Multi-epitope vaccine candidates based on mycobacterial membrane protein large (MmpL) proteins against Mycobacterium ulcerans

Open Biol. 2023 Nov;13(11):230330. doi: 10.1098/rsob.230330. Epub 2023 Nov 8.

Abstract

Buruli ulcer (BU) is a neglected tropical disease. It is caused by the bacterium Mycobacterium ulcerans and is characterized by skin lesions. Several studies were performed testing the Bacillus Calmette-Guérin (BCG) vaccine in human and animal models and M. ulcerans-specific vaccines in animal models. However, there are currently no clinically accepted vaccines to prevent M. ulcerans infection. The aim of this study was to identify T-cell and B-cell epitopes from the mycobacterial membrane protein large (MmpL) proteins of M. ulcerans. These epitopes were analysed for properties including antigenicity, immunogenicity, non-allergenicity, non-toxicity, population coverage and the potential to induce cytokines. The final 8 CD8+, 12 CD4+ T-cell and 5 B-cell epitopes were antigenic, non-allergenic and non-toxic. The estimated global population coverage of the CD8+ and CD4+ epitopes was 97.71%. These epitopes were used to construct five multi-epitope vaccine constructs with different adjuvants and linker combinations. The constructs underwent further structural analyses and refinement. The constructs were then docked with Toll-like receptors. Three of the successfully docked complexes were structurally analysed. Two of the docked complexes successfully underwent molecular dynamics simulations (MDS) and post-MDS analysis. The complexes generated were found to be stable. However, experimental validation of the complexes is required.

Keywords: Buruli ulcer; Mycobacterium ulcerans; immunoinformatics; vaccine design.

MeSH terms

  • Animals
  • Buruli Ulcer* / prevention & control
  • Epitopes, B-Lymphocyte / chemistry
  • Epitopes, T-Lymphocyte
  • Humans
  • Membrane Proteins
  • Molecular Docking Simulation
  • Mycobacterium ulcerans* / chemistry
  • Vaccines*

Substances

  • Membrane Proteins
  • Epitopes, B-Lymphocyte
  • Vaccines
  • Epitopes, T-Lymphocyte