Genome-wide CRISPR Screen for Host Factors Associated With Norovirus Infections in Stem Cell-derived Human Intestinal Enteroid Model

The primary objective in this study is to establish a list of host cellular proteins that mediate norovirus infection.

Norovirus is one of the most common pathogens attributed to diarrheal diseases from unsafe food. It is also the primary cause of mortality among young children and adults in foodborne infections. Norovirus is not just a foodborne burden. In a recent meta-analysis, norovirus accounts for nearly one-fifth of all causes of (including person-to-person transmission) acute gastroenteritis in both sporadic and outbreak settings and affects all age groups. Undoubtedly, norovirus is of paramount public health concern in both developed and developing countries. Research efforts to better understand norovirus pathobiology will be necessary for targeted intervention.

From Middle East respiratory syndrome coronavirus to Zika virus, efforts to identify host factors important for mediating virus infection has always been a research priority. Such information will shed light on potential therapeutic targets in antiviral intervention. Norovirus virus-host interaction studies have been hampered by the lack of a robust cell culture model in the past 20 years. In 2016, norovirus has finally been successfully cultivated in a stem cell-derived three-dimensional human gut-like structure called enteroid or mini-gut.

In this study, intestinal stem cells will be isolated from duodenal biopsies collected from participants, followed by differentiation into mini-guts. Genome-wide genetic screening for host essential and restrictive factors will be performed on infected mini-guts by knockout CRISPR and gain-of-function CRISPR SAM, respectively. Shortlisted candidates will undergo preliminary functional validation in cell lines. These data will provide insights into potential therapeutic targets against norovirus infection.