Identification of immunotherapeutic epitope of E5 protein of human papillomavirus-16: An in silico approach.

Cervical cancer is one of the most common gynaecological cancer in India and contributes 1/3rd of global burden. High risk-human papillomavirus (HR-HPV) is the major etiological factor for development of cervical cancer. Two available HPV vaccines provide protection against HPV induced cervical malignancy. However, vaccines having therapeutic values are of utmost priority. Till date, most of HPV therapeutic vaccines are focused on two major HPV oncoproteins (E6/E7). HPV-E5 which acts by altering the activity of cellular proteins, mainly growth factor pathways emerges as a new therapeutic target. In present study, we predicted the candidate B-cell and T-cell epitopes of HPV16-E5, which can be used for HPV immunotherapy. We identified that epitope SAFRCFIVYIIFVY as most potent peptide for HLA-A*11:01 having percentile value of 0.5 and immunogenicity score of 0.69558. For MHC-II, epitopes IPLFLIHTHARFLIT for HLA-DRB1*14:01 alleles have the lowest IC50 value (18.13 nM). The identification of structural feature and immunogenic epitopes provides the best information for development of drugs or vaccine. In conclusion, the expression of E5 protein was detected in the early phase of the HPV infection, which gives an opportunity to target HPV-E5 that would help in the prevention and progression of the precancerous lesion to invasive carcinomas.