Design of a Chimeric Vaccine Targeting OPA Protein of Neisseria gonorrhoeae – An Immunoinformatics Approach

Abstract

Gonorrhoea is a sexually transmitted disease caused by the pathogen Neisseria gonorrhoeae. The current treatment includes the administration of antibiotics. As the bacterium is resistant to most antibiotics, alternate methods of treatment are the need of the hour. One alternate strategy is to use vaccines. But to date, no vaccines are available to treat Gonorrhoea. In the present study, opacity proteins (Opa) present on the surface of the gonococcus were chosen to design a chimeric vaccine using the Immunoinformatics approach. Initially, ABCpred was used to predict the epitopes specific to B-cells. The epitopes were checked for antigenicity, allergenicity, toxicity, solubility, stability, and presence of transmembrane helices and signal peptides using various online tools. Epitopes DFGGWRIAADYA and RLENTRFKTHEA passed the criteria and were used to construct the vaccine. The epitopes were also checked for affinity to MHC class 1 and 2 alleles. Subunit B of the Cholera toxin was the adjuvant, and the epitopes were linked using GPGPG linkers. The vaccine construct was modeled using the Robetta server, and the model was validated using the Ramachandran plot using the Molprobity server. The physicochemical properties of the constructed chimeric vaccine were analyzed using the Protparam tool. Molecular Dynamic simulations were performed to understand the stability of the vaccine. The DNA sequence of the vaccine constructs for the expression in E.coli K-12 was reverse-translated using the online tool JCAT.