Development of DNA Vaccine Targeting E6 and E7 Proteins of Human Papillomavirus 16 (HPV16) and HPV18 for Immunotherapy in Combination with Recombinant Vaccinia Boost and PD-1 Antibody

• Published in: mBio Vol. 12; no. 1
• Main Authors: Peng, Shiwen, Ferrall, Louise, Gaillard, Stephanie, Wang, Chenguang, Chi, Wei-Yu, Huang, Chuan-Hsiang, Roden, Richard B. S., Wu, T.-C., Chang, Yung-Nien, Hung, Chien-Fu
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 19.01.2021
• Subjects: Animals; Antibodies, Monoclonal - administration & dosage; Bacterial Proteins - genetics; Bacterial Proteins - immunology; DNA-Binding Proteins - genetics; DNA-Binding Proteins - immunology; Female; HSP70 Heat-Shock Proteins - genetics; HSP70 Heat-Shock Proteins - immunology; Human papillomavirus 16 - drug effects; Human papillomavirus 16 - genetics; Human papillomavirus 16 - immunology; Human papillomavirus 18 - drug effects; Human papillomavirus 18 - genetics; Human papillomavirus 18 - immunology; Humans; Immunization, Secondary - methods; Mice; Mice, Inbred C57BL; Oncogene Proteins, Viral - genetics; Oncogene Proteins, Viral - immunology; Papillomavirus E7 Proteins - genetics; Papillomavirus E7 Proteins - immunology; Papillomavirus Infections - genetics; Papillomavirus Infections - immunology; Papillomavirus Infections - mortality; Papillomavirus Infections - prevention & control; Papillomavirus Vaccines - administration & dosage; Papillomavirus Vaccines - genetics; Papillomavirus Vaccines - immunology; Programmed Cell Death 1 Receptor - antagonists & inhibitors; Programmed Cell Death 1 Receptor - genetics; Programmed Cell Death 1 Receptor - immunology; Protein Engineering - methods; Recombinant Fusion Proteins - administration & dosage; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - immunology; Repressor Proteins - genetics; Repressor Proteins - immunology; Research Article; Survival Analysis; Therapeutics and Prevention; Uterine Cervical Neoplasms - genetics; Uterine Cervical Neoplasms - immunology; Uterine Cervical Neoplasms - mortality; Uterine Cervical Neoplasms - prevention & control; Vaccination - methods; Vaccines, DNA - administration & dosage; Vaccines, DNA - genetics; Vaccines, DNA - immunology; Vaccinia virus - chemistry; Vaccinia virus - immunology; DNA vaccine; E6; E7; human papillomavirus; HPV18; HPV-associated cancer; PD-1; TA-HPV; HPV16
• ISSN: 2161-2129; 2150-7511; 2150-7511
• DOI: 10.1128/mBio.03224-20

Persistent expression of high-risk human papillomavirus (HPV) E6 and E7 is an obligate driver for several human malignancies, including cervical cancer, wherein HPV16 and HPV18 are the most common types. PD-1 antibody immunotherapy helps a subset of cervical cancer patients, and its efficacy might be improved by combination with active vaccination against E6 and/or E7. Immunotherapy for cervical cancer should target high-risk human papillomavirus types 16 and 18, which cause 50% and 20% of cervical cancers, respectively. Here, we describe the construction and characterization of the pBI-11 DNA vaccine via the addition of codon-optimized human papillomavirus 18 (HPV18) E7 and HPV16 and 18 E6 genes to the HPV16 E7-targeted DNA vaccine pNGVL4a-SigE7(detox)HSP70 (DNA vaccine pBI-1). Codon optimization of the HPV16/18 E6/E7 genes in pBI-11 improved fusion protein expression compared to that in DNA vaccine pBI-10.1 that utilized the native viral sequences fused 3′ to a signal sequence and 5′ to the HSP70 gene of Mycobacterium tuberculosis . Intramuscular vaccination of mice with pBI-11 DNA better induced HPV antigen-specific CD8 + T cell immune responses than pBI-10.1 DNA. Furthermore, intramuscular vaccination with pBI-11 DNA generated stronger therapeutic responses for C57BL/6 mice bearing HPV16 E6/E7-expressing TC-1 tumors. The HPV16/18 antigen-specific T cell-mediated immune responses generated by pBI-11 DNA vaccination were further enhanced by boosting with tissue-antigen HPV vaccine (TA-HPV). Combination of the pBI-11 DNA and TA-HPV boost vaccination with PD-1 antibody blockade significantly improved the control of TC-1 tumors and extended the survival of the mice. Finally, repeat vaccination with clinical-grade pBI-11 with or without clinical-grade TA-HPV was well tolerated in vaccinated mice. These preclinical studies suggest that the pBI-11 DNA vaccine may be used with TA-HPV in a heterologous prime-boost strategy to enhance HPV 16/18 E6/E7-specific CD8 + T cell responses, either alone or in combination with immune checkpoint blockade, to control HPV16/18-associated tumors. Our data serve as an important foundation for future clinical translation. IMPORTANCE Persistent expression of high-risk human papillomavirus (HPV) E6 and E7 is an obligate driver for several human malignancies, including cervical cancer, wherein HPV16 and HPV18 are the most common types. PD-1 antibody immunotherapy helps a subset of cervical cancer patients, and its efficacy might be improved by combination with active vaccination against E6 and/or E7. For patients with HPV16 + cervical intraepithelial neoplasia grade 2/3 (CIN2/3), the precursor of cervical cancer, intramuscular vaccination with a DNA vaccine targeting HPV16 E7 and then a recombinant vaccinia virus expressing HPV16/18 E6-E7 fusion proteins (TA-HPV) was safe, and half of the patients cleared their lesions in a small study (NCT00788164). Here, we sought to improve upon this therapeutic approach by developing a new DNA vaccine that targets E6 and E7 of HPV16 and HPV18 for administration prior to a TA-HPV booster vaccination and for application against cervical cancer in combination with a PD-1-blocking antibody.