Tumors adapt rapidly to thwart vaccine-induced T cell attack but this adaptive response can be overcome by manipulation of costimulation and immune checkpoints (48.30)

Abstract We have developed a prototypic recombinant adenovirus vaccine encoding dopachrome tautomerase (rHuAd5-hDCT) that leads to moderate suppression of B16F10 melanoma growth through a CD8+ T cell- and IFN-γ-dependent mechanism. The immunogenicity of rHuAd5-hDCT was improved by concomitant 4-1BB stimulation leading to enhanced control of tumor growth; however, most tumors ultimately relapsed. Gene expression analysis revealed a rapid …