Cellular and humoral immune responses to adenovirus and p53 protein antigens in patients following intratumoral injection of an adenovirus vector expressing wild-type p53 (Ad-p53)

The immune responses of 10 patients with advanced non-small cell lung cance r receiving monthly intratumoral injections of a recombinant adenovirus con taining human wild-type p53 (Ad-p53) to adenovirus and transgene antigens w ere studied. The predominate cellular and humoral immune responses as measu red by lymphocyte proliferation and neutralizing antibody (Ab) formation we re to adenovirus serotype 5 vector antigens, with increased responses in po sttreatment samples. Consistent alterations in posttreatment cellular and h umoral immune responses to p53 epitopes were not observed, and cytotoxic Ab s to human lung cancer cells were not generated. Patients in this study had evidence of an antitumoral effect of this treatment with prolonged tumor s tability or regression; however, neither Abs to p53 protein nor increased l ymphocyte proliferative responses to wild-type or mutant p53 peptides have been consistently detected.