Development of peptides targeting receptor binding site of the envelope glycoprotein to contain the West Nile virus infection

Mangesh Bhide,Zuzana Tkáčová,Amod Kulkarni,Jana Hruškovicová,Katarína Bhide,Patrícia Mertinková,Evelína Mochnáčová

doi:10.1038/s41598-021-99696-w

Abstract

West Nile virus (WNV), re-emerging neurotropic flavivirus, can cross the blood–brain barrier (BBB) and cause fatal encephalitis and meningitis. Infection of the human brain microvascular endothelial cells (hBMECs), building blocks of the BBB, represents the pivotal step in neuroinvasion. Domain III (DIII) of the envelope (E) glycoprotein is a key receptor-binding domain, thus, it is an attractive target for anti-flavivirus strategies. Here, two combinatorial phage display peptide libraries, Ph.D.-C7C and Ph.D.-12, were panned against receptor-binding site (RBS) on DIII to isolate peptides that could block DIII. From series of pannings, nine peptides (seven 7-mer cyclic and two 12-mer linear) were selected and overexpressed in E. coli SHuffle T5. Presence of disulfide bond in 7-mer peptides was confirmed with thiol-reactive maleimide labeling. Except for linear peptide 19 (HYSWSWIAYSPG), all peptides proved to be DIII binders. Among all peptides, 4 cyclic peptides (CTKTDVHFC, CIHSSTRAC, CTYENHRTC, and CLAQSHPLC) showed significant blocking of the interaction between DIII and hBMECs, and ability to neutralize infection in cultured cells. None of these peptides showed toxic or hemolytic activity. Peptides identified in this study may serve as potential candidates for the development of novel antiviral therapeutics against WNV.

Highlights

West Nile virus (WNV), re-emerging neurotropic flavivirus, can cross the blood–brain barrier (BBB) and cause fatal encephalitis and meningitis
Once infected with WNV, brain microvascular endothelial cells (BMECs) induces the expression of adhesion molecules, which promotes the transendothelial migration of leukocytes, modulates BBB p ermeability[16,17] and assists in the trafficking of WNV-infected immune c ells[12]
Negative controls in ELISA did not show absorbance more than 0.37, which indicates the specific binding of the amplified phages to the recombinant DIII (rDIII) (Fig. 1A)

Summary

Introduction

West Nile virus (WNV), re-emerging neurotropic flavivirus, can cross the blood–brain barrier (BBB) and cause fatal encephalitis and meningitis. A phage display was employed using two combinatorial Ph.D. libraries (New England Biolabs, USA) to isolate 7-mer cyclic or 12-mer linear peptides, which bind to the DIII of the E protein.

Results

Conclusion