Immunotherapy using allogeneic squamous cell tumor-dendritic cell fusion hybrids.

BACKGROUND Tumor-associated antigens (TAAs) are known to be immunotherapy targets; thus tumor-sharing TAA may be used as a fusion hybrid partner to confer protection against subsequent tumor challenge. METHODS The squamous cell carcinomas (SCCs), SCCVII and B4B8, were used in C3H/HEN mice: SCCVII (H-2(k)) is syngeneic, B4B8 (H-2(d)) is allogeneic. Experiments using tumor alone included hyperimmunization schedule, subdermal and intranodal routes. Mice were challenged 2 weeks later. Fusion hybrids were created from both SCC tumor cell lines and syngeneic dendritic cells (DCs). These were delivered intranodally for immunization, and mice were challenged with tumor 2 weeks later. RESULTS Only syngeneic tumor given subdermally was able to protect after tumor challenge 2 weeks later. Hyperimmunization schedule did not alter these findings. However, fusion hybrid immunization from both allogeneic and syngeneic SCCs conferred protection after tumor challenge. CONCLUSIONS Allogeneic tumor-DC fusion hybrids targeting TAA can protect against subsequent tumor challenge.