Allogeneic class I major histocompatibility complex gene transfer in murine neuroblastoma in vivo.

In vivo intratumoral gene transfer of allogeneic class I major histocompatibility complex (MHC) genes augments the immune response against weak tumor antigens. In this study, mice inoculated with the allogeneic MHC molecule (H-2Kb), had transduced-murine neuroblastoma C1300S3 cells showed prolonged survival relative to non-transduced or neo transduced tumors (p < 0.005). Interestingly, direct in vivo gene transfer of H-2Kb plasmid DNA complexed with HVJ-liposomes into S3 tumors was highly efficient, resulting in transduction of 8% of the interstitial cells within the tumor but rarely within tumor cells. Regression of established tumors and prolonged survival occurred in 50% of mice injected with H-2Kb, in contrast to no tumor regression in mice receiving control plasmid (p < 0.005). This study concludes that interstitial cells could serve as an important target of intratumoral gene transfer, and further that HVJ-liposome complexes could be a vehicle for in vivo gene transfer.