Exploring host-commensal-pathogen dynamics in cell line and organotypic human intestinal epithelial models.

Host and microbiome intricately interact in the ecosystem of the human digestive tract, playing a crucial role in our health. These interactions can initiate immune responses in the epithelial cells, which, in turn, activate downstream responses in other immune cells. Here, we used a CaCo-2 and a human intestinal enteroid (HIE) model to explore epithelial responses to both commensal and pathogenic bacteria, individually and combined. CaCo-2 cells were co-cultured with peripheral blood mononuclear cells, revealing downstream activation of immune cells. While both systems showed comparable cytokine profiles, they differed in their responses to the different bacteria, with the organoid system being more representative of responses observed in humans. We provide evidence of the pro-inflammatory responses associated with these bacteria. These models contribute to a deeper understanding of the interactions between the microbiota, intestinal epithelium, and immune cells in the gut, promoting advances in the field of host-microbe interactions.

Parechovirus infection in human brain organoids: host innate inflammatory response and not neuro-infectivity correlates to neurologic disease.

Picornaviruses are a leading cause of central nervous system (CNS) infections. While genotypes such as parechovirus A3 (PeV-A3) and echovirus 11 (E11) can elicit severe neurological disease, the highly prevalent PeV-A1 is not associated with CNS disease. Here, we expand our current understanding of these differences in PeV-A CNS disease using human brain organoids and clinical isolates of the two PeV-A genotypes. Our data indicate that PeV-A1 and A3 specific differences in neurological disease are not due to infectivity of CNS cells as both viruses productively infect brain organoids with a similar cell tropism. Proteomic analysis shows that PeV-A infection significantly alters the host cell metabolism. The inflammatory response following PeV-A3 (and E11 infection) is significantly more potent than that upon PeV-A1 infection. Collectively, our findings align with clinical observations and suggest a role for neuroinflammation, rather than viral replication, in PeV-A3 (and E11) infection.

The combination of pleconaril, rupintrivir, and remdesivir efficiently inhibits enterovirus infections in vitro, delaying the development of drug-resistant virus variants.

Enteroviruses are a significant global health concern, causing a spectrum of diseases from the common cold to more severe conditions like hand-foot-and-mouth disease, meningitis, myocarditis, pancreatitis, and poliomyelitis. Current treatment options for these infections are limited, underscoring the urgent need for effective therapeutic strategies. To find better treatment option we analyzed toxicity and efficacy of 12 known broad-spectrum anti-enterovirals both individually and in combinations against different enteroviruses in vitro. We identified several novel, synergistic two-drug and three-drug combinations that demonstrated significant inhibition of enterovirus infections in vitro. Specifically, the triple-drug combination of pleconaril, rupintrivir, and remdesivir exhibited remarkable efficacy against echovirus (EV) 1, EV6, EV11, and coxsackievirus (CV) B5, in human lung epithelial A549 cells. This combination surpassed the effectiveness of single-agent or dual-drug treatments, as evidenced by its ability to protect A549 cells from EV1-induced cytotoxicity across seven passages. Additionally, this triple-drug cocktail showed potent antiviral activity against EV-A71 in human intestinal organoids. Thus, our findings highlight the therapeutic potential of the pleconaril-rupintrivir-remdesivir combination as a broad-spectrum treatment option against a range of enterovirus infections. The study also paves the way towards development of strategic antiviral drug combinations with virus family coverage and high-resistance barriers.

Assessment of the broad-spectrum host targeting antiviral efficacy of halofuginone hydrobromide in human airway, intestinal and brain organotypic models.

Halofuginone hydrobromide has shown potent antiviral efficacy against a variety of viruses such as SARS-CoV-2, dengue, or chikungunya virus, and has, therefore, been hypothesized to have broad-spectrum antiviral activity. In this paper, we tested this broad-spectrum antiviral activity of Halofuginone hydrobomide against viruses from different families (Picornaviridae, Herpesviridae, Orthomyxoviridae, Coronaviridae, and Flaviviridae). To this end, we used relevant human models of the airway and intestinal epithelium and regionalized neural organoids. Halofuginone hydrobomide showed antiviral activity against SARS-CoV-2 in the airway epithelium with no toxicity at equivalent concentrations used in human clinical trials but not against any of the other tested viruses.

Non-Polio Enterovirus C Replicate in Both Airway and Intestine Organotypic Cultures.

Non-polio enteroviruses (EV) belonging to species C, which are highly prevalent in Africa, mainly among children, are poorly characterized, and their pathogenesis is mostly unknown as they are difficult to culture. In this study, human airway and intestinal organotypic models were used to investigate tissue and cellular tropism of three EV-C genotypes, EV-C99, CVA-13, and CVA-20. Clinical isolates were obtained within the two passages of culture on Caco2 cells, and all three viruses were replicated in both the human airway and intestinal organotypic cultures. We did not observe differences in viral replication between fetal and adult tissue that could potentially explain the preferential infection of infants by EV-C genotypes. Infection of the airway and the intestinal cultures indicates that they both can serve as entry sites for non-polio EV-C. Ciliated airway cells and enterocytes are the target of infection for all three viruses, as well as enteroendocrine cells for EV-C99.

Amino acid variation at VP1-145 of enterovirus A71 determines the viral infectivity and receptor usage in a primary human intestinal model.

Enterovirus A71 (EV-A71) can elicit a wide variety of human diseases such as hand, foot, and mouth disease and severe or fatal neurological complications. It is not clearly understood what determines the virulence and fitness of EV-A71. It has been observed that amino acid changes in the receptor binding protein, VP1, resulting in viral binding to heparan sulfate proteoglycans (HSPGs) may be important for the ability of EV-A71 to infect neuronal tissue. In this study, we identified that the presence of glutamine, as opposed to glutamic acid, at VP1-145 is key for viral infection in a 2D human fetal intestinal model, consistent with previous findings in an airway organoid model. Moreover, pre-treatment of EV-A71 particles with low molecular weight heparin to block HSPG-binding significantly reduced the infectivity of two clinical EV-A71 isolates and viral mutants carrying glutamine at VP1-145. Our data indicates that mutations in VP1 leading to HSPG-binding enhances viral replication in the human gut. These mutations resulting in increased production of viral particles at the primary replication site could lead to a higher risk of subsequent neuroinfection. Importance: With the near eradication of polio worldwide, polio-like illness (as is increasingly caused by EV-A71 infections) is of emerging concern. EV-A71 is indeed the most neurotropic enterovirus that poses a major threat globally to public health and specifically in infants and young children. Our findings will contribute to the understanding of the virulence and the pathogenicity of this virus. Further, our data also supports the identification of potential therapeutic targets against severe EV-A71 infection especially among infants and young children. Furthermore, our work highlights the key role of HSPG-binding mutations in the disease outcome of EV-A71. Additionally, EV-A71 is not able to infect the gut (the primary replication site in humans) in traditionally used animal models. Thus, our research highlights the need for human-based models to study human viral infections.Graphical Abstract.

A beginner's guide on the use of brain organoids for neuroscientists: a systematic review.

BACKGROUND: The first human brain organoid protocol was presented in the beginning of the previous decade, and since then, the field witnessed the development of many new brain region-specific models, and subsequent protocol adaptations and modifications. The vast amount of data available on brain organoid technology may be overwhelming for scientists new to the field and consequently decrease its accessibility. Here, we aimed at providing a practical guide for new researchers in the field by systematically reviewing human brain organoid publications. METHODS: Articles published between 2010 and 2020 were selected and categorised for brain organoid applications. Those describing neurodevelopmental studies or protocols for novel organoid models were further analysed for culture duration of the brain organoids, protocol comparisons of key aspects of organoid generation, and performed functional characterisation assays. We then summarised the approaches taken for different models and analysed the application of small molecules and growth factors used to achieve organoid regionalisation. Finally, we analysed articles for organoid cell type compositions, the reported time points per cell type, and for immunofluorescence markers used to characterise different cell types. RESULTS: Calcium imaging and patch clamp analysis were the most frequently used neuronal activity assays in brain organoids. Neural activity was shown in all analysed models, yet network activity was age, model, and assay dependent. Induction of dorsal forebrain organoids was primarily achieved through combined (dual) SMAD and Wnt signalling inhibition. Ventral forebrain organoid induction was performed with dual SMAD and Wnt signalling inhibition, together with additional activation of the Shh pathway. Cerebral organoids and dorsal forebrain model presented the most cell types between days 35 and 60. At 84 days, dorsal forebrain organoids contain astrocytes and potentially oligodendrocytes. Immunofluorescence analysis showed cell type-specific application of non-exclusive markers for multiple cell types. CONCLUSIONS: We provide an easily accessible overview of human brain organoid cultures, which may help those working with brain organoids to define their choice of model, culture time, functional assay, differentiation, and characterisation strategies.

Global impact of COVID-19 on agriculture: role of sustainable agriculture and digital farming.

The rise and spread of the coronavirus pandemic (COVID-19) has created an imbalance in all sectors worldwide, massively disrupting the global economy. Social distancing, quarantine regulations, and strict travel restrictions have led to a major reduction in the workforce and loss of jobs across all industrial sectors. One of the sectors completely exposed was the agriculture and food sector. The initiation of a nationwide lockdown by the government resulted in the shutdown of industries globally impacting the overall supply chain from farmer to consumer. The need of the hour is to propose effective solutions which can serve the dual purpose of market growth as well as customer satisfaction. This paper reviews the impact of COVID-19 on the agro-food system and its economy stressing critical factors like food production, demand, price hikes, security, and supply chain resilience. To conserve natural resources and meet the sustainable development goals (SDG), importance has been given to adopting sustainable agricultural practices with a prime focus on techniques like urban agriculture, crop rotation, hydroponics, and family farming. Possible advancements like the use of digital tools, mainly artificial intelligence, machine learning, deep learning, and block-chain technology, in the agro-food sector have been discussed as they could be a promising tool to develop a self-reliant society. This work would be a perfect platform to understand the growing impact of the pandemic as well as supporting cost-effective solutions for a green ecosystem.

Human Dendritic Cells Transmit Enterovirus A71 via Heparan Sulfates to Target Cells Independent of Viral Replication.

Enterovirus A71 (EV-A71) is a causative agent of life-threatening neurological diseases in young children. EV-A71 is highly infectious but it remains unclear how the virus disseminates from primary entry sites-the mucosa of the respiratory tract or the intestine-to secondary replication sites-skin or brain. Here, we investigated the role of dendritic cells (DCs) in EV-A71 dissemination. DCs reside in the mucosa of the airway and gut, and migrate to lymphoid tissues upon activation and, therefore, could facilitate EV-A71 dissemination to secondary replication sites. Monocyte-derived DCs were not permissive to different genotypes of EV-A71 but, notably, coculture with EV-A71-susceptiblle RD99 cells led to very efficient infection of RD99 cells. Notably, EV-A71 transmission of DCs to RD99 was independent of viral replication as a replication inhibitor did not affect transmission. Soluble heparin blocked EV-A71 transmission by DCs to RD99 cells, in contrast to antibodies against known attachment receptor DC-SIGN. These results strongly suggest that DCs might be a first target for EV-A71 and involved in viral dissemination via heparan sulfates and heparin derivatives might be an effective treatment to attenuate dissemination. IMPORTANCE EV-A71 is an emerging neurotropic virus that is of emerging concern and can result in polio-like illness. The exact mechanism of how EV-A71 results in neurological symptoms are unknown. In particular, the early dissemination of the virus from primary replication sites (airway and intestine) to secondary sites (central nervous system and skin) needs to be elucidated. There is evidence pointing toward a role for dendritic cells (DC) in EV-A71 transmission. Moreover, heparan sulfate (HS) binding mutations are observed in patients with severe diseases. Therefore, we evaluated the potential role of HS on DC in transmission. We find that HS are critical for transmitting EV-A71 by DC to target cells. Our data are consistent with other clinical and in vitro observations highlighting the importance of HS in EV-A71-induced disease.

Enterovirus D68 Infection in Human Primary Airway and Brain Organoids: No Additional Role for Heparan Sulfate Binding for Neurotropism.

Enterovirus D68 (EV-D68) is an RNA virus that can cause outbreaks of acute flaccid paralysis (AFP), a polio-like disease. Before 2010, EV-D68 was a rare pathogen associated with mild respiratory symptoms, but the recent EV-D68 related increase in severe respiratory illness and outbreaks of AFP is not yet understood. An explanation for the rise in severe disease is that it may be due to changes in the viral genome resulting in neurotropism. In this regard, in addition to sialic acid, binding to heparan sulfate proteoglycans (HSPGs) has been identified as a feature for viral entry of some EV-D68 strains in cell lines. Studies in human primary organotypic cultures that recapitulate human physiology will address the relevance of these HSPG-binding mutations for EV-D68 infection in vivo. Therefore, in this work, we studied the replication and neurotropism of previously determined sialic acid-dependent and HSPG-dependent strains using primary human airway epithelial (HAE) cultures and induced human pluripotent stem cell (iPSC)-derived brain organoids. All three strains (B2/2042, B2/947, and A1/1348) used in this study infected HAE cultures and human brain organoids (shown for the first time). Receptor-blocking experiments in both cultures confirm that B2/2042 infection is solely dependent on sialic acid, while B2/947 and A1/1348 (HSPG to a lesser extent) binds to sialic acid and HSPG for cell entry. Our data suggest that HSPG-binding can be used by EV-D68 for entry in human physiological models but offers no advantage for EV-D68 infection of brain cells. IMPORTANCE Recent outbreaks of enterovirus D68, a nonpolio enterovirus, is associated with a serious neurological condition in young children, acute flaccid myelitis (AFM). As there is no antiviral treatment or vaccine available for EV-D68 it is important to better understand how EV-D68 causes AFM and why only recent outbreaks are associated with AFM. We investigated if a change in receptor usage of EV-D68 increases the virulence of EV-D68 in the airway or the central nervous system and thus could explain the increase in AFM cases. We studied this using physiologically relevant human airway epithelium and cerebral organoid cultures that are physiologically relevant human models. Our data suggest that heparan sulfate proteoglycans can be used by EV-D68 as an additional entry receptor in human physiological models but offers no advantage for EV-D68 infection of brain cells, and our data show the potential of these 46 innovative models for virology.

Human milk inhibits some enveloped virus infections, including SARS-CoV-2, in an intestinal model.

Human milk is important for antimicrobial defense in infants and has well demonstrated antiviral activity. We evaluated the protective ability of human milk against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a human fetal intestinal cell culture model. We found that, in this model, human milk blocks SARS-CoV-2 replication, irrespective of the presence of SARS-CoV-2 spike-specific antibodies. Complete inhibition of both enveloped Middle East respiratory syndrome coronavirus and human respiratory syncytial virus infections was also observed, whereas no inhibition of non-enveloped enterovirus A71 infection was seen. Transcriptome analysis after 24 h of the intestinal monolayers treated with human milk showed large transcriptomic changes from human milk treatment, and subsequent analysis suggested that <i>ATP1A1</i> down-regulation by milk might be of importance. Inhibition of ATP1A1 blocked SARS-CoV-2 infection in our intestinal model, whereas no effect on EV-A71 infection was seen. Our data indicate that human milk has potent antiviral activity against particular (enveloped) viruses by potentially blocking the ATP1A1-mediated endocytic process.

Extraction techniques in food industry: Insights into process parameters and their optimization.

This review presents critical evaluation of the key parameters that affect the extraction of targeted components, giving due consideration to safety and environmental aspects. The crucial aspects of the extraction technologies along with protocols and process parameters for designing unit operations have been emphasized. The parameters like solvent usage, substrate type, concentration, particle size, temperature, quality and storage of extract as well as stability of extraction have been elaborately discussed. The process optimization using mathematical and computational modeling highlighting information and communication technologies have been given importance aiming for a green and sustainable industry level scaleup. The findings indicate that the extraction processes vary significantly depending on the category of food and its structure. There is no single extraction method or universal set of process conditions identified for extracting all value-added products from respective sources. A comprehensive understanding of process parameters and their optimization as well as synergistic combination of multiple extraction processes can aid in enhancement of the overall extraction efficiency. Future efforts must be directed toward the design of integrated unit operations that cause minimal harm to the environment along with investigations on economic feasibility to ensure sustainable extraction systems.

Apical-out airway organoids as a platform for studying viral infections and screening for antiviral drugs.

Airway organoids are polarized 3D epithelial structures that recapitulate the organization and many of the key functions of the in vivo tissue. They present an attractive model that can overcome some of the limitations of traditional 2D and Air-Liquid Interface (ALI) models, yet the limited accessibility of the organoids' apical side has hindered their applications in studies focusing on host-pathogen interactions. Here, we describe a scalable, fast and efficient way to generate airway organoids with the apical side externally exposed. These apical-out airway organoids are generated in an Extracellular Matrix (ECM)-free environment from 2D-expanded bronchial epithelial cells and differentiated in suspension to develop uniformly-sized organoid cultures with robust ciliogenesis. Differentiated apical-out airway organoids are susceptible to infection with common respiratory viruses and show varying responses upon treatment with antivirals. In addition to the ease of apical accessibility, these apical-out airway organoids offer an alternative in vitro model to study host-pathogen interactions in higher throughput than the traditional air-liquid interface model.

Human Brain Organoids as Models for Central Nervous System Viral Infection.

Pathogenesis of viral infections of the central nervous system (CNS) is poorly understood, and this is partly due to the limitations of currently used preclinical models. Brain organoid models can overcome some of these limitations, as they are generated from human derived stem cells, differentiated in three dimensions (3D), and can mimic human neurodevelopmental characteristics. Therefore, brain organoids have been increasingly used as brain models in research on various viruses, such as Zika virus, severe acute respiratory syndrome coronavirus 2, human cytomegalovirus, and herpes simplex virus. Brain organoids allow for the study of viral tropism, the effect of infection on organoid function, size, and cytoarchitecture, as well as innate immune response; therefore, they provide valuable insight into the pathogenesis of neurotropic viral infections and testing of antivirals in a physiological model. In this review, we summarize the results of studies on viral CNS infection in brain organoids, and we demonstrate the broad application and benefits of using a human 3D model in virology research. At the same time, we describe the limitations of the studies in brain organoids, such as the heterogeneity in organoid generation protocols and age at infection, which result in differences in results between studies, as well as the lack of microglia and a blood brain barrier.

Neutrophil Extracellular Traps Do Not Induce Injury and Inflammation in Well-Differentiated RSV-Infected Airway Epithelium.

Respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI) causes a major burden of disease. The host response in RSV-LRTI is characterized by airway epithelial injury, inflammation and neutrophil influx, with the formation of neutrophil extracellular traps (NETs). However, the precise role of NETs in the pathophysiology of RSV-LRTI remains to be elucidated. Here, we used well-differentiated human airway epithelial cultures (HAE) of a pediatric and adult donor to study whether NETs cause airway epithelial injury and inflammation in the setting of RSV infection. The exposure of uninfected and RSV-infected HAE cultures to NETs, as produced by stimulation of neutrophils by a low dose of phorbol 12-myristate 13-acetate (PMA), did not induce or aggravate cell injury or inflammation. RSV infection of HAE cultures caused release of pro-inflammatory cytokines such as IL-6 and RANTES in both adult and pediatric cultures, but the differential gene expression for regulated cell death differed between culture donors. In this in vitro airway epithelial model, NETs in the setting of RSV infection did not cause or aggravate epithelial injury or inflammation.

Valorization of food waste as adsorbents for toxic dye removal from contaminated waters: A review.

Industrial contaminants such as dyes and intermediates are released into water bodies, making the water unfit for human use. At the same time large amounts of food wastes accumulate near the work places, residential complexes etc. polluting the air due to putrefaction. The need of the hour lies in finding innovative solutions for dye removal from wastewater streams. In this context, the article emphasizes adoption or conversion of food waste materials, an ecological nuisance, as adsorbents for the removal of dyes from wastewaters. Adsorption, being a well-established technique, the review critically examines the specific potential of food waste constituents as dye adsorbents. The efficacy of food waste-based adsorbents is examined, besides addressing the possible adsorption mechanisms and the factors affecting phenomenon such as pH, temperature, contact time, adsorbent dosage, particle size, and ionic strength. Integration of information and communication technology approaches with adsorption isotherms and kinetic models are emphasized to bring out their role in improving overall modeling performance. Additionally, the reusability of adsorbents has been highlighted for effective substrate utilization. The review makes an attempt to stress the valorization of food waste materials to remove dyes from contaminated waters thereby ensuring long-term sustainability.

Utilization of fruit and vegetable waste to produce value-added products: Conventional utilization and emerging opportunities-A review.

Fruit and vegetables are one of the most consumed commodities globally, accounting for more than 42% of total food wastage. These vegetal foods can be consumed raw, processed, or taken as an addition to other food items. The continuous rise in population, in addition to technological advancements, has led to an imbalance in demand supply, resulting in increased food wastage globally. Although source reduction and recycling have shown promising results, more evaluations concerning economics and environmental impacts need to be given importance. The need of the hour lies in finding a possible method towards effective utilization for fruit and vegetable waste to generate value-added products which are more eco-friendly, cheaper, and sustainable. Thus, this article attempts to focus on the conventional and emerging opportunities of fruit and vegetable waste to generate value-added products. Conventional utilization, namely briquetting, waste to energy conversion, enzymatic degradation, and adsorption, as well as emerging opportunities in the areas of nutraceuticals, packaging, flavoring agents, and waste induced nanoparticles, have been emphasized. Additionally, recommendations and future perspectives towards better utilization of vegetal waste have been given importance. This review aims to narrow down the path towards evaluating the most techno-economic and efficient waste management technique for fruits and vegetable valorization, which can be promoted in the long term.

Extraction and detection methods of microplastics in food and marine systems: A critical review.

The ubiquitous presence of microplastics as contaminants in the ecosystem has become a matter of environmental concern gaining considerable attention in the research community as well as public arena. Lack of efficient collection and improper management of plastic have resulted in the enormous amounts of plastic wastes landing into the marine systems with oceans being the ultimate sink. Due to non-biodegradability, these plastics break down into smaller fragments over a period of time leading to consumption by aquatic species, threatening marine life. In the recent years, a wide range of food products has also been contaminated with microplastics directly affecting human health. This review focuses on the separation and identification technologies for extraction and detection of microplastics in food and marine ecosystems. Efficient technologies like floatation, membrane separation, chemical treatment, enzymatic treatment, and other miscellaneous techniques have been discussed considering their merits and demerits. Additionally, identification technologies like optical detection, scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, thermo-analytical methods, and hyperspectral imaging have been emphasized for the detection of microplastic particles. The emerging techniques like enzymatic digestion combined with hyperspectral imaging could be a possible way for obtaining higher separation efficiency and characterization with minimal harm to food sample. This article narrows the gap for choosing a standard separation technology for microplastic detection in food matrices keeping in mind the composition, particle size, shape, data visualization techniques and cost.

Lab-on-a-chip technologies for food safety, processing, and packaging applications: a review.

The advent of microfluidic systems has led to significant developments in lab-on-a-chip devices integrating several functions onto a single platform. Over the years, these miniature devices have become a promising tool for faster analytical testing, displaying high precision and efficiency. Nonetheless, most microfluidic systems are not commercially available. Research is actually undergoing on the application of these devices in environmental, food, biomedical, and healthcare industries. The lab-on-a-chip industry is predicted to grow annually by 20%. Here, we review the use of lab-on-a-chip devices in the food sector. We present fabrication technologies and materials to developing lab-on-a-chip devices. We compare electrochemical, optical, colorimetric, chemiluminescence and biological methods for the detection of pathogens and microorganisms. We emphasize emulsion processing, food formulation, nutraceutical development due to their promising characteristics. Last, smart packaging technologies like radio frequency identification and indicators are highlighted because they allow better product identification and traceability.

Parechovirus A Infection of the Intestinal Epithelium: Differences Between Genotypes A1 and A3.

Human parechovirus (PeV-A), one of the species within the Picornaviridae family, is known to cause disease in humans. The most commonly detected genotypes are PeV-A1, associated with mild gastrointestinal disease in young children, and PeV-A3, linked to severe disease with neurological symptoms in neonates. As PeV-A are detectable in stool and nasopharyngeal samples, entry is speculated to occur via the respiratory and gastro-intestinal routes. In this study, we characterized PeV-A1 and PeV-A3 replication and tropism in the intestinal epithelium using a primary 2D model based on human fetal enteroids. This model was permissive to infection with lab-adapted strains and clinical isolates of PeV-A1, but for PeV-A3, infection could only be established with clinical isolates. Replication was highest with infection established from the basolateral side with apical shedding for both genotypes. Compared to PeV-A1, replication kinetics of PeV-A3 were slower. Interestingly, there was a difference in cell tropism with PeV-A1 infecting both Paneth cells and enterocytes, while PeV-A3 infected mainly goblet cells. This difference in cell tropism may explain the difference in replication kinetics and associated disease in humans.