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. 2017 Aug 15;7(1):8285.
doi: 10.1038/s41598-017-08842-w.

Exploring Leishmania secretory proteins to design B and T cell multi-epitope subunit vaccine using immunoinformatics approach

Nazia Khatoon  1 , Rajan Kumar Pandey  1 , Vijay Kumar Prajapati  2
Affiliations

Exploring Leishmania secretory proteins to design B and T cell multi-epitope subunit vaccine using immunoinformatics approach

Nazia Khatoon et al. Sci Rep. .

Abstract

Visceral leishmaniasis (VL) is a fatal form of leishmaniasis which affects 70 countries, worldwide. Increasing drug resistance, HIV co-infection, and poor health system require operative vaccination strategy to control the VL transmission dynamics. Therefore, a holistic approach is needed to generate T and B memory cells to mediate long-term immunity against VL infection. Consequently, immunoinformatics approach was applied to design Leishmania secretory protein based multi-epitope subunit vaccine construct consisting of B and T cell epitopes. Further, the physiochemical characterization was performed to check the aliphatic index, theoretical PI, molecular weight, and thermostable nature of vaccine construct. The allergenicity and antigenicity were also predicted to ensure the safety and immunogenic behavior of final vaccine construct. Moreover, homology modeling, followed by molecular docking and molecular dynamics simulation study was also performed to evaluate the binding affinity and stability of receptor (TLR-4) and ligand (vaccine protein) complex. This study warrants the experimental validation to ensure the immunogenicity and safety profile of presented vaccine construct which may be further helpful to control VL infection.

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Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Figure 1
Figure 1
Schematic diagram of final subunit vaccine construct. The multi-epitope vaccine sequence consisting of 528 amino acid residues; out of which, first 130 residues has been represented as adjuvant followed by CTL (131–228 amino acids) and HTL (229–528 amino acids) epitopes. Adjuvant and CTL epitope has been joined by EAAAK linker (Light purple). Whereas, AAY (pink) and GPGPG (cyan) linkers were used to join the CTL and HTL epitopes, respectively. (HPC = Hypothetical protein conserved; SAP = Surface antigen protein; FA-GAP = FA-GAP repeat protein; TRAP = Translocon-associated protein; SL = Secretory lipase).
Figure 2
Figure 2
B-cell epitopes prediction for the final subunit vaccine construct. (A) The discontinuous B- cell epitopes have been represented as red spheres in the final vaccine model (B) linear B- cell epitopes have been shown in magenta color.
Figure 3
Figure 3
Graphical representation of secondary structure obtained for the final subunit vaccine construct showing alpha-helix (35.8%), beta strands (12.9%) and coils (51.3%).
Figure 4
Figure 4
Final subunit vaccine model structure and validation. (A) The figure represents final 3D model of multi-epitope vaccine obtained after homology modeling and refinement. (B) PROSA validation of 3D structure showing Z-score (−1.52) and (C) Ramachandran plot analysis of refined modeled structure showing 92%, 5.9% and 1% residues in favored, allowed and disallowed region respectively.
Figure 5
Figure 5
Binding site prediction by using CASTp server. Total two binding sites has been obtained where Grey, blue and yellow color residues showing the first binding pocket; green, magenta, cyan and red colored amino acid residues representing the second binding site.
Figure 6
Figure 6
Docked complex of TLR-4 (PDB ID: 4G8A) with subunit vaccine construct. (A) Receptor (TLR-4) has been shown in red color whereas cyan color represents the multi-epitope vaccine as a ligand in the docked complex obtained from PatchDock server. (B) Representing disulfide bond engineered in the most flexible region with high B-factor.
Figure 7
Figure 7
Molecular dynamics simulation study of protein-ligand complex representing. (A) Root Mean Square Deviation of the docked complex backbone for the time duration of 10 ns. (B) Root Mean Square Fluctuation representation of the docked complex side chains for same time duration.
Figure 8
Figure 8
In silico restriction cloning of final vaccine construct into pET28a(+) expression vector where purple part representing the vaccine insert and black circle showing the vector.
See this image and copyright information in PMC

References

    1. De Almeida M, Vilhena V, Barral A, Barral-Netto M. Leishmanial infection: analysis of its first steps. A review. Mem. Inst. Oswaldo. Cruz. 2003;98:861–870. doi: 10.1590/S0074-02762003000700001. - DOI - PubMed
    1. Nagill R, Kaur T, Joshi J, Kaur S. Immunogenicity and efficacy of recombinant 78 kDa antigen of Leishmania donovani formulated in various adjuvants against murine visceral leishmaniasis. Asian. Pac. J. Trop. Med. 2015;8:513–519. doi: 10.1016/j.apjtm.2015.06.008. - DOI - PubMed
    1. Perry M, et al. Arsenic, antimony, and Leishmania: has arsenic contamination of drinking water in India led to treatment-resistant kala-azar? Lancet. 2015;385 doi: 10.1016/S0140-6736(15)60395-6. - DOI - PubMed
    1. Kedzierski L, et al. Leishmaniasis: current treatment and prospects for new drugs and vaccines. Curr. Med. Chem. 2009;16:599–614. doi: 10.2174/092986709787458489. - DOI - PubMed
    1. Prajapati VK, et al. In vitro susceptibility of Leishmania donovani to miltefosine in indian visceral leishmaniasis. Am. J. Trop. Med. Hyg. 2013;89:750–754. doi: 10.4269/ajtmh.13-0096. - DOI - PMC - PubMed

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