A novel recombinant protein vaccine containing the different E7 proteins of the HPV16, 18, 6, 11 E7 linked to the HIV-1 Tat (47-57) improve cytotoxic immune responses.

Tahoora Mousavi,Mohammad Reza Haghshenas,Reza Valadan,Alireza Rafiei,Ali Abbasi

doi:10.1007/s10529-021-03166-2

Abstract

Human papillomavirus infection (HPV) is the most common viral infection which is causes of cervical, penal, vulvar, anal and, oropharyngeal cancer. E7 protein of HPV is a suitable target for induction of T cell responses and controlling HPV-related cancer. The aim of the current study was to designed and evaluated a novel fusion protein containing the different E7 proteins of the HPV 16, 18, 6 and 11, linked to the cell-penetrating peptide HIV-1 Tat 49-57, in order to improve cytotoxic immune responses in in-vitro and in-vivo. In this study whole sequence of HPV16,18,6,11 E7-Tat (47-57) and HPV16,18,6,11 E7 cloned into the vector and expressed in E. coli (BL21). The purified protein was confirmed by SDS page and western blotting and then injected into the C57BL/6 mice. The efficiency of the fusion protein vaccine was assessed by antibody response assay, cytokine assay (IL-4 and IFN-γ), CD + 8 cytotoxicity assay and tumor challenge experiment. Result showed that fusion proteins containing Adjuvant (IFA,CFA) could express higher titer of antibody. Also, we showed that vaccination with E7-Tat and, E7-Tat-ADJ induced high frequencies of E7-specific CD8 + T cells and CD107a expression as well as IFN-γ level and enhanced long-term survival in the therapeutic animal models. Our finding suggested that this novel fusion protein vaccine was able to induce therapeutic efficacy and immunogenicity by improving CD8 + T cell in TC-1 tumor bearing mice; so this vaccine may be appreciated for research against HPV and tumor immunotherapies.

Highlights

Human papillomavirus infection (HPV) is the most common viral infection which is causes cancer or genital warts (Haghshenas, Mousavi et al 2016)
In this study whole sequence of HPV16,18,6,11 E7-Tat (47-57) and HPV16,18,6,11 E7 cloned into the vector and expressed in E.coli (BL21)
We showed that vaccination with E7-Tat and, E7-Tat-ADJ induced high frequencies of E7-specific CD8+ T cells and CD107a expression as well as IFN-γ level and enhanced long-term survival in the therapeutic animal models

Summary

Introduction

Human papillomavirus infection (HPV) is the most common viral infection which is causes cancer or genital warts (Haghshenas, Mousavi et al 2016). Low-risk types such as 6 and 11 lead to 99% of genital warts and laryngeal papillomatosis; while 70% of cancers are related to high-risk types, such as 16, 18 (Akhondnezhad, Haghshenas et al 2018). E6 oncoprotein, is a key factor in tumor progression, act as P53 suppressor through binding to its C-terminal region. This protein is a transcription factor that controls cell proliferation by preventing the G1 to S phase (Gulati, Huang et al 2018). E7 oncoprotein is a small nuclear protein with no enzymatic activity This protein is bound to the hypophosphorylated retinoblastoma protein (PRb); in this situation, the cell cycle moves to the S phase. Regarding the importance of E6 and E7 in induction and maintenance of cellular transformation, these early genes have been reported as suitable targets for designing anti-tumor vaccines and controlling HPV infection (Li, Chen et al 2017) (Tang, Yin et al 2012)

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