Effects of NS2B-NS3 protease and furin inhibition on West Nile and Dengue virus replication

Jenny Kouretova,M Zouhir Hammamy,Anton Epp,Kornelia Hardes,Stephanie Kallis,Linlin Zhang,Rolf Hilgenfeld,Ralf Bartenschlager,Torsten Steinmetzer

doi:10.1080/14756366.2017.1306521

Abstract

West Nile virus (WNV) and Dengue virus (DENV) replication depends on the viral NS2B-NS3 protease and the host enzyme furin, which emerged as potential drug targets. Modification of our previously described WNV protease inhibitors by basic phenylalanine analogs provided compounds with reduced potency against the WNV and DENV protease. In a second series, their decarboxylated P1-trans-(4-guanidino)cyclohexylamide was replaced by an arginyl-amide moiety. Compound 4-(guanidinomethyl)-phenylacetyl-Lys-Lys-Arg-NH2 inhibits the NS2B-NS3 protease of WNV with an inhibition constant of 0.11 µM. Due to the similarity in substrate specificity, we have also tested the potency of our previously described multibasic furin inhibitors. Their further modification provided chimeric inhibitors with additional potency against the WNV and DENV proteases. A strong inhibition of WNV and DENV replication in cell culture was observed for the specific furin inhibitors, which reduced virus titers up to 10,000-fold. These studies reveal that potent inhibitors of furin can block the replication of DENV and WNV.

Highlights

West Nile virus (WNV) and Dengue virus (DENV) are mosquitotransmitted pathogenic flaviviruses
Only a marginal antiviral effect was found for compounds 47 and 48 at the highest used concentrations, they are still picomolar furin inhibitors with submicromolar efficacy against the flavivirus protease (Table 3). All of these results suggest that the antiviral effect of these compounds against WNV and DENV-2 is only based on furin inhibition
All of the approved orally available inhibitors against thrombin, factor Xa, DPP IV, ACE, enkephalinase, the proteasome, renin and proteases of HIV and HCV belong to the group of active site directed inhibitors addressing relatively well defined binding pockets

Summary

Introduction

West Nile virus (WNV) and Dengue virus (DENV) are mosquitotransmitted pathogenic flaviviruses. A higher rate of severe neurologic diseases occurred during outbreaks in Eastern Europe since the 1990s, and WNV has moved into the focus of the public in 1999, after the virus has spread to New York City, across the USA, and to neighboring countries[2]. In December 2015, a first tetravalent DENV vaccine developed by Sanofi Pasteur (DengvaxiaVR ) was introduced in Mexico, the Philippines, and Brazil, only partial protection with variations between the different serotypes could be achieved[4]. Additional DENV vaccines are presently in development[5,6]. There is no specific antiviral treatment against WNV and DENV infections available[7,8] and the presently most effective protection is to avoid the bites of virus-transmitting mosquitoes

Methods

Results

Conclusion