Development of a Surrogate Neutralization Assay for Norovirus Vaccine Evaluation at the Cellular Level.

Xiaoli Wang,Chao Zhang,Pei Xiong,Qingwei Liu,Shuxia Wang,Yu Zhou,Zhong Huang

doi:10.3390/v10010027

Abstract

Noroviruses (NoVs) are the main pathogens responsible for sporadic and epidemic nonbacterial gastroenteritis, causing an estimated 219,000 deaths annually worldwide. There is no commercially available vaccine for NoVs, due partly to the difficulty in establishing NoV cell culture models. The histo-blood group antigen (HBGA) blocking assay is used extensively to assess the protective potential of candidate vaccine-elicited antibodies, but there is still no widely used cellular evaluation model. In this study, we have established a cell line-based NoV vaccine evaluation model through the construction of human α1,2-fucosyltransferase 2-overexpressing 293T (293T-FUT2) cell lines. The 293T-FUT2 cells stably expressed H type 2 and Lewis y antigens. Virus-like particles (VLPs) of the NoV prototype strain genogroup I.1 (GI.1) and the predominant strains GII.4 and GII.17 could attach to the cell line efficiently in a dose-dependent manner. Importantly, antisera against these NoV VLPs could inhibit the attachment of the VLPs, where the inhibitory effects measured by the attachment inhibition assay correlated significantly with the antibody levels determined by the HBGA blocking assay. Collectively, our attachment inhibition assay could serve as a surrogate neutralization assay for the evaluation of NoV vaccines at the cellular level.

Highlights

Noroviruses (NoVs), belonging to the Caliciviridae family, are the main causes of sporadic and epidemic nonbacterial gastroenteritis [1]
When compared with the FUT2 RNA level in wild-type 293T cells, the level was significantly increased by 100–900 folds in the #1–8 cell lines and mixed-cell population of 293T-FUT2 (Figure 1)
Suggested that the inhibitory effect conferred by virus-like particles (VLPs)-specific antisera was specific and the cellular. These results suggested that the inhibitory effect conferred by NoV VLP-specific antisera was specific inhibition assay may be usedassay for the evaluation and the cellular inhibition may be used of forNoV

Summary

Introduction

Noroviruses (NoVs), belonging to the Caliciviridae family, are the main causes of sporadic and epidemic nonbacterial gastroenteritis [1]. Vaccines should be an effective means for preventing NoV infection, the exploration of this option, including vaccine development and evaluation, has been hindered, owing to the difficulty in establishing an applicable NoV cell culture model [5,6]. Several evaluation models, including the histo-blood group antigen (HBGA) blocking assay [7,8], hemagglutination inhibition (HAI) assay [9], and stem cell-derived human intestinal enteroid (HIE)-based neutralization assay [6], are currently used to assess NoV vaccines in vitro. The HIE-based neutralization assay is the only cellular model used in NoV vaccine assessment [6], but this model has not been widely used owing to the difficulty in obtaining stem cells from human intestinal tissues

Methods

Results

Conclusion