Heterologous Expression of Human Norovirus GII.4 VP1 Leads to Assembly of T=4 Virus-Like Particles

Abstract

18 19 Human noroviruses are a leading cause of acute gastroenteritis, yet there are still no 20 vaccines or antivirals available. Expression of the norovirus capsid protein (VP1) in 21 insect cells typically results in the formation of virus-like particles (VLPs) that are 22 IMPORTANCE 39 40The discovery that the GII.4 VLPs have a T=4 symmetry is of significance, since this 41 represents the first known T=4 calicivirus structure. Interestingly, the GII.4 2012 42 variant shares 96% amino acid identity with a current GII.4 VLP vaccine candidate 43 sequence, which suggests that this vaccine might also have a T=4 symmetry. Our 44 previous results with these GII.4 VLPs showed functional binding properties to 45 antibodies and Nanobodies that were raised against T=3 (GII.10) VLPs. This suggests 46 that the T=4 VLPs were antigenically comparable to T=3 particles, despite the 47 (EM). The VLPs were diluted 1:30 in distilled water and applied to EM grids. The 130 grids were washed with distilled water, stained with 0.75% uranyl acetate, and the 131 excess uranyl acetate was removed with filter paper. Virion samples were applied to 132 EM grids, washed with water, fixed with 4% glutaraldehyde, and then stained as 133 above. EM images were acquired on a Zeiss 910 electron microscope at 50,000× 134 magnification. 135

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“…In this study, a baculovirus expression system was used to successfully obtain GII.P16-GII.2 recombinant norovirus VLPs similar in shape and in size to the natural norovirus. Moreover, particle size analysis the VLP was 39.59nm, similar to the size previously reported for norovirus (28).…”

DataSheet_1.docx

“…In this study, a baculovirus expression system was used to successfully obtain GII.P16-GII.2 recombinant norovirus VLPs similar in shape and in size to the natural norovirus. Moreover, particle size analysis indicated the average VLP size was 39.59nm, similar to the size previously reported for norovirus (28). CD8+ T cells provide host defense and protective immunity by directly binding and eliminating foreign pathogens.…”

Image_1.tif

“…In this study, a baculovirus expression system was used to successfully obtain GII.P16-GII.2 recombinant norovirus VLPs similar in shape and in size to the natural norovirus. Moreover, particle size analysis indicated the average VLP size was 39.59nm, similar to the size previously reported for norovirus (28). CD8+ T cells provide host defense and protective immunity by directly binding and eliminating foreign pathogens.…”