Production of Norovirus VLPs to size homogeneity

• Production of NoV VLPs from wt VP1 leads to the formation of 2 sizes of particles.
• Culture conditions affect the ratio of larger over smaller VLPs assembled.
• N-terminal truncated VP1 expression leads to the formation of VLPs of homogeneous size (21 nm diameter).
• VLPs formed by truncated VP1 could be considered as vaccine candidates.

Expression of full-length major capsid protein of Noroviruses (NoVs) in sf9 cells using recombinant baculovirus expression system leads to the formation of virus-like particles (VLPs) with two sizes. In our pursuit of VLPs with uniform sizes, we find that N terminal truncated capsid protein formed primary VLPs with an average size of 21 nm. This kind of VLPs showed similar binding patterns to those produced with full-length major capsid protein. HBGA-VLPs binding assay and saliva-VLPs blocking analysis, as well as stability test demonstrate that the smaller 21 nm VLPs might be an excellent candidate for NoVs vaccine.