A rationally designed tyrosine hydroxylase DNA vaccine induces specific antineuroblastoma immunity

Abstract

Therapeutic vaccination against tumor antigens without induction of autoimmunity remains a major challenge in cancer immunotherapy. Here, we show for the first time effective therapeutic vaccination followed by suppression of established spontaneous neuroblastoma metastases using a tyrosine hydroxylase (TH) DNA minigene vaccine. We identified three novel mouse TH (mTH3) derived peptides with high predicted binding affinity to MHC class I antigen H2-K k according to the prediction program SYFPEITHI and computer modeling of epitopes into the MHC class I antigen binding groove. Subsequently, a DNA minigene vaccine was generated based on the expression vector pCMV-F3Ub encoding mutated ubiquitin (Gly 76 to Ala 76 ) and mTH3. Prophylactic and therapeutic efficacies of this vaccine were established following oral delivery with attenuated Salmonella typhimurium SL7207. Only mice immunized with mTH3 were free of spontaneous liver metastases. This effect was clearly dependent on ubiquitin and high affinity of the mTH epitopes to MHC class I antigens. Specifically, we showed a crucial role for minigene expression as a stable ubiquitin-Ala 76 fusion peptide for vaccine efficacy. The immune response following the mTH3 DNA minigene vaccination was mediated by CD8 + T cells as indicated by infiltration of primary tumors and TH-specific cytolytic activity in vitro. Importantly, no cell infiltration was detectable in TH-expressing adrenal medulla, indicating the absence of autoimmunity. In summary, we show effective therapeutic vaccination against neuroblastoma with a novel rationally designed TH minigene vaccine without induction of autoimmunity providing an important baseline for future clinical application of this strategy.

The PTAP Sequence within the p6 Domain of Human Immunodeficiency Virus Type 1 Gag Regulates Its Ubiquitination and MHC Class I Antigen Presentation

“…This has not only been demonstrated for viral and bacterial Ags, but has also been described as a strategy to successfully break tolerance against tumorassociated self-Ags (84,85).…”

Xenogeneic immunization with human tyrosine hydroxylase DNA vaccines suppresses growth of established neuroblastoma

“…Design and Construction of DNA Vaccines Three different DNA vaccines were designed: vaccines A and B based on the mammalian ubiquitin expression plasmid pCMV-F3Ub, kindly provided by Lindsay Whitton and Fernando Rodriguez, The Scripps Research Institute, La Jolla, CA (20,28); and vaccine C based on pBUD-CE4.1 (= vaccine C; Invitrogen). Vaccine A encodes for the cDNA sequence of hTH (pCMV-hTHcDNA).…”

“…In fact, murine TH-derived DNA vaccines were found to induce a CTL-mediated and NB-directed immune response in mice (19,20). However, in contrast to preclinical mouse data, immune responses achieved in humans with syngeneic DNA vaccines are often disappointing, emphasizing the fact that results from animal models cannot be easily transferred to the human system (21).…”

Novel Therapeutic Approaches for Neuroblastoma

“…Another pre-clinical study have demonstrated that tyrosine hydroxylase and MYCN proteins, which are relatively specific for neuroblastoma cells compared to normal cells, include peptides that can be targets for CTL. Vaccination of mice with tyrosine hydroxylase DNA minigenes can induce CTLs, eradicate established primary NXS2 neuroblastoma tumors, and inhibit spontaneous metastases without induction of autoimmunity [84,85].…”