Development a multi-epitope driven subunit vaccine for immune response reinforcement against Serogroup B of Neisseria meningitidis using comprehensive immunoinformatics approaches

Serogroup B of Neisseria meningitidis is the main cause of mortality due to meningococcal meningitis. Despite of many investigations, there is still no effective vaccine to prevent this serious infection. Therefore, this study was conducted to design a multi-epitope based vaccine through immunoinformatics approaches. The T CD4(+) and TCD8(+) cells along with IFN-gamma inducing epitopes were selected from TspA, FHbp, NspA, TbpB, PilQ and NspA antigens form serogroup B of Neisseria meningitidis. Furthermore, to induce strong helper T lymphocytes (HTLs) responses, Pan HLA DR-binding epitope (PADRE) was used. In addition, loop 5 and 7 of the PorB as a TLR2 agonist were added to the vaccine construct. Physico-chemical properties, secondary and tertiary structures of the proposed construct were assessed. Finally, homology modeling, refinement and molecular docking were carried out to evaluated the construct tertiary structure and protein-protein interaction, respectively. By fusing the CTL, HTL and IFN-gamma predicted epitopes along with suitable adjuvant and linkers, a multi-epitope vaccine was constructed with a TAT sequence of HIV at the N-terminal. Immunoinformatics analyses confirmed a soluble and non-allergic protein with a molecular weight of 62.5 kDa and high antigenicity. Furthermore, the stability of the multi-epitope construct was established and showed strong potential to generate humoral and cell-mediated immune responses. In addition, through molecular docking and dynamic simulation, the microscopic interaction between the vaccine construct and TLR-2 were verified. In summary, immunoinformatics analysis demonstrated that the constructed multi-epitope vaccine had a strong potential of T and B-cell stimulation and it could possibly be used for prophylactic or therapeutic aims to protect against serogroup B of N. meningitidis.