Unveiling Reverse Vaccinology and Immunoinformatics Towards Saint Louis Encephalitis Virus: A Ray of Hope for Vaccine Development

Prasanna Srinivasan Ramalingam¹Mahalakshmi Aranganathan^1,2Md Sadique Hussain³Sujatha Elangovan¹Gayathri Chellasamy⁴Purushothaman Balakrishnan⁵Mekala Janaki Ramaiah⁶Kyusik Yun⁴SIVAKUMAR A^1*

• ¹Protein Engineering Lab, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
• ²School of Natural Sciences and Mathematics, University of Texas at Dallas, Richardson, Texas, United States
• ³Uttaranchal Institute of Pharmaceutical Sciences, Uttaranchal University, Dehradun, Uttarakhand, India
• ⁴Department of Bionanotechnology, Gachon University, Gyeonggi-do, Republic of Korea
• ⁵Department of Biomaterials, Saveetha Dental College and Hospitals, SIMATS, Saveetha University, Chennai, Tamil Nadu, India
• ⁶K L University, Guntur, Andhra Pradesh, India

Infectious diseases continue to challenge human health with high incidence and mortality rates worldwide. Notably, the adaptability of RNA viruses, highlighted by outbreaks of SARS, MERS, & COVID-19, emphasizes the timely need for effective therapeutics. Saint Louis encephalitis virus (SLEV) belonging to the Flaviviridae family is an RNA virus that mostly affects the central nervous system (CNS) of humans. Although supportive care treatments such as Antiemetics and painkillers are being used against SLEV infection, it still lacks potential therapeutics for the effective treatment. Reverse vaccinology and immunoinformatics approaches help in the identification of suitable epitopes to design a vaccine construct that will activate both B and T-cell mediated responses. Previous studies used only the envelope protein E for the vaccine design, but we have used multiple protein targets to enhance the vaccine efficacy. Thus, in the present study, we have designed a multi-epitope subunit vaccine that specifically targets the Membrane Glycoprotein M, Envelope protein E, and Anchored capsid protein anchC of SLEV. Our results indicated that the vaccine construct is structurally stable, antigenic, non-allergic, non-toxic, and soluble. Additionally, the vaccine construct was structurally refined and indicated significant binding affinity towards the Toll-like receptor 4 (TLR-4) supported by molecular docking and molecular dynamics simulations. Furthermore, it also indicated that it has the potential to induce an immune response. In addition, it has been cloned in the pET-28a (+) vector-6xHis-TEV-ORF9c expression vector for further experimental validation. We also recommend to evaluate the designed vaccine's therapeutic efficacy through In vitro and In vivo studies in the near future.