Toxoplasma gondii Microneme Protein 3 (TgMIC3): Computational  Probing for Improved Vaccine Design

Masoud  Foroutan; Hamidreza  Majidiani; Fatemeh  Ghaffarifar; Elaheh   Karimzadeh-Soureshjani; Amir  Karimipour-Saryazdi; Ali Dalir  Ghaffari; John  Horton

doi:10.18502/ijpa.v21i1.21639

Masoud Foroutan Department of Basic Medical Sciences, Faculty of Medicine, Abadan University of Medical Sciences, Abadan, Iran
Hamidreza Majidiani Healthy Aging Research Centre, Neyshabur University of Medical Sciences, Neyshabur, Iran
Fatemeh Ghaffarifar Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
Elaheh Karimzadeh-Soureshjani Student Research Committee, Abadan University of Medical Sciences, Abadan, Iran
Amir Karimipour-Saryazdi Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
Ali Dalir Ghaffari Department of Parasitology and Mycology, Faculty of Medicine, Shahed University, Tehran, Iran
John Horton Tropical Projects, Hitchin, United Kingdom

DOI: https://doi.org/10.18502/ijpa.v21i1.21639

Keywords: Toxoplasma gondii; Bioinformatics; In silico; Microneme proteins; Vaccine

Abstract

Background: Microneme protein 3 (MIC3) is a key adhesion molecule in Toxoplasma gondii that is expressed during multiple stages of infection. We aimed to computationally characterize the immunological and structural features of the T. gondii MIC3 protein to assess its potential suitability as a vaccine candidate.

Methods: A comprehensive set of bioinformatics tools and web servers was employed to predict the physicochemical properties, allergenicity, antigenicity, solubility, post-translational modification sites, subcellular localization, transmembrane domains, signal peptides, secondary and tertiary structures, potential B- and T-lymphocyte epitopes, and simulated immune responses of the TgMIC3 protein.

Results: A total of 75 post-translational modification sites were predicted in TgMIC3. Furthermore, secondary structure analysis using GOR IV, SOPMA, and NetSurfP-3.0 indicated that random coils and extended strands were the predominant structural elements. In addition, several high-affinity B- and T-cell epitopes were identified across the protein sequence. Subsequent structural validation revealed that 82.91% and 98.60% of residues were located in favored regions in the initial and refined 3D models, respectively. The findings of the allergenicity and antigenicity assessments indicated that the MIC3 antigen seemed to be a non-allergen with an immunogenic nature. Moreover, immune simulation using the C-ImmSim server demonstrated that TgMIC3 could induce robust humoral and cell-mediated immune responses following three simulated antigen administrations.

Conclusion: This study provides foundational computational evidence supporting the potential of TgMIC3 as a vaccine antigen and offers a useful framework for future experimental investigations targeting vaccine development against acute and latent toxoplasmosis.