Establishment of a cell-based 2009 H1N1 influenza neuraminidase inhibitors evaluation system

This study is to establish a cell-based model targeting to neuraminidase (NA) of the 2009 H1N1 influenza A virus.  NA is an influenza virus structural protein with enzymatic activity of the cleavage of HA-sialic acid interaction to release new viral particles from cells.  A model of HIV-1 (pNL4-3.Luc.R⁻E⁻) based pseudovirions packed with HA hemagglutinin, A/VietNam/1203/2004 (H5N1) and NA A/California/04/ 2009 (H1N1) was established to evaluate compounds activities on NA function.  The viral release can be blocked by neuraminidase inhibitors, oseltamivir and oseltamivir carboxylate, with IC₅₀ of (61 ± 31) nmol·L⁻¹ and (5.5 ± 2.9) nmol·L⁻¹ respectively.  A point mutation of H275Y on NA leads oseltamivir-resistance.  This corresponding mutation was introduced into the system which was also confirmed by oseltamivir and oseltamivir carboxylate.