Novel Immunoinformatics Approaches to Design Multi-epitope Subunit Vaccine for Malaria by Investigating Anopheles Salivary Protein

Abstract

Malaria fever has been pervasive for quite a while in tropical developing regions causing high morbidity and mortality. The causal organism is a protozoan parasite of genus Plasmodium which spreads to the human host by the bite of hitherto infected female Anopheles mosquito. In the course of biting, a salivary protein of Anopheles helps in blood feeding behavior and having the ability to elicit the host immune response. This study represents a series of immunoinformatics approaches to design multi-epitope subunit vaccine using Anopheles mosquito salivary proteins. Designed subunit vaccine was evaluated for its immunogenicity, allergenicity and physiochemical parameters. To enhance the stability of vaccine protein, disulfide engineering was performed in a region of high mobility. Codon adaptation and in silico cloning was also performed to ensure the higher expression of designed subunit vaccine in E. coli K12 expression system. Finally, molecular docking and simulation study was performed for the vaccine protein and TLR-4 receptor, to determine the binding free energy and complex stability. Moreover, the designed subunit vaccine was found to induce anti-salivary immunity which may have the ability to prevent the entry of Plasmodium sporozoites into the human host.

Immunoinformatic and dynamic simulation-based designing of a multi-epitope vaccine against emerging pathogen Elizabethkingia anophelis

“…However, one of the biggest drawbacks in the field of therapeutic proteins is the short halflife of peptides 40 . Interestingly, our vaccine protein half-life in mammalian reticulocytes (in vitro) was 30 hours and more than 20 hours and 10 hours in yeast and E. coli cells in vivo, respectively which is satisfactory based on earlier findings 34,35 . Also, the recombinant proteins should be soluble on overexpression for post-production studies 41 .…”

“…On average, 650 hydrogen bonds were present during the simulation, suggesting strong binding of the vaccine-receptor complex. These values indicate strong complex stability based on previous observations 34,35 . Slight fluctuations in amino acid side chains also indicate the uninterrupted interaction between vaccine and receptor.…”

“…An adjuvant is an immunogenic composition that may boost the specific and long-lasting immune response against an antigen by a variety of mechanisms 68 . Toll-like receptor (TLR) agonists are wellknown for recognizing ligands from many Gram-negative bacteria and also to be a part of the peptidebased subunit vaccine 35 . In addition, TLR4 receptor upregulates TSPO/MBR related proteins by overproducing cytokines 69 .…”

“…The crude model of our multiepitope vaccine protein was refined using GalaxyRefine web-server 76 which is based on the CASP10 tested refinement method 77 . GalaxyRefine performs rehashed structure perturbation followed by overall structural relaxation by performing molecular dynamics simulation 35 . Structure validation is an important step in homology modelling which works based on experimentally validated 3D protein structure.…”

Epitope-based vaccine as a universal vaccination strategy against Toxoplasma gondii infection: A mini-review

“…LGPVKLSAEGPT, TAAKTHTVRGFKV, SYFAADRLVP SAG1, GRA2, GRA7 [41] KLFETTDMY, VRQEAIARALARAAA Anopheles mosquito salivary proteins [70] GNIEGQWALKNHSLVSLSEQVLVSCDNIDD CPA (Cysteine peptidase A) [59] YSNIGVCK [71] QTLIAIHTLAIRYAN Paracoccidioides brasiliensis gp43 antigen [72] RPPIFIRRL, sSVRDRLARL EBNA3 [19] Residues 137-160 and 197-211 VP1 gene of foot-and-mouth disease virus [73] (TAKDGMEYYNKMGELYKQ, (RCLLGFKEVGGKCVPASI) Plasmodium knowlesi merozoite surface protein-142 [7] TCPDKKSTA SAG1 (59-67) [9] KSFKDILPK, STFWPCLLR, AVVSLLRLLK, SSAYVFSVK, AMLTAFFLR) SAG1, SAG2, GRA5, SRS52A, GRA6 [17] appropriate adjuvants that can be used along with epitope-based vaccination strategies and establishing optimal immunization protocols along with evaluation criteria.…”