Design of a novel multi-epitope vaccine candidate against Chlamydia trachomatis using structural and nonstructural proteins: an immunoinformatics study

Abstract

Chlamydia trachomatis (C. trachomatis) is an obligate intracellular bacterium which causes eye and sexually transmitted infections. During pregnancy, the bacterium is associated with preterm complications, low weight of neonates, fetal demise and endometritis leading to infertility. The aim of our study was design of a multi-epitope vaccine (MEV) candidate against C. trachomatis. After protein sequence adoption from the NCBI, potential epitopes toxicity, antigenicity, allergenicity, MHC-I and MHC-II binding, cytotoxic T lymphocytes (CTLs), Helper T lymphocytes (HTLs) and interferon-γ (IFN-γ)- induction were predicted. The adopted epitopes were fused together using appropriate linkers. In the next step, the MEV structural mapping and characterization, three-dimensional (3D) structure homology modeling and refinement were also performed. The MEV candidate interaction with the toll-like receptor 4 (TLR4) was also docked. The immune responses simulation was assessed using the C-IMMSIM server. Molecular dynamic (MD) simulation verified the structural stability of the TLR4-MEV complex. The Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) approach demonstrated the MEV high affinity of binding to the TLR4, MHC-I and MHC-II. The MEV construct was also stable and water soluble and had enough antigenicity and lacked allergenicity with stimulation of T cells and B cells and INF-γ release. The immune simulation confirmed acceptable responses of both the humoral and cellular arms. It is proposed that in vitro and in vivo studies are needed to evaluate the findings of this study.

Communicated by Ramaswamy H. Sarma

Keywords:

• Chlamydia trachomatis
• multi-epitope vaccine
• surface proteins
• sexually transmitted diseases
• molecular dynamic simulation

Disclosure statement

The authors have declared that no competing interests exist.

Data availability statement

All the data of the manuscript has been included in the manuscript and related Supplementary Information file.

Authors’ contribution

AF, AGh and EB designed the study and performed the procedure, GhRLAl-A and FAM supported the work and edited the manuscript. SH and AK contributed in data and results of immune simulation analyses and manuscript text revision. MA provided facilities for computational study.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.