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1.
Cytokine ; 152: 155826, 2022 04.
Article in English | MEDLINE | ID: covidwho-1693705

ABSTRACT

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of the newly emerging lung disease pandemic COVID-19. This viral infection causes a series of respiratory disorders, and although this virus mainly infects respiratory cells, the small intestine can also be an important site of entry or interaction, as enterocytes highly express in angiotensin-2 converting enzyme (ACE) receptors. There are countless reports pointing to the importance of interferons (IFNs) with regard to the mediation of the immune system in viral infection by SARS-CoV-2. Thus, this review will focus on the main cells that make up the large intestine, their specific immunology, as well as the function of IFNs in the intestinal mucosa after the invasion of coronavirus-2.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , Intestinal Mucosa/metabolism , Intestine, Large/metabolism , SARS-CoV-2/metabolism , COVID-19/pathology , Humans , Intestinal Mucosa/injuries , Intestinal Mucosa/pathology , Intestinal Mucosa/virology , Intestine, Large/injuries , Intestine, Large/pathology , Intestine, Large/virology
2.
Front Immunol ; 12: 674074, 2021.
Article in English | MEDLINE | ID: covidwho-1551497

ABSTRACT

As a new infectious disease, COVID-19 is spread through the respiratory tract in most cases. Its source and pathological mechanism are not clear. The most common clinical feature is pulmonary infection. Also, a lot patients have gastrointestinal symptoms. Angiotensin-converting enzyme 2 (ACE2) is a functional cellular receptor for SARS-CoV-2, which is like SARS-CoV, a coronavirus associated with severe acute respiratory syndrome (SARS) outbreak in 2003. The tissues and cells expressing ACE2 are potential targets for SARS-CoV-2 infection, and the high expression of ACE2 in intestinal epithelial cells marks that SARS-CoV-2 may directly infect intestinal epithelial cells. Recent studies also suggest that SARS-CoV-2 existed and replicated in intestinal environment for a long time. The interaction between SARS-CoV-2 and RAS system leads to the decrease of local anti-inflammatory ability. The virus cycle leads to excessive imbalance of immune response and cytokine release. The downregulation of ACE2 after viral infection leads to gastrointestinal dysfunction. The above are the causes of gastrointestinal symptoms. Here, we reviewed the possible causes and mechanisms of gastrointestinal symptoms caused by COVID-19. Additionally, we discussed the influence of gastrointestinal symptoms on the prognosis of patients.


Subject(s)
COVID-19/virology , Intestinal Mucosa/virology , SARS-CoV-2/pathogenicity , Humans
3.
Nat Commun ; 12(1): 6610, 2021 11 16.
Article in English | MEDLINE | ID: covidwho-1521737

ABSTRACT

COVID-19 typically manifests as a respiratory illness, but several clinical reports have described gastrointestinal symptoms. This is particularly true in children in whom gastrointestinal symptoms are frequent and viral shedding outlasts viral clearance from the respiratory system. These observations raise the question of whether the virus can replicate within the stomach. Here we generate gastric organoids from fetal, pediatric, and adult biopsies as in vitro models of SARS-CoV-2 infection. To facilitate infection, we induce reverse polarity in the gastric organoids. We find that the pediatric and late fetal gastric organoids are susceptible to infection with SARS-CoV-2, while viral replication is significantly lower in undifferentiated organoids of early fetal and adult origin. We demonstrate that adult gastric organoids are more susceptible to infection following differentiation. We perform transcriptomic analysis to reveal a moderate innate antiviral response and a lack of differentially expressed genes belonging to the interferon family. Collectively, we show that the virus can efficiently infect the gastric epithelium, suggesting that the stomach might have an active role in fecal-oral SARS-CoV-2 transmission.


Subject(s)
COVID-19/pathology , Intestinal Mucosa/virology , Organoids/virology , SARS-CoV-2/physiology , Stomach/virology , Virus Replication/physiology , Aborted Fetus , Aged , Animals , COVID-19/virology , Cell Line , Child , Child, Preschool , Chlorocebus aethiops , Humans , Infant , Intestinal Mucosa/pathology , Middle Aged , Organoids/pathology , SARS-CoV-2/isolation & purification , Stomach/pathology
4.
Front Immunol ; 12: 636966, 2021.
Article in English | MEDLINE | ID: covidwho-1438414

ABSTRACT

Since 2003, the world has been confronted with three new betacoronaviruses that cause human respiratory infections: SARS-CoV, which causes severe acute respiratory syndrome (SARS), MERS-CoV, which causes Middle East respiratory syndrome (MERS), and SARS-CoV-2, which causes Coronavirus Disease 2019 (COVID-19). The mechanisms of coronavirus transmission and dissemination in the human body determine the diagnostic and therapeutic strategies. An important problem is the possibility that viral particles overcome tissue barriers such as the intestine, respiratory tract, blood-brain barrier, and placenta. In this work, we will 1) consider the issue of endocytosis and the possibility of transcytosis and paracellular trafficking of coronaviruses across tissue barriers with an emphasis on the intestinal epithelium; 2) discuss the possibility of antibody-mediated transcytosis of opsonized viruses due to complexes of immunoglobulins with their receptors; 3) assess the possibility of the virus transfer into extracellular vesicles during intracellular transport; and 4) describe the clinical significance of these processes. Models of the intestinal epithelium and other barrier tissues for in vitro transcytosis studies will also be briefly characterized.


Subject(s)
Endocytosis , Intestinal Mucosa/virology , SARS-CoV-2/metabolism , Antibodies, Viral/metabolism , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , COVID-19/drug therapy , COVID-19/transmission , COVID-19/virology , Clinical Trials as Topic , Endocytosis/drug effects , Humans , Intestinal Mucosa/metabolism , Models, Biological , SARS-CoV-2/drug effects , SARS-CoV-2/immunology , Tight Junctions/metabolism , Tight Junctions/virology , Transcytosis/drug effects , Virus Attachment
6.
Clin Dermatol ; 38(6): 750-756, 2020.
Article in English | MEDLINE | ID: covidwho-1385291

ABSTRACT

Pemphigus and its variants, viz., vulgaris, foliaceous, vegetans, Ig A pemphigus, paraneoplastic pemphigus and Senear-Usher syndrome are rare autoimmune blistering diseases of the skin and/or mucous membranes. The autoantibodies involved in the pathogenesis of pemphigus against desmoglein result in the breach of the skin and mucosal barrier, which acts as the first line of defence against pathogens. In this paper we underscore the importance of the integumentary system as a shield against the acquisition as well as transmission of SARS-CoV-2 virion. We have also made an attempt to delineate the various treatment modalities available and the viral-drug dynamics involved in choosing the optimum therapeutic modality.


Subject(s)
Adrenal Cortex Hormones/therapeutic use , COVID-19/transmission , Pemphigus/drug therapy , Virus Shedding , Administration, Oral , Adrenal Cortex Hormones/adverse effects , COVID-19/complications , Feces/virology , Humans , Intestinal Mucosa/drug effects , Intestinal Mucosa/virology , Mouth Mucosa/virology , Pemphigus/complications , Risk Factors , SARS-CoV-2 , Virus Shedding/drug effects
7.
JCI Insight ; 6(16)2021 08 23.
Article in English | MEDLINE | ID: covidwho-1369457

ABSTRACT

SARS-CoV-2 infects epithelial cells of the human gastrointestinal (GI) tract and causes related symptoms. HIV infection impairs gut homeostasis and is associated with an increased risk of COVID-19 fatality. To investigate the potential link between these observations, we analyzed single-cell transcriptional profiles and SARS-CoV-2 entry receptor expression across lymphoid and mucosal human tissue from chronically HIV-infected individuals and uninfected controls. Absorptive gut enterocytes displayed the highest coexpression of SARS-CoV-2 receptors ACE2, TMPRSS2, and TMPRSS4, of which ACE2 expression was associated with canonical interferon response and antiviral genes. Chronic treated HIV infection was associated with a clear antiviral response in gut enterocytes and, unexpectedly, with a substantial reduction of ACE2 and TMPRSS2 target cells. Gut tissue from SARS-CoV-2-infected individuals, however, showed abundant SARS-CoV-2 nucleocapsid protein in both the large and small intestine, including an HIV-coinfected individual. Thus, upregulation of antiviral response genes and downregulation of ACE2 and TMPRSS2 in the GI tract of HIV-infected individuals does not prevent SARS-CoV-2 infection in this compartment. The impact of these HIV-associated intestinal mucosal changes on SARS-CoV-2 infection dynamics, disease severity, and vaccine responses remains unclear and requires further investigation.


Subject(s)
Angiotensin-Converting Enzyme 2/analysis , HIV Infections/virology , Intestinal Mucosa/virology , SARS-CoV-2/isolation & purification , Serine Endopeptidases/analysis , Adult , Chronic Disease , Female , Humans , Intestinal Mucosa/chemistry , Male , Middle Aged
8.
Mucosal Immunol ; 14(6): 1381-1392, 2021 11.
Article in English | MEDLINE | ID: covidwho-1366810

ABSTRACT

The SARS-CoV-2 pandemic has so far claimed over three and a half million lives worldwide. Though the SARS-CoV-2 mediated disease COVID-19 has first been characterized by an infection of the upper airways and the lung, recent evidence suggests a complex disease including gastrointestinal symptoms. Even if a direct viral tropism of intestinal cells has recently been demonstrated, it remains unclear, whether gastrointestinal symptoms are caused by direct infection of the gastrointestinal tract by SARS-CoV-2 or whether they are a consequence of a systemic immune activation and subsequent modulation of the mucosal immune system. To better understand the cause of intestinal symptoms we analyzed biopsies of the small intestine from SARS-CoV-2 infected individuals. Applying qRT-PCR and immunohistochemistry, we detected SARS-CoV-2 RNA and nucleocapsid protein in duodenal mucosa. In addition, applying imaging mass cytometry and immunohistochemistry, we identified histomorphological changes of the epithelium, which were characterized by an accumulation of activated intraepithelial CD8+ T cells as well as epithelial apoptosis and subsequent regenerative proliferation in the small intestine of COVID-19 patients. In summary, our findings indicate that intraepithelial CD8+ T cells are activated upon infection of intestinal epithelial cells with SARS-CoV-2, providing one possible explanation for gastrointestinal symptoms associated with COVID-19.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Duodenum/immunology , Immunity, Mucosal , Intestinal Diseases/immunology , Intestinal Mucosa/immunology , Intraepithelial Lymphocytes/immunology , Lymphocyte Activation , SARS-CoV-2/immunology , Adult , Aged , Animals , Apoptosis , CD8-Positive T-Lymphocytes/virology , COVID-19/pathology , COVID-19/virology , Case-Control Studies , Cell Proliferation , Chlorocebus aethiops , Duodenum/pathology , Duodenum/virology , Female , Host-Pathogen Interactions , Humans , Intestinal Diseases/pathology , Intestinal Diseases/virology , Intestinal Mucosa/pathology , Intestinal Mucosa/virology , Intraepithelial Lymphocytes/virology , Male , Re-Epithelialization , SARS-CoV-2/pathogenicity , Vero Cells , Viral Load
9.
J Clin Invest ; 131(14)2021 07 15.
Article in English | MEDLINE | ID: covidwho-1311202

ABSTRACT

BACKGROUNDWeeks after SARS-CoV-2 infection or exposure, some children develop a severe, life-threatening illness called multisystem inflammatory syndrome in children (MIS-C). Gastrointestinal (GI) symptoms are common in patients with MIS-C, and a severe hyperinflammatory response ensues with potential for cardiac complications. The cause of MIS-C has not been identified to date.METHODSHere, we analyzed biospecimens from 100 children: 19 with MIS-C, 26 with acute COVID-19, and 55 controls. Stools were assessed for SARS-CoV-2 by reverse transcription PCR (RT-PCR), and plasma was examined for markers of breakdown of mucosal barrier integrity, including zonulin. Ultrasensitive antigen detection was used to probe for SARS-CoV-2 antigenemia in plasma, and immune responses were characterized. As a proof of concept, we treated a patient with MIS-C with larazotide, a zonulin antagonist, and monitored the effect on antigenemia and the patient's clinical response.RESULTSWe showed that in children with MIS-C, a prolonged presence of SARS-CoV-2 in the GI tract led to the release of zonulin, a biomarker of intestinal permeability, with subsequent trafficking of SARS-CoV-2 antigens into the bloodstream, leading to hyperinflammation. The patient with MIS-C treated with larazotide had a coinciding decrease in plasma SARS-CoV-2 spike antigen levels and inflammatory markers and a resultant clinical improvement above that achieved with currently available treatments.CONCLUSIONThese mechanistic data on MIS-C pathogenesis provide insight into targets for diagnosing, treating, and preventing MIS-C, which are urgently needed for this increasingly common severe COVID-19-related disease in children.


Subject(s)
COVID-19/etiology , COVID-19/physiopathology , Haptoglobins/physiology , Intestinal Mucosa/physiopathology , Protein Precursors/physiology , SARS-CoV-2 , Systemic Inflammatory Response Syndrome/etiology , Systemic Inflammatory Response Syndrome/physiopathology , Adolescent , Antigens, Viral/blood , Biomarkers/blood , COVID-19/virology , Case-Control Studies , Child , Child, Preschool , Female , Haptoglobins/antagonists & inhibitors , Humans , Infant , Infant, Newborn , Intestinal Mucosa/drug effects , Intestinal Mucosa/virology , Male , Oligopeptides/pharmacology , Permeability/drug effects , Proof of Concept Study , Protein Precursors/antagonists & inhibitors , Protein Precursors/blood , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/blood , Spike Glycoprotein, Coronavirus/immunology , Systemic Inflammatory Response Syndrome/virology , Young Adult
10.
J Virol ; 95(18): e0085321, 2021 08 25.
Article in English | MEDLINE | ID: covidwho-1299218

ABSTRACT

Porcine epidemic diarrhea virus (PEDV) is an enteric coronavirus causing acute intestinal infection in pigs, with high mortality often seen in neonatal pigs. The newborns rely on innate immune responses against invading pathogens because of lacking adaptive immunity. However, how PEDV disables the innate immunity of newborns toward severe infection remains unknown. We found that PEDV infection led to reduced expression of histone deacetylases (HDACs), especially HDAC1, in porcine IPEC-J2 cells. HDACs are considered important regulators of innate immunity. We hypothesized that PEDV interacts with certain host factors to regulate HDAC1 expression in favor of its replication. We show that HDAC1 acted as a negative regulator of PEDV replication in IPEC-J2 cells, as shown by chemical inhibition, gene knockout, and overexpression. A GC-box (GCCCCACCCCC) within the HDAC1 promoter region was identified for Sp1 binding in IPEC-J2 cells. Treatment of the cells with Sp1 inhibitor mithramycin A inhibited HDAC1 expression, indicating direct regulation of HDAC1 expression by Sp1. Of the viral proteins that were overexpressed in IPEC-J2 cells, the N protein was found to be present in the nuclei and more inhibitory to HDAC1 transcription. The putative nuclear localization sequence 261PKKNKSR267 contributed to its nuclear localization. The N protein interacted with Sp1 and interfered with its binding to the promoter region, thereby inhibiting its transcriptional activity for HDAC1 expression. Our findings reveal a novel mechanism of PEDV evasion of the host responses, offering implications for studying the infection processes of other coronaviruses. IMPORTANCE The enteric coronavirus porcine epidemic diarrhea virus (PEDV) causes fatal acute intestinal infection in neonatal pigs that rely on innate immune responses. Histone deacetylases (HDACs) play important roles in innate immune regulation. Our study found PEDV suppresses HDAC1 expression via the interaction of its N protein and porcine Sp1, which identified a novel mechanism of PEDV evasion of the host responses to benefit its replication. This study suggests that other coronaviruses, including SARS-CoV and SARS-CoV-2, also make use of their N proteins to intercept the host immune responses in favor of their infection.


Subject(s)
Coronavirus Infections/veterinary , Epithelial Cells/virology , Histone Deacetylase 1/antagonists & inhibitors , Intestinal Mucosa/virology , Sp1 Transcription Factor/metabolism , Swine Diseases/virology , Viral Nonstructural Proteins/metabolism , Virus Replication , Animals , Cells, Cultured , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Epithelial Cells/metabolism , Epithelial Cells/pathology , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Porcine epidemic diarrhea virus/pathogenicity , Sp1 Transcription Factor/genetics , Swine , Swine Diseases/metabolism , Swine Diseases/pathology , Viral Nonstructural Proteins/genetics
11.
Clin Transl Gastroenterol ; 12(6): e00348, 2021 06 04.
Article in English | MEDLINE | ID: covidwho-1259760

ABSTRACT

INTRODUCTION: Patients with community-acquired pneumonia display enhanced levels of lipopolysaccharides (LPS) compared with controls, suggesting that low-grade endotoxemia may be implicated in vascular disturbances. It is unknown whether this occurs in patients with coronavirus 2019 (COVID-19) and its impact on thrombotic complications. METHODS: We measured serum levels of zonulin, a marker of gut permeability, LPS, and D-dimer in 81 patients with COVID-19 and 81 healthy subjects; the occurrence of thrombotic events in COVID-19 during the intrahospital stay was registered. RESULTS: Serum LPS and zonulin were higher in patients with COVID-19 than in control subjects and, in COVID-19, significantly correlated (R = 0.513; P < 0.001). Among the 81 patients with COVID-19, 11 (14%) experienced thrombotic events in the arterial (n = 5) and venous circulation (n = 6) during a median follow-up of 18 days (interquartile range 11-27 days). A logistic regression analysis showed that LPS (P = 0.024) and D-dimer (P = 0.041) independently predicted thrombotic events. DISCUSSION: The study reports that low-grade endotoxemia is detectable in patients with COVID-19 and is associated with thrombotic events. The coexistence of low-grade endotoxemia with enhanced levels of zonulin may suggest enhanced gut permeability as an underlying mechanism.


Subject(s)
COVID-19 , Endotoxemia , Haptoglobins/metabolism , Intestinal Mucosa , Protein Precursors/metabolism , SARS-CoV-2 , Thrombosis , Biomarkers/blood , COVID-19/blood , COVID-19/complications , COVID-19/physiopathology , Correlation of Data , Endotoxemia/diagnosis , Endotoxemia/metabolism , Endotoxemia/virology , Female , Fibrin Fibrinogen Degradation Products/analysis , Humans , Intestinal Mucosa/metabolism , Intestinal Mucosa/virology , Lipopolysaccharides/analysis , Male , Middle Aged , Permeability , Pneumonia, Viral/diagnosis , Pneumonia, Viral/etiology , SARS-CoV-2/pathogenicity , SARS-CoV-2/physiology , Thrombosis/blood , Thrombosis/diagnosis , Thrombosis/etiology
12.
Curr Opin Virol ; 49: 21-26, 2021 08.
Article in English | MEDLINE | ID: covidwho-1198681

ABSTRACT

Impacts of respiratory tract viruses have long been appreciated to highly heterogeneous both between and within various populations. The SARS-CoV-2 pandemic, which is the first time that a pathogen's spread across the globe has been extensively monitored by direct detection of the pathogen itself rather just than the morbidity left in its wake, indicates such heterogeneity is not limited to outcomes of infections but whether infection of a particular host occurs at all. This suggests an important role for yet to be discovered environmental (i.e. non-genetic) factors that influence whether an exposure to the virus initiates a productive infection and, moreover, the severity of disease that results. This article discusses the emerging hypothesis that the composition of a host's commensal microbial communities, that is, its 'microbiome', may be one such determinant that influences outcomes following encounters with respiratory viral pathogens in general and SARS-CoV-2 in particular. Specifically, we will review the rationales and evidence that supports this hypothesis and, moreover, speculate as to possible approaches to manipulate microbiota to ameliorate disease induced by respiratory viral pathogens.


Subject(s)
COVID-19/microbiology , COVID-19/therapy , Microbiota/physiology , Adaptive Immunity , COVID-19/epidemiology , COVID-19/immunology , Gastrointestinal Microbiome , Host-Pathogen Interactions , Humans , Intestinal Mucosa/immunology , Intestinal Mucosa/microbiology , Intestinal Mucosa/virology , Microbial Interactions , Respiratory Tract Infections/immunology , Respiratory Tract Infections/microbiology , Respiratory Tract Infections/virology , SARS-CoV-2
13.
Stem Cell Reports ; 16(4): 940-953, 2021 04 13.
Article in English | MEDLINE | ID: covidwho-1180038

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leading to coronavirus disease 2019 (COVID-19) usually results in respiratory disease, but extrapulmonary manifestations are of major clinical interest. Intestinal symptoms of COVID-19 are present in a significant number of patients, and include nausea, diarrhea, and viral RNA shedding in feces. Human induced pluripotent stem cell-derived intestinal organoids (HIOs) represent an inexhaustible cellular resource that could serve as a valuable tool to study SARS-CoV-2 as well as other enteric viruses that infect the intestinal epithelium. Here, we report that SARS-CoV-2 productively infects both proximally and distally patterned HIOs, leading to the release of infectious viral particles while stimulating a robust transcriptomic response, including a significant upregulation of interferon-related genes that appeared to be conserved across multiple epithelial cell types. These findings illuminate a potential inflammatory epithelial-specific signature that may contribute to both the multisystemic nature of COVID-19 as well as its highly variable clinical presentation.


Subject(s)
COVID-19/pathology , Colon/pathology , Intestinal Mucosa/pathology , Organoids/pathology , Cell Line , Colon/virology , Epithelial Cells/virology , Humans , Induced Pluripotent Stem Cells/cytology , Inflammation/virology , Intestinal Mucosa/virology , Models, Biological , Organoids/cytology , Organoids/virology , SARS-CoV-2 , Virus Replication/physiology
14.
Gastroenterology ; 160(7): 2435-2450.e34, 2021 06.
Article in English | MEDLINE | ID: covidwho-1116737

ABSTRACT

BACKGROUND & AIMS: Given that gastrointestinal (GI) symptoms are a prominent extrapulmonary manifestation of COVID-19, we investigated intestinal infection with SARS-CoV-2, its effect on pathogenesis, and clinical significance. METHODS: Human intestinal biopsy tissues were obtained from patients with COVID-19 (n = 19) and uninfected control individuals (n = 10) for microscopic examination, cytometry by time of flight analyses, and RNA sequencing. Additionally, disease severity and mortality were examined in patients with and without GI symptoms in 2 large, independent cohorts of hospitalized patients in the United States (N = 634) and Europe (N = 287) using multivariate logistic regressions. RESULTS: COVID-19 case patients and control individuals in the biopsy cohort were comparable for age, sex, rates of hospitalization, and relevant comorbid conditions. SARS-CoV-2 was detected in small intestinal epithelial cells by immunofluorescence staining or electron microscopy in 15 of 17 patients studied. High-dimensional analyses of GI tissues showed low levels of inflammation, including down-regulation of key inflammatory genes including IFNG, CXCL8, CXCL2, and IL1B and reduced frequencies of proinflammatory dendritic cells compared with control individuals. Consistent with these findings, we found a significant reduction in disease severity and mortality in patients presenting with GI symptoms that was independent of sex, age, and comorbid illnesses and despite similar nasopharyngeal SARS-CoV-2 viral loads. Furthermore, there was reduced levels of key inflammatory proteins in circulation in patients with GI symptoms. CONCLUSIONS: These data highlight the absence of a proinflammatory response in the GI tract despite detection of SARS-CoV-2. In parallel, reduced mortality in patients with COVID-19 presenting with GI symptoms was observed. A potential role of the GI tract in attenuating SARS-CoV-2-associated inflammation needs to be further examined.


Subject(s)
COVID-19/virology , Gastrointestinal Diseases/virology , Immunity, Mucosal , Intestinal Mucosa/virology , SARS-CoV-2/pathogenicity , Aged , Aged, 80 and over , COVID-19/diagnosis , COVID-19/immunology , COVID-19/mortality , Case-Control Studies , Cells, Cultured , Cytokines/blood , Female , Gastrointestinal Diseases/diagnosis , Gastrointestinal Diseases/immunology , Gastrointestinal Diseases/mortality , Host-Pathogen Interactions , Humans , Inflammation Mediators/blood , Intestinal Mucosa/immunology , Italy , Male , Middle Aged , New York City , Prognosis , Risk Assessment , Risk Factors , SARS-CoV-2/immunology , Viral Load
15.
Stem Cell Reports ; 16(3): 493-504, 2021 03 09.
Article in English | MEDLINE | ID: covidwho-1099264

ABSTRACT

Enteroviruses, such as EV-A71 and CVA16, mainly infect the human gastrointestinal tract. Human coronaviruses, including SARS-CoV and SARS-CoV-2, have been variably associated with gastrointestinal symptoms. We aimed to optimize the human intestinal organoids and hypothesize that these optimized intestinal organoids can recapitulate enteric infections of enterovirus and coronavirus. We demonstrate that the optimized human intestinal organoids enable better simulation of the native human intestinal epithelium, and that they are significantly more susceptible to EV-A71 than CVA16. Higher replication of EV-A71 than CVA16 in the intestinal organoids triggers a more vigorous cellular response. However, SARS-CoV and SARS-CoV-2 exhibit distinct dynamics of virus-host interaction; more robust propagation of SARS-CoV triggers minimal cellular response, whereas, SARS-CoV-2 exhibits lower replication capacity but elicits a moderate cellular response. Taken together, the disparate profile of the virus-host interaction of enteroviruses and coronaviruses in human intestinal organoids may unravel the cellular basis of the distinct pathogenicity of these viral pathogens.


Subject(s)
COVID-19/virology , Enterovirus A, Human/pathogenicity , Enterovirus Infections/virology , Intestines/virology , Organoids/virology , SARS-CoV-2/pathogenicity , Animals , Cell Line , Chlorocebus aethiops , Host Microbial Interactions/physiology , Humans , Intestinal Mucosa/virology , Vero Cells , Virus Replication/physiology
16.
Gut Microbes ; 13(1): 1-9, 2021.
Article in English | MEDLINE | ID: covidwho-1069185

ABSTRACT

Microbiota-derived molecules called short-chain fatty acids (SCFAs) play a key role in the maintenance of the intestinal barrier and regulation of immune response during infectious conditions. Recent reports indicate that SARS-CoV-2 infection changes microbiota and SCFAs production. However, the relevance of this effect is unknown. In this study, we used human intestinal biopsies and intestinal epithelial cells to investigate the impact of SCFAs in the infection by SARS-CoV-2. SCFAs did not change the entry or replication of SARS-CoV-2 in intestinal cells. These metabolites had no effect on intestinal cells' permeability and presented only minor effects on the production of anti-viral and inflammatory mediators. Together our findings indicate that the changes in microbiota composition of patients with COVID-19 and, particularly, of SCFAs do not interfere with the SARS-CoV-2 infection in the intestine.


Subject(s)
COVID-19/virology , Fatty Acids, Volatile/metabolism , Gastrointestinal Microbiome , Intestinal Mucosa/virology , Adult , Aged , Caco-2 Cells , Colon/virology , Epithelial Cells/virology , Female , Humans , In Vitro Techniques , Male , Middle Aged , SARS-CoV-2/pathogenicity , SARS-CoV-2/physiology , Viral Load , Virus Internalization , Young Adult
17.
EMBO Mol Med ; 13(4): e13191, 2021 04 09.
Article in English | MEDLINE | ID: covidwho-1068062

ABSTRACT

SARS-CoV-2, the agent that causes COVID-19, invades epithelial cells, including those of the respiratory and gastrointestinal mucosa, using angiotensin-converting enzyme-2 (ACE2) as a receptor. Subsequent inflammation can promote rapid virus clearance, but severe cases of COVID-19 are characterized by an inefficient immune response that fails to clear the infection. Using primary epithelial organoids from human colon, we explored how the central antiviral mediator IFN-γ, which is elevated in COVID-19, affects epithelial cell differentiation, ACE2 expression, and susceptibility to infection with SARS-CoV-2. In mouse and human colon, ACE2 is mainly expressed by surface enterocytes. Inducing enterocyte differentiation in organoid culture resulted in increased ACE2 production. IFN-γ treatment promoted differentiation into mature KRT20+ enterocytes expressing high levels of ACE2, increased susceptibility to SARS-CoV-2 infection, and resulted in enhanced virus production in infected cells. Similarly, infection-induced epithelial interferon signaling promoted enterocyte maturation and enhanced ACE2 expression. We here reveal a mechanism by which IFN-γ-driven inflammatory responses induce a vulnerable epithelial state with robust replication of SARS-CoV-2, which may have an impact on disease outcome and virus transmission.


Subject(s)
COVID-19/etiology , Interferon-gamma/immunology , Models, Immunological , SARS-CoV-2 , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/immunology , COVID-19/pathology , Cell Differentiation/immunology , Colon/immunology , Colon/pathology , Colon/virology , Disease Susceptibility , Enterocytes/metabolism , Enterocytes/pathology , Enterocytes/virology , Gene Expression , Host Microbial Interactions/immunology , Humans , Interferon-gamma/administration & dosage , Intestinal Mucosa/immunology , Intestinal Mucosa/pathology , Intestinal Mucosa/virology , Mice , Organoids/immunology , Organoids/pathology , Organoids/virology , SARS-CoV-2/genetics , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Virus Replication/immunology
18.
Virology ; 556: 1-8, 2021 04.
Article in English | MEDLINE | ID: covidwho-1045103

ABSTRACT

Porcine deltacoronavirus (PDCoV) is one of the emerged coronaviruses posing a significant threat to the swine industry. Previous work showed the presence of a viral accessory protein NS6 in PDCoV-infected cells. In this study, we detected the expression of the NS6 protein in small intestinal tissues of PDCoV-infected piglets. In addition, SDS-PAGE and Western blot analysis of sucrose gradient-purified virions showed the presence of a 13-kDa NS6 protein. Further evidences of the presence of NS6 in the PDCoV virions were obtained by immunogold staining of purified virions with anti-NS6 antiserum, and by immunoprecipitation of NS6 from purified virions. Finally, the anti-NS6 antibody was not able to neutralize PDCoV in cultured cells. These data establish for the first time that the accessory protein NS6 is expressed during infection in vivo and incorporated into PDCoV virions.


Subject(s)
Coronavirus Infections/veterinary , Deltacoronavirus/metabolism , Swine Diseases/virology , Viral Nonstructural Proteins/metabolism , Virion/metabolism , Animals , Antibodies, Viral/immunology , Cell Line , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Intestinal Mucosa/metabolism , Intestinal Mucosa/virology , Mice , Rabbits , Swine , Swine Diseases/metabolism , Viral Nonstructural Proteins/immunology
19.
mBio ; 12(1)2021 01 12.
Article in English | MEDLINE | ID: covidwho-1029053

ABSTRACT

Coronavirus disease 2019 (COVID-19), which has been declared a pandemic, has exhibited a wide range of severity worldwide. Although this global variation is largely affected by socio-medical situations in each country, there is also high individual-level variation attributable to elderliness and certain underlying medical conditions, including high blood pressure, diabetes, and obesity. As both elderliness and the aforementioned chronic conditions are often associated with an altered gut microbiota, resulting in disrupted gut barrier integrity, and gut symptoms have consistently been associated with more severe illness in COVID-19 patients, it is possible that dysfunction of the gut as a whole influences COVID-19 severity. This article summarizes the accumulating evidence that supports the hypothesis that an altered gut microbiota and its associated leaky gut may contribute to the onset of gastrointestinal symptoms and occasionally to additional multiorgan complications that may lead to severe illness by allowing leakage of the causative coronavirus into the circulatory system.


Subject(s)
COVID-19/pathology , Gastrointestinal Diseases/pathology , Gastrointestinal Microbiome , SARS-CoV-2/pathogenicity , COVID-19/complications , COVID-19/virology , Dysbiosis , Gastrointestinal Diseases/complications , Gastrointestinal Diseases/virology , Humans , Intestinal Mucosa/pathology , Intestinal Mucosa/virology , Severity of Illness Index
20.
Aging (Albany NY) ; 12(22): 22425-22444, 2020 11 22.
Article in English | MEDLINE | ID: covidwho-969889

ABSTRACT

With the current COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is an urgent need for new therapies and prevention strategies that can help curtail disease spread and reduce mortality. The inhibition of viral entry and thus spread is a plausible therapeutic avenue. SARS-CoV-2 uses receptor-mediated entry into a human host via the angiotensin-converting enzyme 2 (ACE2), which is expressed in lung tissue as well as the oral and nasal mucosa, kidney, testes and gastrointestinal tract. The modulation of ACE2 levels in these gateway tissues may be an effective strategy for decreasing disease susceptibility. Cannabis sativa, especially those high in the anti-inflammatory cannabinoid cannabidiol (CBD), has been found to alter gene expression and inflammation and harbour anti-cancer and anti-inflammatory properties. However, its effects on ACE2 expression remain unknown. Working under a Health Canada research license, we developed over 800 new C. sativa cultivars and hypothesized that high-CBD C. sativa extracts may be used to down-regulate ACE2 expression in target COVID-19 tissues. Using artificial 3D human models of oral, airway and intestinal tissues, we identified 13 high-CBD C. sativa extracts that decrease ACE2 protein levels. Some C. sativa extracts down-regulate serine protease TMPRSS2, another critical protein required for SARS-CoV-2 entry into host cells. While our most effective extracts require further large-scale validation, our study is important for future analyses of the effects of medical cannabis on COVID-19. The extracts of our most successful novel high-CBD C. sativa lines, pending further investigation, may become a useful and safe addition to the prevention/treatment of COVID-19 as an adjunct therapy.


Subject(s)
Angiotensin-Converting Enzyme 2/antagonists & inhibitors , COVID-19/prevention & control , Cannabis/chemistry , Plant Extracts/pharmacology , SARS-CoV-2/drug effects , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/drug therapy , COVID-19/epidemiology , COVID-19/virology , Cannabidiol/pharmacology , Cannabidiol/therapeutic use , Computer Simulation , Gene Expression Regulation/drug effects , Humans , Intestinal Mucosa/drug effects , Intestinal Mucosa/metabolism , Intestinal Mucosa/virology , Models, Anatomic , Mouth Mucosa/drug effects , Mouth Mucosa/metabolism , Mouth Mucosa/virology , Pandemics/prevention & control , Plant Extracts/chemistry , Plant Extracts/therapeutic use , Respiratory Mucosa/drug effects , Respiratory Mucosa/metabolism , Respiratory Mucosa/virology , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Virus Internalization/drug effects
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