Bioinformatics analysis of HPV-68 E6 and E7 oncoproteins for designing a therapeutic epitope vaccine against HPV infection.

The incidence and mortality of cervical cancer, which mainly results from the infection of human papillomavirus (HPV) is significantly increasing in Xinjiang. According to the previous research, the incidence of HPV-68 in cervical cancer patients in Xinjiang is significantly higher than in other parts of China. HPV E6 and E7 oncoproteins play a crucial role in cervical cancer, and can be used as ideal targets for therapeutic vaccines. Therefore, we analyzed and identified the possible T-cell and B-cell dominant epitopes and various aspects of HPV-68 E6 and E7 oncoproteins, including the physicochemical properties, secondary and tertiary structures using a bioinformatic approach, which provided a basis for designing an effective HPV infection therapeutic vaccine. The results showed that E6 oncoproteins was an unstable and hydrophilic protein, while E7 oncoproteins was unstable and hydrophilic protein. The secondary structure of the E6 oncoproteins consisted of 45.57% alpha helixes, 14.56% extended strands, 4.43% beta turns and 35.44% random coils. The secondary structure of E7 oncoproteins consisted of 35.45% alpha helixes, 17.27% extended strands, 0.91% beta turns and 46.36% random coils. Moreover, our results identified 5 dominant T-cell epitopes and 6 dominant B-cell epitopes in the E6 oncoproteins structure and 5 dominant T-cell epitopes and 3 dominant B-cell epitopes in E7 oncoproteins. In conclusion, this study provides comprehensive biological information about the HPV-68 E6 and E7 oncoproteins, which will lay a theoretical foundation for multi-epitope vaccines against HPV infection.