Overcoming host restrictions to enable continuous passaging of human noroviruses in human intestinal enteroids.

Human noroviruses (HuNoVs), the leading cause of viral gastroenteritis, can now be cultivated in human intestinal enteroids (HIEs). However, indefinite passaging of HuNoVs in HIEs remained a challenge, necessitating the use of patient stool samples as viral inocula. Using RNA-seq, we identified host restriction factors that might limit viral passaging.

Macrophage phagocytosis of human norovirus-infected cells in an human enteroid-macrophage coculture model.

Human norovirus (HuNoV) causes acute gastroenteritis in immunocompetent hosts and chronic infection in immunocompromised individuals. Many recent studies of replication and innate immune responses following HuNoV infection have utilized epithelium-only human intestinal enteroids (HIEs), which lack immune cells. Here, we utilized an enteroid-macrophage coculture model consisting of HIEs and different subtypes of human peripheral blood mononuclear cell-derived macrophages to better recapitulate gut biology and explore the role of macrophages in HuNoV replication and pathogenesis.

Complete genomic characterization of global pathogens respiratory syntical virus and human norovirus using probe based capture enrichment.

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in children worldwide, while human noroviruses (HuNoV) are a leading cause of epidemic and sporadic acute gastroenteritis. Generating full-length genome sequences for these viruses is crucial for understanding viral diversity and tracking emerging variants. However, obtaining high-quality sequencing data is often challenging due to viral strain variability, quality, and low titers.

BTP2 restricts Tulane virus and human norovirus replication independent of store-operated calcium entry.

Human norovirus is the leading cause of viral gastroenteritis across all age groups. While there is a need for human norovirus antivirals, therapeutic development has been hindered by a lack of cell culture systems and animal models of infection. Surrogate viruses, such as Tulane virus (TV), have provided tractable systems to screen potential antiviral compounds.

The CRAC channel inhibitor BTP2 restricts Tulane virus and human norovirus replication independent of store-operated calcium entry.

Unlabelled: Human norovirus is the leading cause of viral gastroenteritis across all age groups. While there is a need for human norovirus antivirals, therapeutic development has been hindered by a lack of cell culture systems and animal models of infection. Surrogate viruses, such as Tulane virus (TV), have provided tractable systems to screen potential antiviral compounds.

Conformational flexibility is a critical factor in designing broad-spectrum human norovirus protease inhibitors.

Unlabelled: Human norovirus (HuNoV) is a leading cause of gastroenteritis worldwide and is associated with significant morbidity, mortality, and economic impact. There are currently no licensed antiviral drugs for the treatment of HuNoV-associated gastroenteritis. The HuNoV protease plays a critical role in the initiation of virus replication by cleaving the polyprotein.

Norovirus replication, host interactions and vaccine advances.

Human noroviruses (HuNoVs) are the leading cause of acute gastroenteritis worldwide in all age groups and cause significant disease and economic burden globally. To date, no approved vaccines or antiviral therapies are available to treat or prevent HuNoV illness. Several candidate vaccines are in clinical trials, although potential barriers to successful development must be overcome.

2'-Fucosyllactose inhibits human norovirus replication in human intestinal enteroids.

Unlabelled: Human noroviruses (HuNoVs) are the leading cause of acute gastroenteritis worldwide. Currently, there are no targeted antivirals for the treatment of HuNoV infection. Histo-blood group antigens (HBGAs) on the intestinal epithelium are cellular attachment factors for HuNoVs; molecules that block the binding of HuNoVs to HBGAs thus have the potential to be developed as antivirals.

Geographic disparities impacting oral vaccine performance: Observations and future directions.

Oral vaccines have several advantages compared with parenteral administration: they can be relatively cheap to produce in high quantities, easier to administer, and induce intestinal mucosal immunity that can protect against infection. These characteristics have led to successful use of oral vaccines against rotavirus, polio, and cholera. Unfortunately, oral vaccines for all three diseases have demonstrated lower performance in the highest-burden settings where they are most needed.

Lack of Detection of Norwalk Virus in Saliva Samples From a Controlled Human Infection Model.

Following recent reports of norovirus replication in salivary gland cells, we examined whether the prototype norovirus strain, Norwalk virus (GI.1), could be detected in the saliva of 21 experimentally infected persons. Viral RNA was not detected in saliva 2 and 7 days after challenge despite high levels being present in feces.

CONFORMATIONAL FLEXIBILITY IS A CRITICAL FACTOR IN DESIGNING BROAD-SPECTRUM HUMAN NOROVIRUS PROTEASE INHIBITORS.

Human norovirus (HuNoV) infection is a global health and economic burden. Currently, there are no licensed HuNoV vaccines or antiviral drugs available. The protease encoded by the HuNoV genome plays a critical role in virus replication by cleaving the polyprotein and is, therefore, an excellent target for developing small molecule inhibitors.

INTRA- AND INTER-HOST EVOLUTION OF HUMAN NOROVIRUS IN HEALTHY ADULTS.

Background: Human noroviruses are a leading cause of acute and sporadic gastroenteritis worldwide. The evolution of human noroviruses in immunocompromised persons has been evaluated in many studies. Much less is known about the evolutionary dynamics of human norovirus in healthy adults.

Select Gut Microbiota Impede Rotavirus Vaccine Efficacy.

Background & Aims: The protection provided by rotavirus (RV) vaccines is highly heterogeneous among individuals. We hypothesized that microbiota composition might influence RV vaccine efficacy.

Methods: First, we examined the potential of segmented filamentous bacteria (SFB) colonization to influence RV vaccine efficacy in mice.

MFGM-enriched whey displays antiviral activity against common pediatric viruses .

Background: Among the most common mucosal viral infections in infants are rotavirus, one of the main causes of severe gastroenteritis in infants and children up to 5 years, and respiratory syncytial virus (RSV), one of the leading causes of lower respiratory tract infections. Both human milk and bovine milk derived factors may provide protection against mucosal viral infections. More recently, a similar activity of milk derived proteins was suggested for SARS-CoV-2.

Infant and adult human intestinal enteroids are morphologically and functionally distinct.

Unlabelled: Human intestinal enteroids (HIEs) are gaining recognition as physiologically relevant models of the intestinal epithelium. While HIEs from adults are used extensively in biomedical research, few studies have used HIEs from infants. Considering the dramatic developmental changes that occur during infancy, it is important to establish models that represent infant intestinal characteristics and physiological responses.

Gut-resident C. perfringens impedes rotavirus vaccine efficacy.

Background & Aims: The extent to which live orally-administered rotavirus (RV) vaccines elicit protective immunity is highly heterogeneous. We hypothesized microbiota composition might influence vaccine efficacy.

Methods: We tested this concept by examining extent to which colonizing mice with segmented filamentous bacteria (SFB) influenced RV vaccine efficacy.

Correlation of Genogroup I, Genotype 1 (GI.1) Norovirus Neutralizing Antibody Levels With GI.1 Histo-Blood Group Antigen-Blocking Antibody Levels.

Background: The in vitro cultivation of human noroviruses allows a comparison of antibody levels measured in neutralization and histo-blood group antigen (HBGA)-blocking assays.

Methods: Serum samples collected during the evaluation of an investigational norovirus vaccine (HIL-214 [formerly TAK-214]) were assayed for neutralizing antibody levels against the vaccine's prototype Norwalk virus/genogroup I, genotype 1 (GI.1) (P1) virus strain.

Divergent responses of human intestinal organoid monolayers using commercial in vitro cytotoxicity assays.

In vitro models, such as primary cells and continuous cell lines routinely used for evaluating drug candidates, have limitations in their translational relevance to human diseases. Organotypic cultures are increasingly being used to assess therapeutics for various cancers and infectious diseases. Monitoring drug cytotoxicity in cell cultures is crucial in drug development, and several commercially available kits for cytotoxicity assessment offer distinct advantages and limitations.

2'-Fucosyllactose Inhibits Human Norovirus Replication in Human Intestinal Enteroids.

Human noroviruses (HuNoVs) are the leading cause of acute gastroenteritis worldwide. Currently, there are no targeted antivirals for the treatment of HuNoV infection. Histo-blood group antigens (HBGAs) on the intestinal epithelium are cellular attachment factors for HuNoVs; molecules that block the binding of HuNoVs to HBGAs thus have the potential to be developed as antivirals.

Insights into Human Norovirus Cultivation in Human Intestinal Enteroids.

Unlabelled: Human noroviruses (HuNoVs) are a significant cause of epidemic and sporadic acute gastroenteritis worldwide. The lack of a reproducible culture system hindered the study of HuNoV replication and pathogenesis for almost a half-century. This barrier was overcome with our successful cultivation of multiple HuNoV strains in human intestinal enteroids (HIEs), which has significantly advanced HuNoV research.

Analyzing efficiency of a lentiviral shRNA knockdown system in human enteroids using western blot and flow cytometry.

Enteroids are in vitro models to study gastrointestinal pathologies and test personalized therapeutics; however, the inherent complexity of enteroids often renders standard gene editing approaches ineffective. Here, we introduce a refined lentiviral transfection protocol, ensuring sufficient lentiviral engagement with enteroids while considering spatiotemporal growth variability throughout the extracellular matrix. Additionally, we highlight a selection process for transduced cells, introduce a protocol to accurately measure transduction efficiency, and explore methodologies to gauge effects of gene knockdown on biological processes.