Exploratory algorithm to devise multi-epitope subunit vaccine by investigating Leishmania donovani membrane proteins

Abstract

Visceral leishmaniasis (VL) is a deadly parasitic infection which affects poorest to poor population living in the endemic countries. Increasing resistant to existing drugs, disease burden and a significant number of deaths, necessitates the need for an effective vaccine to prevent the VL infection. This study employed a combinatorial approach to develop a multi-epitope subunit vaccine by exploiting Leishmania donovani membrane proteins. Cytotoxic T- and helper T-lymphocyte binding epitopes along with suitable adjuvant and linkers were joined together in a sequential manner to design the subunit vaccine. The occurrence of B-cell and IFN-γ inducing epitopes approves the ability of subunit vaccine to develop humoral and cell-mediated immune response. Physiochemical parameters of vaccine protein were also assessed followed by homology modeling, model refinement and validation. Moreover, disulfide engineering was performed for the increasing stability of the designed vaccine and molecular dynamics simulation was performed for the comparative stability purposes and to conform the geometric conformations. Further, molecular docking and molecular dynamics simulation study of a mutated and non-mutated subunit vaccine against TLR-4 immune receptor were performed and respective complex stability was determined. In silico cloning ensures the expression of designed vaccine in pET28a(+) expression vector. This study offers a cost-effective and time-saving way to design a novel immunogenic vaccine that could be used to prevent VL infection.

Communicated by Ramaswamy H. Sarma

Keywords:

• visceral leishmaniasis
• subunit vaccine
• disulfide engineering
• in silico cloning

Acknowledgements

NK and VKP are thankful to the Central University of Rajasthan for providing the computational facility. VSA is thankful to Lady Tata Memorial Trust for providing fellowship. MK is thankful to Department of Biotechnology, Department of Science and Technology – PURSE scheme and University Information Centre, Bharathidasan University for providing the high-performance computational facility.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

RKP is thankful to Department of Science and Technology for providing INSPIRE fellowship.