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Ramos da Silva J, Ramos Moreno AC, Silva Sales N, de Oliveira Silva M, Aps LRMM, Porchia BFMM, Bitencourt Rodrigues K, Cestari Moreno N, Venceslau-Carvalho AA, Menck CFM, de Oliveira Diniz M, de Souza Ferreira LC. A therapeutic DNA vaccine and gemcitabine act synergistically to eradicate HPV-associated tumors in a preclinical model. Oncoimmunology 2021; 10:1949896. [PMID: 34367730 PMCID: PMC8312617 DOI: 10.1080/2162402x.2021.1949896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Although active immunotherapies are effective strategies to induce activation of CD8+ T cells, advanced stage tumors require further improvements for efficient control. Concerning the burden of cancer-related to Human papillomavirus (HPV), particularly the high incidence and mortality of cervical cancer, our group developed an approach based on a DNA vaccine targeting the HPV-16 E7 oncoprotein (pgDE7h). This immunotherapy is capable of inducing an antitumour CD8+ T cell response but show only partial control of tumors in more advanced growth stages. Here, we combined a chemotherapeutic agent (gemcitabine- Gem) with pgDE7h to overcome immunosuppression and improve antitumour responses in a preclinical mouse tumor model. Our results demonstrated that administration of Gem had synergistic antitumor effects when combined with pgDE7h leading to eradication of both early-stages and established tumors. Overall, the antiproliferative effects of Gem observed in vitro and in vivo provided an optimal window for immunotherapy. In addition, the enhanced antitumour responses induced by the combined therapeutic regimen included enhanced frequencies of antigen-presenting cells (APCs), E7-specific IFN-γ-producing CD8+ T cells, and cytotoxic CD8+ T cells and, concomitantly, less pronounced accumulation of immunosuppressive myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs). These findings demonstrated that the combination of Gem and an active immunotherapy strategy show increased effectiveness, leading to a reduced need for multiple drug doses and, therefore, decreased deleterious side effects avoiding resistance and tumor relapses. Altogether, our results provide evidence for a new and feasible chemoimmunotherapeutic strategy that supports future clinical translation.
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Affiliation(s)
- Jamile Ramos da Silva
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
| | - Ana Carolina Ramos Moreno
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
| | - Natiely Silva Sales
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
| | - Mariângela de Oliveira Silva
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
| | - Luana R M M Aps
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
| | - Bruna F M M Porchia
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil.,Laboratory of Tumor Immunology, Department of Immunology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
| | - Karine Bitencourt Rodrigues
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
| | - Natália Cestari Moreno
- DNA Repair Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil.,Mitochondrial Genetics Lab. Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | | | - Carlos Frederico M Menck
- DNA Repair Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
| | - Mariana de Oliveira Diniz
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil.,Division of Infection and Immunity, University College London, 5 University St, Bloomsbury, London, UK
| | - Luís Carlos de Souza Ferreira
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
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Silva MO, Almeida BS, Sales NS, Diniz MO, Aps LRMM, Rodrigues KB, Silva JR, Moreno ACR, Porchia BFMM, Sulczewski FB, Boscardin SB, Ferreira LCS. Antigen Delivery to DEC205 + Dendritic Cells Induces Immunological Memory and Protective Therapeutic Effects against HPV-Associated Tumors at Different Anatomical Sites. Int J Biol Sci 2021; 17:2944-2956. [PMID: 34345218 PMCID: PMC8326119 DOI: 10.7150/ijbs.57038] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 05/02/2021] [Indexed: 12/27/2022] Open
Abstract
The generation of successful anticancer vaccines relies on the ability to induce efficient and long-lasting immune responses to tumor antigens. In this scenario, dendritic cells (DCs) are essential cellular components in the generation of antitumor immune responses. Thus, delivery of tumor antigens to specific DC populations represents a promising approach to enhance the efficiency of antitumor immunotherapies. In the present study, we employed antibody-antigen conjugates targeting a specific DC C-type lectin receptor. For that purpose, we genetically fused the anti-DEC205 monoclonal antibody to the type 16 human papillomavirus (HPV-16) E7 oncoprotein to create a therapeutic vaccine to treat HPV-associated tumors in syngeneic mouse tumor models. The therapeutic efficacy of the αDEC205-E7 mAb was investigated in three distinct anatomical tumor models (subcutaneous, lingual and intravaginal). The immunization regimen comprised two doses of the αDEC205-E7 mAb coadministered with a DC maturation stimulus (Polyinosinic:polycytidylic acid, poly (I:C)) as an adjuvant. The combined immunotherapy produced robust antitumor effects on both the subcutaneous and orthotopic tumor models, stimulating rapid tumor regression and long-term survival. These outcomes were related to the activation of tumor antigen-specific CD8+ T cells in both systemic compartments and lymphoid tissues. The αDEC205-E7 antibody plus poly (I:C) administration induced long-lasting immunity and controlled tumor relapses. Our results highlight that the delivery of HPV tumor antigens to DCs, particularly via the DEC205 surface receptor, is a promising therapeutic approach, providing new opportunities for the development of alternative immunotherapies for patients with HPV-associated tumors at different anatomical sites.
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Affiliation(s)
- Mariângela O Silva
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Bianca S Almeida
- Laboratory of Antigen Targeting to Dendritic Cells, Department of Parasitology, Institute of Biomedical Sciences University of São Paulo, São Paulo, Brazil
| | - Natiely S Sales
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Mariana O Diniz
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Luana R M M Aps
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Karine B Rodrigues
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Jamile R Silva
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Ana C R Moreno
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Bruna F M M Porchia
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Fernando B Sulczewski
- Laboratory of Antigen Targeting to Dendritic Cells, Department of Parasitology, Institute of Biomedical Sciences University of São Paulo, São Paulo, Brazil
| | - Silvia B Boscardin
- Laboratory of Antigen Targeting to Dendritic Cells, Department of Parasitology, Institute of Biomedical Sciences University of São Paulo, São Paulo, Brazil
| | - Luís C S Ferreira
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
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Silva JR, Sales NS, Silva MO, Aps LRMM, Moreno ACR, Rodrigues EG, Ferreira LCS, Diniz MO. Expression of a soluble IL-10 receptor enhances the therapeutic effects of a papillomavirus-associated antitumor vaccine in a murine model. Cancer Immunol Immunother 2019; 68:753-763. [PMID: 30806747 PMCID: PMC11028134 DOI: 10.1007/s00262-018-02297-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 12/28/2018] [Indexed: 12/25/2022]
Abstract
The presence of IL-10, produced either by tumor cells or immunosuppressive cells, is frequently associated with a poor prognosis for cancer progression. It may also negatively impact anticancer treatments, such as immunotherapies, that otherwise would promote the activation of cytotoxic T cells capable of detecting and destroying malignant cells. In the present study, we evaluated a new adjuvant approach for anticancer immunotherapy using a plasmid vector encoding a soluble form of the IL-10 receptor (pIL-10R). pIL-10R was coadministered to mice with a DNA vaccine encoding the type 16 human papillomavirus (HPV-16) E7 oncoprotein genetically fused with glycoprotein D of herpes simplex virus (HSV) (pgDE7h). Immunization regimens based on the coadministration of pIL-10R and pgDE7h enhanced the antitumor immunity elicited in mice injected with TC-1 cells, which express HPV-16 oncoproteins. The administration of the DNA vaccines by in vivo electroporation further enhanced the anticancer effects of the vaccines, leading to the activation of tumor-infiltrating polyfunctional E7-specific cytotoxic CD8+ T cells and control of the expansion of immunosuppressive cells. In addition, the combination of immunotherapy and pIL-10R allowed the control of tumors in more advanced growth stages that otherwise would not be treatable by the pgDE7h vaccine. In conclusion, the proposed treatment involving the expression of IL-10R enhanced the antitumor protective immunity induced by pgDE7h administration and may contribute to the development of more efficient clinical interventions against HPV-induced tumors.
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Affiliation(s)
- Jamile R Silva
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, SP, 05508-000, Brazil
| | - Natiely S Sales
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, SP, 05508-000, Brazil
| | - Mariângela O Silva
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, SP, 05508-000, Brazil
| | - Luana R M M Aps
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, SP, 05508-000, Brazil
| | - Ana C R Moreno
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, SP, 05508-000, Brazil
| | - Elaine G Rodrigues
- Tumor Immunobiology Laboratory, Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina, Federal University of São Paulo, São Paulo, Brazil
| | - Luís C S Ferreira
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, SP, 05508-000, Brazil.
| | - Mariana O Diniz
- Vaccine Development Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, SP, 05508-000, Brazil
- Division of Infection and Immunity, University College London, 5 University St, Bloomsbury, London, WC1E 6JF, UK
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Sales NS, Diniz MDO, Silva JR, Silva MDO, Porchia BFMM, Aps LRMM, Ferreira LCS. Abstract A62: In vivo electroporation improves the immune responses induced by a DNA vaccine and confers complete antitumor protection against HPV-associated tumors. Clin Cancer Res 2018. [DOI: 10.1158/1557-3265.tcm17-a62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Cervical cancer associated with persistent papilloma virus infections (HPV) is a public health problem and represents the third most frequent type of cancer in women. Our group developed a DNA vaccine against HPV-induced tumors based on the expression of the HPV-16 E7 oncoprotein genetically fused to the HSV-1 glycoprotein D (gD) (pgDE7h). This vaccine is capable of promoting antitumoral effects against tumor cells expressing HPV-16 E6 and E7 proteins (TC-1 cells) and induces specific cellular immune responses. In view of the low success rate of DNA vaccines in clinical trials, in vivo electroporation (EP) is a promising strategy for plasmid delivery, leading to increased cellular transfection and enhanced immune responses. In this study, C57BL/6 mice were inoculated with TC-1 cells subcutaneously and immunized 3 days later with pgDE7h intramuscularly, associated or not with EP. Immune responses were analyzed 14 days after vaccination and tumor growth was monitored for 60 days. Similar antitumor effects were obtained with 10-fold less DNA associated with EP when compared to the group that was inoculated only with DNA, reaching around 20% of tumor-free mice. Dose-response curves indicated that maximum protective immunity was achieved with 50 ug of vaccine inoculated with EP, promoting 100% of antitumor protection. This group also had enhanced frequencies of cytotoxic lymphocytes expressing the degranulation marker CD107a and high in vivo cytotoxic activities. Besides that, a delayed vaccination performed 10 days after the TC-1 injection led to 70% of tumor-free mice until the end of the observed period. Collectively, these data confirmed that EP can be used as an efficient method of DNA vaccine delivery and should be further studied to improve the chances of cancer vaccine success in clinical trials.
Citation Format: Natiely Silva Sales, Mariana de Oliveira Diniz, Jamile Ramos Silva, Mariângela de Oliveira Silva, Bruna F. M. M. Porchia, Luana R. M. M. Aps, Luis Carlos Souza Ferreira. In vivo electroporation improves the immune responses induced by a DNA vaccine and confers complete antitumor protection against HPV-associated tumors [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr A62.
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Aps LRMM, Tavares MB, Rozenfeld JHK, Lamy MT, Ferreira LCS, Diniz MO. Bacterial spores as particulate carriers for gene gun delivery of plasmid DNA. J Biotechnol 2016; 228:58-66. [PMID: 27130499 DOI: 10.1016/j.jbiotec.2016.04.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 04/11/2016] [Accepted: 04/12/2016] [Indexed: 12/11/2022]
Abstract
Bacillus subtilis spores represent a suitable platform for the adsorption of proteins, enzymes and viral particles at physiological conditions. In the present work, we demonstrate that purified spores can also adsorb DNA on their surface after treatment with cationic molecules. In addition, we demonstrate that DNA-coated B. subtilis spores can be used as particulate carriers and act as an alternative to gold microparticles for the biolistic (gene gun) administration of plasmid DNA in mice. Gene gun delivery of spores pre-treated with DODAB (dioctadecyldimethylammonium bromide) allowed efficient plasmid DNA absorption and induced protein expression levels similar to those obtained with gold microparticles. More importantly, we demonstrated that a DNA vaccine adsorbed on spores can be loaded into biolistic cartridges and efficiently delivered into mice, which induced specific cellular and antibody responses. Altogether, these data indicate that B. subtilis spores represent a simple and low cost alternative for the in vivo delivery of DNA vaccines by the gene gun technology.
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Affiliation(s)
- Luana R M M Aps
- Vaccine Development Laboratory, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Milene B Tavares
- Vaccine Development Laboratory, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | | | - M Teresa Lamy
- Institute of Physics, University of São Paulo, Brazil
| | - Luís C S Ferreira
- Vaccine Development Laboratory, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Mariana O Diniz
- Vaccine Development Laboratory, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
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Aps LRMM, Diniz MO, Porchia BFMM, Sales NS, Moreno ACR, Ferreira LCS. Bacillus subtilis spores as adjuvants for DNA vaccines. Vaccine 2015; 33:2328-34. [PMID: 25819710 DOI: 10.1016/j.vaccine.2015.03.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Revised: 03/05/2015] [Accepted: 03/16/2015] [Indexed: 12/14/2022]
Abstract
Recently, Bacillus subtilis spores were shown to be endowed with strong adjuvant capacity when co-administered with purified antigenic proteins. In the present study we assessed whether spores possess adjuvant properties when combined with DNA vaccines. We showed that B. subtilis spores promoted the activation of dendritic cells in vitro and induced migration of pro-inflammatory cells after parenteral administration to mice. Likewise, co-administration of spores with a DNA vaccine encoding the human papillomavirus type 16 (HPV-16) E7 protein enhanced the activation of antigen-specific CD8(+) T cell responses in vivo. Mice immunized with the DNA vaccine admixed with spores presented a protective immunity increase to previously implanted tumor cells, capable of expressing HPV-16 oncoproteins. Finally, we observed that the adjuvant effect can vary accordingly to the number of co-administered spores which may be ascribed with the ability to induce. Collectively, the present results demonstrate for the first time that B. subtilis spores can also confer adjuvant effects to DNA vaccines.
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Affiliation(s)
- Luana R M M Aps
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Mariana O Diniz
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Bruna F M M Porchia
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Natiely S Sales
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Ana Carolina R Moreno
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Luís C S Ferreira
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
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Avila LA, Aps LRMM, Sukthankar P, Ploscariu N, Gudlur S, Šimo L, Szoszkiewicz R, Park Y, Lee SY, Iwamoto T, Ferreira LCS, Tomich JM. Branched Amphiphilic Cationic Oligopeptides Form Peptiplexes with DNA: A Study of Their Biophysical Properties and Transfection Efficiency. Mol Pharm 2015; 12:706-15. [DOI: 10.1021/mp500524s] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- L. Adriana Avila
- Department of Biochemistry & Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506-3902, United States
| | - Luana R. M. M. Aps
- Institute
of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo 05508-900, Brazil
| | - Pinakin Sukthankar
- Department of Biochemistry & Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506-3902, United States
| | - Nicoleta Ploscariu
- Department
of Physics, Kansas State University, Manhattan, Kansas 66506-2601, United States
| | - Sushanth Gudlur
- Department of Biochemistry & Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506-3902, United States
| | - Ladislav Šimo
- Department
of Entomology, Kansas State University, Manhattan, Kansas 66506-4004, United States
| | - Robert Szoszkiewicz
- Department
of Physics, Kansas State University, Manhattan, Kansas 66506-2601, United States
| | - Yoonseong Park
- Department
of Entomology, Kansas State University, Manhattan, Kansas 66506-4004, United States
| | - Stella Y. Lee
- Division
of Biology, Kansas State University, Manhattan, Kansas 66506-3902, United States
| | - Takeo Iwamoto
- Division
of Biochemistry, Core Research Facilities, Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Luis C. S. Ferreira
- Institute
of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo 05508-900, Brazil
| | - John M. Tomich
- Department of Biochemistry & Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506-3902, United States
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Diniz MO, Cariri FAMO, Aps LRMM, Ferreira LCS. Enhanced therapeutic effects conferred by an experimental DNA vaccine targeting human papillomavirus-induced tumors. Hum Gene Ther 2014; 24:861-70. [PMID: 24007495 DOI: 10.1089/hum.2013.102] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Human papillomavirus (HPV) infection is responsible for all cervical cancer cases, other anogenital cancers, and head and neck tumors. The epidemiological relevance of HPV-induced tumors reinforces the need for the development of therapeutic antitumor vaccines. Clinical trials with different vaccine formulations, particularly DNA vaccines, have provided promising results but have still been unable to achieve the immunogenicity required for use in infected patients. In experimental conditions, anticancer HPV-specific vaccines induced E7-specific CD8(+) T-cell responses but did not confer full therapeutic antitumor protection in mice with transplanted HPV-expressing TC-1 cells, which are the most frequently used nonclinical protection correlate for antitumor effects. Our group has developed a DNA vaccine strategy based on the fusion of HPV oncoproteins to the herpes virus gD protein. This vaccine promoted the induction of antigen-specific cytotoxic CD8(+) T-cell responses and partial antitumor therapeutic effects based on the blockade of coinhibitory signals and the enhancement of coactivation mechanisms. In the present study, we report conditions leading to full therapeutic antitumor effects using the TC-1 cell murine model after a single vaccine dose. The combination of a coadministered plasmid encoding IL-2, optimization of the coding sequence for mammalian cells, and the use of different delivery routes resulted in enhancements of the E7-specific cytotoxic CD8(+) T-cell responses and full therapeutic protection under experimental conditions. The combination of these strategies augmented the potency of the DNA vaccine formulation to levels not previously achieved by other therapeutic antitumor vaccines under similar experimental conditions, including some that have been taken to clinical trials.
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Affiliation(s)
- Mariana O Diniz
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo , São Paulo, SP, 05508-900 Brazil
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