Generation of recombinant norovirus-like particles (VLP) in the human endothelial kidney cell line 293T

Noroviruses (NVs) are the major cause of non-bacterial outbreaks of gastroenteritis. Here we report a new alternative system to generate recombinant NV virus-like particles (rNV-VLP) in a human endothelial kidney cell line (HEK). Transfecting HEK-293T cells with an expression vector coding for the ORF-2 gene lead to the expression of the viral structural protein VP1 which spontaneously assembled into virus-like particles (VLP), as shown by electron microscopy. The transfected cells did not show a cytopathic effect and released rNV-VLP into the culture medium. The HEK-293T cell derived particles were morphologically indistinguishable to the rNV-VLP produced from baculovirus and the Venezuelan equine encephalitis virus (VEE)-replicon. The produced particles were stable for at least 2.5 months at 4 degrees C.