Mervenur Güvendi
1 
, Muhammet Karakavuk
2,3,4 , Aysu Değirmenci Döşkaya
3,4,5 , Hüseyin Can
1,3,4 , Mert Döşkaya
3,4,5 , Adnan Yüksel Gürüz
3,4,5 , Cemal Ün
1,3,4* 1 Department of Biology Molecular Biology Section, Faculty of Science, Ege University, İzmir, Türkiye
2 Ödemiş Vocational School, Ege University, İzmir, Türkiye
3 Vaccine Development Application and Research Center, Ege University, İzmir, Türkiye
4 Department of Vaccine Studies, Institute of Health Sciences, Ege University, İzmir, Türkiye
5 Department of Parasitology, Faculty of Medicine, Ege University, İzmir, Türkiye
Abstract
Introduction: Bartonella henselae represents a significant zoonotic threat for humans and has diagnostic challenges. In addition, any commercial vaccine isn’t currently available.
Methods: In this study, bioinformatics and immunoinformatics analyses were used to identify the vaccine and diagnostic epitopes of B. henselae MopA, VceA, and LemA proteins. Initially, the physicochemical properties, secondary structures, and antigenicity of the MopA, VceA, and LemA proteins from B. henselae were evaluated. Then, B and T-cell epitopes were predicted, and further analyzed in terms of antigenicity, allergenicity, solubility, and homology to the human proteome to determine suitable candidates for the final vaccine construct. The normal mode and molecular docking analyses were performed between the final vaccine construct and the TLR2 receptor. Finally, the immune response against the final vaccine construct was predicted.
Results: In silico analyses identified many B and T-cell epitopes with promising immunological and physicochemical properties. Among these, several epitopes showed high antigenicity scores (EINARVNQI, RAANALTVK, SVQIDTRTK and TSGQVISEDVGIKLE). In addition, the newly designed vaccine construct containing epitopes from MopA, Vce, and LemA proteins was found to interact with TLR2 and may stimulate adaptive immune responses.
Conclusion: The present study provides a comprehensive in silico epitope mapping of MopA, VceA, and LemA proteins of B. henselae. The identified epitopes and the vaccine construct can be candidate antigens for the development of serological tests and peptide vaccines. However, experimental studies are needed to validate their diagnostic performance and immunogenic potential.