Development of Multi-Epitopes Vaccine against Human Papilloma Virus16 Using the L1 and L2 Proteins as Immunogens

Abstract

Background: Human papillomavirus 16 (HPV16) is a small non-enveloped DNA virus is belonging to Papillomaviridae. It usually causes warts and about 60% of cancer diseases. HPV16 genome consists of double-stranded cDNA of six early and two late proteins. This study attempted to design safe and efficient multi epitopes vaccine from structural proteins (L1 and L2) by using various immunoinformatic databases. The results demonstrated that the predicted vaccine comprised of 408aa and validated in terms of antigenicity, allergenicity, toxicity and stability by putting all critical parameters into consideration. The physiochemical properties displayed isoelectric point (pl) of 10.37. The instability index (II) was 33.6 categorizing vaccine as stable. The aliphatic index was 63.24 and the GRAVY was −0.652 demonstrating the hydrophilicity of the vaccine. Vaccine structures were predicted, refined and validated. Stability of the vaccine was assessed through Ramachandan plot and further assessed by ProSA server. Vaccine solubility was higher than the solubility of E. coli proteins indicating that the vaccine was soluble. Disulfide engineering increased the vaccine stability by substituting the unstable residues with cysteine residues. Vaccine-TLR4 receptor docking resulted in attractive binding energy of –1274.1 kcal/mol and –1450.4kcal/mol for chain A and chain B of the receptor respectively. Reverse transcription of the vaccine protein into a DNA sequence was performed and cloned into a pET30a (+) vector to confirm the clonability of the sequence during microbial expression. Taken together, the vaccine potentially induced immune responses and thus was suitable as a vaccine to combat HPV16 disease. Nonetheless, the efficiency of vaccines must be approved by in vitro and in vivo immunological analysis.