Vaccination with an ISCOM-based tumor vaccine and a TLR ligand overcomes tumor-induced immune suppression and leads to the eradication of established pancreatic carcinomas

Introduction: Pancreatic carcinoma is associated with a poor prognosis and new therapies are warranted. Tumor vaccination aims at inducing cytotoxic T cells capable of killing tumors. However, immune responses are severely impaired in cancer patients. Overcoming immune suppression is a challenge for new generation tumor vaccines. Methods: An ISCOM vaccine containing the model antigen OVA was generated. Mice were challenged s.c. with OVA-expressing pancreatic carcinoma cells (Panc02-OVA) either after (prophylactic) or before (therapeutic) vaccination with OVA/ISCOM alone or in combination with the TLR9 ligand CpG…