Journal Article

Identification of human MHC-I HPV18 E6/E7-specific CD8 + T cell epitopes and generation of an HPV18 E6/E7-expressing adenosquamous carcinoma in HLA-A2 transgenic mice

Wu, T.-C., Peng, Shiwen, Ferrall, Louise, Tsai, Ya-Chea, Xing, Deyin, Hung, Chien-Fu

2022

Overview

Background Human Papillomavirus type 18 (HPV18) is a high-risk HPV that is commonly associated with cervical cancer. HPV18 oncogenes E6 and E7 are associated with the malignant transformation of cells, thus the identification of human leukocyte antigen (HLA)-restricted E6/E7 peptide-specific CD8 + T cell epitopes and the creation of a HPV18 E6/E7 expressing cervicovaginal tumor in HLA-A2 transgenic mice will be significant for vaccine development. Methods In the below study, we characterized various human HLA class I-restricted HPV18 E6 and E7-specific CD8 + T cells mediated immune responses in HLA class I transgenic mice using DNA vaccines encoding HPV18E6 and HPV18E7. We then confirmed HLA-restricted E6/E7 specific CD8 + T cell epitopes using splenocytes from vaccinated mice stimulated with HPV18E6/E7 peptides. Furthermore, we used oncogenic DNA plasmids encoding HPV18E7E6(delD70), luciferase, cMyc, and AKT to create a spontaneous cervicovaginal carcinoma model in HLA-A2 transgenic mice. Results Therapeutic HPV18 E7 DNA vaccination did not elicit any significant CD8 + T cell response in HLA-A1, HLA-24, HLA-B7, HLA-B44 transgenic or wild type C57BL/6 mice, but it did generate a strong HLA-A2 and HLA-A11 restricted HPV18E7-specific CD8 + T cell immune response. We found that a single deletion of aspartic acid (D) at location 70 in HPV18E6 DNA abolishes the presentation of HPV18 E6 peptide (aa67-75) by murine MHC class I. We found that the DNA vaccine with this mutant HPV18 E6 generated E6-specific CD8 + T cells in HLA-A2. HLA-A11, HLA-A24 and HLA-b40 transgenic mice. Of note, HLA-A2 restricted, HPV18 E7 peptide (aa7-15)- and HPV18 E6 peptide (aa97-105)-specific epitopes are endogenously processed by HPV18 positive Hela-AAD (HLA-A * 0201/D d ) cells. Finally, we found that injection of DNA plasmids encoding HPV18E7E6(delD70), AKT, cMyc, and SB100 can result in the development of adenosquamous carcinoma in the cervicovaginal tract of HLA-A2 transgenic mice. Conclusions We characterized various human HLA class I-restricted HPV18 E6/E7 peptide specific CD8 + T cell epitopes in human HLA class I transgenic mice. We demonstrated that HPV18 positive Hela cells expressing chimeric HLA-A2 (AAD) do present both HLA-A2-restricted HPV18 E7 (aa7-15)- and HPV18 E6 (aa97-105)-specific CD8 + T cell epitopes. A mutant HPV18E6 that had a single deletion at location 70 obliterates the E6 presentation by murine MHC class I and remains oncogenic. The identification of these human MHC restricted HPV antigen specific epitopes as well as the HPV18E6/E7 expressing adenosquamous cell carcinoma model may have significant future translational potential.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Adenocarcinoma / Adenosquamous / Adenosquamous cell carcinoma / AKT protein / Analysis / Animals / Antigenic determinants / Antigens / Aspartate / Aspartic Acid / Biomedical and Life Sciences / Biomedicine / Cancer / Carcinoma / Carcinoma, Adenosquamous - complications / CD8 antigen / CD8-Positive T-Lymphocytes / Cervical cancer / Cervix / Deletion / Deoxyribonucleic acid / DNA / DNA vaccines / Epitope / Epitopes / Epitopes, T-Lymphocyte - genetics / Female / Genetic aspects / Genetic engineering / Genetic transformation / HeLa Cells / Histocompatibility antigen HLA / Histocompatibility antigens / HLA histocompatibility antigens / HLA-A Antigens / HLA-A1 Antigen / HLA-A11 Antigen / HLA-A2 / HLA-A2 Antigen - genetics / HLA-A24 Antigen / HLA-B40 Antigen / HLA-B44 Antigen / HLA-B7 Antigen / HPV18 / Human papillomavirus / Human papillomavirus 18 / Humans / Immune response / Immune response (cell-mediated) / Immune system / Immunization / Kinases / Leukocytes / Lymphocytes / Lymphocytes T / Major histocompatibility complex / Medical research / Medicine, Experimental / Mice / Mice, Inbred C57BL / Mice, Transgenic / Mouse model / Mutants / Oncogene Proteins, Viral - genetics / Papillomavirus infections / Papillomavirus Infections - complications / Peptides / Plasmids / Proto-Oncogene Proteins c-akt / Rodents / Splenocytes / Squamous cell carcinoma / T cells / T-Lymphocytes, Cytotoxic / Transgenic mice / Tumors / Vaccination / Vaccine development / Vaccines / Vaccines, DNA - genetics