Bioinformatics-based prediction and screening of immunogenic epitopes of Toxoplasma gondii rhoptry proteins 7, 21 and 22 as candidate vaccine target

Fariha Ayub; Haroon Ahmed; Tehreem Sohail; Khuram Shahzad; Figen Celik; Xu Wang; Sami Simsek; Jianping Cao

doi:10.1016/j.heliyon.2023.e18176

Bioinformatics-based prediction and screening of immunogenic epitopes of Toxoplasma gondii rhoptry proteins 7, 21 and 22 as candidate vaccine target

Heliyon. 2023 Jul 11;9(7):e18176. doi: 10.1016/j.heliyon.2023.e18176. eCollection 2023 Jul.

Authors

Fariha Ayub¹, Haroon Ahmed¹, Tehreem Sohail¹, Khuram Shahzad¹, Figen Celik², Xu Wang³, Sami Simsek², Jianping Cao^{3

4}

Affiliations

¹ Department of Biosciences, COMSATS University Islamabad (CUI), Park Road, Chakh Shahzad, Islamabad, Pakistan.
² Department of Parasitology, Faculty of Veterinary Medicine, Firat University, Elazig, Turkey.
³ National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Key Laboratory of Parasite and Vector Biology, National Health Commission of the People's Republic of China, WHO Collaborating Center for Tropical Diseases, Shanghai, China.
⁴ The School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China.

Abstract

Introduction: Toxoplasmosis is a well-known zoonotic disease caused by Toxoplasma gondii. The main causes of the disease range from eating undercooked or contaminated meat and shellfish to cleaning litter trays into which cats that excreted toxoplasma via faeces. This pathogen can live for a very long time, possibly a lifetime, within the bodies of humans and other animals.

Aims and objectives: This study aimed to predict and analyse candidate immunogenic epitopes for vaccine development by evaluating the physio-chemical properties, multiple sequence alignment, secondary and tertiary structures, phosphorylation sites, transmembrane domains, and signal peptides, of T. gondii rhoptry proteins ROP7, ROP21, and ROP22 using bioinformatics tools.

Methods: To find immunogenic epitopes of rhoptry proteins, numerous bioinformatics web servers were used containing multiple sequence alignment, physiochemical properties, antigenicity and allergenicity, post-translational modification sites (PTMs), signal peptides, transmembrane domains, secondary and tertiary structures, and screening of predicted epitopes. We evaluated immunogenic linear B-cell epitopes as candidate proteins for vaccine development.

Results: Nine epitopes were identified for each protein, and analysis of immunogenicity, revealed three candidate epitopes for ROP7, one for ROP21, and four for ROP22. Among all candidate epitopes, ROP22 contained the most immunogenic epitopes with immunogenicity score of 0.50575.

Conclusion: We acquired detailed information on predicted immunogenic epitopes using in-silico methods. The results provide a foundation for further experimental analysis of toxoplasmosis, and potential vaccine development.

Keywords: Bioinformatics; Epitope; ROP21; ROP22; ROP7; Rhoptry proteins; Toxoplasma gondii; Vaccine.