Immune Cell–Mediated Antitumor Activities of GD2- Targeted Liposomal c-myb Antisense Oligonucleotides Containing CpG Motifs

neuroblastoma, the most common extracranial solid tumor of infancy, is linked with cell proliferation and differentia-tion. Neuroblastoma can be selectively targeted via mono-clonal antibodies against the disialoganglioside (GD2) tumor-associated antigen. Liposomes coated with anti-GD2 antibodies (targeted liposomes) and entrapping a c-myb antisense oligonucleotide have antitumor activity. Because antisense oligonucleotides containing CpG motifs can stim-ulate immune responses, we evaluated the effect of CpG-containing c-myb antisense oligonucleotides encapsulated within targeted liposomes. Methods: Antisense (myb-as) and scrambled (myb-scr) control oligonucleotides with CpG mo-tifs were encapsulated within GD2-targeted and non-targeted liposomes. Two murine (nude and SCID-bg) xeno-graft models of neuroblastoma were established. Mic