Critical components of a DNA fusion vaccine able to induce protective cytotoxic T cells against a single epitope of a tumor antigen<sup>1</sup>

Authors: Rice, J., Buchan, S. and Stevenson, F.K.

Journal: Journal of Immunology

Volume: 169

Issue: 7

Pages: 3908-3913

ISSN: 0022-1767

DOI: 10.4049/jimmunol.169.7.3908

Abstract:

DNA vaccines can activate immunity against tumor Ags expressed as MHC class I-associated peptides. However, priming of CD8+ CTL against weak tumor Ags may require adjuvant molecules. We have used a pathogen-derived sequence from tetanus toxin (fragment C (FrC)) fused to tumor Ag sequences to promote Ab and CD4+ T cell responses. For induction of CD8+ T cell responses, the FrC sequence has been engineered to remove potentially competitive MHC class I-binding epitopes and to improve presentation of tumor epitopes. The colon carcinoma CT26 expresses an endogenous retroviral gene product, gp70, containing a known H2-Ld-restricted epitope (AH1). A DNA vaccine encoding gp70 alone was a poor inducer of CTL, and performance was not significantly improved by fusion of full-length FrC. However, use of a minimized domain of FrC, with the AH1 sequence fused to the 3′ position, led to rapid induction of high levels of CTL. IFN-γ-producing epitope-specific CTL were detectable ex vivo and these killed CT26 targets in vitro. The single epitope vaccine was more effective than GM-CSF-transfected CT26 tumor cells in inducing an AH1-specific CTL response and equally effective in providing protection against tumor challenge. Levels of AH1-specific CTL in vivo were increased following injection of tumor cells, and CTL expanded in vitro were able to kill CT26 cells in tumor bearers. Pre-existing immunity to tetanus toxoid had no effect on the induction of AH1-specific CTL. These data demonstrate the power of epitope-specific CTL against tumor cells and illustrate a strategy for priming immunity via a dual component DNA vaccine.

Source: Scopus

Critical components of a DNA fusion vaccine able to induce protective cytotoxic T cells against a single epitope of a tumor antigen.

Authors: Rice, J., Buchan, S. and Stevenson, F.K.

Journal: J Immunol

Volume: 169

Issue: 7

Pages: 3908-3913

ISSN: 0022-1767

DOI: 10.4049/jimmunol.169.7.3908

Abstract:

DNA vaccines can activate immunity against tumor Ags expressed as MHC class I-associated peptides. However, priming of CD8(+) CTL against weak tumor Ags may require adjuvant molecules. We have used a pathogen-derived sequence from tetanus toxin (fragment C (FrC)) fused to tumor Ag sequences to promote Ab and CD4(+) T cell responses. For induction of CD8(+) T cell responses, the FrC sequence has been engineered to remove potentially competitive MHC class I-binding epitopes and to improve presentation of tumor epitopes. The colon carcinoma CT26 expresses an endogenous retroviral gene product, gp70, containing a known H2-L(d)-restricted epitope (AH1). A DNA vaccine encoding gp70 alone was a poor inducer of CTL, and performance was not significantly improved by fusion of full-length FrC. However, use of a minimized domain of FrC, with the AH1 sequence fused to the 3' position, led to rapid induction of high levels of CTL. IFN-gamma-producing epitope-specific CTL were detectable ex vivo and these killed CT26 targets in vitro. The single epitope vaccine was more effective than GM-CSF-transfected CT26 tumor cells in inducing an AH1-specific CTL response and equally effective in providing protection against tumor challenge. Levels of AH1-specific CTL in vivo were increased following injection of tumor cells, and CTL expanded in vitro were able to kill CT26 cells in tumor bearers. Pre-existing immunity to tetanus toxoid had no effect on the induction of AH1-specific CTL. These data demonstrate the power of epitope-specific CTL against tumor cells and illustrate a strategy for priming immunity via a dual component DNA vaccine.

Source: PubMed

Critical components of a DNA fusion vaccine able to induce protective cytotoxic T cells against a single epitope of a tumor antigen

Authors: Rice, J., Buchan, S. and Stevenson, F.K.

Journal: JOURNAL OF IMMUNOLOGY

Volume: 169

Issue: 7

Pages: 3908-3913

ISSN: 0022-1767

DOI: 10.4049/jimmunol.169.7.3908

Source: Web of Science (Lite)

Critical components of a DNA fusion vaccine able to induce protective cytotoxic T cells against a single epitope of a tumor antigen.

Authors: Rice, J., Buchan, S. and Stevenson, F.K.

Journal: Journal of immunology (Baltimore, Md. : 1950)

Volume: 169

Issue: 7

Pages: 3908-3913

eISSN: 1550-6606

ISSN: 0022-1767

DOI: 10.4049/jimmunol.169.7.3908

Abstract:

DNA vaccines can activate immunity against tumor Ags expressed as MHC class I-associated peptides. However, priming of CD8(+) CTL against weak tumor Ags may require adjuvant molecules. We have used a pathogen-derived sequence from tetanus toxin (fragment C (FrC)) fused to tumor Ag sequences to promote Ab and CD4(+) T cell responses. For induction of CD8(+) T cell responses, the FrC sequence has been engineered to remove potentially competitive MHC class I-binding epitopes and to improve presentation of tumor epitopes. The colon carcinoma CT26 expresses an endogenous retroviral gene product, gp70, containing a known H2-L(d)-restricted epitope (AH1). A DNA vaccine encoding gp70 alone was a poor inducer of CTL, and performance was not significantly improved by fusion of full-length FrC. However, use of a minimized domain of FrC, with the AH1 sequence fused to the 3' position, led to rapid induction of high levels of CTL. IFN-gamma-producing epitope-specific CTL were detectable ex vivo and these killed CT26 targets in vitro. The single epitope vaccine was more effective than GM-CSF-transfected CT26 tumor cells in inducing an AH1-specific CTL response and equally effective in providing protection against tumor challenge. Levels of AH1-specific CTL in vivo were increased following injection of tumor cells, and CTL expanded in vitro were able to kill CT26 cells in tumor bearers. Pre-existing immunity to tetanus toxoid had no effect on the induction of AH1-specific CTL. These data demonstrate the power of epitope-specific CTL against tumor cells and illustrate a strategy for priming immunity via a dual component DNA vaccine.

Source: Europe PubMed Central