indeed showe...