The coronavirus disease 2019 (COVID-19) pandemic is caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is spread primary via respiratory droplets and infects the lungs. Currently widely used cell lines and animals are unable to accurately mimic human physiological conditions because of the abnormal status of cell lines (transformed or cancer cells) and species differences between animals and humans. Organoids are stem cell-derived self-organized three-dimensional culture in vitro and model the physiological conditions of natural organs. Here we showed that SARS-CoV-2 infected and extensively replicated in human embryonic stem cells (hESCs)-derived lung organoids, including airway and alveolar organoids which covered the complete infection and spread route for SARS-CoV-2 within lungs. The infected cells were ciliated, club, and alveolar type 2 (AT2) cells, which were sequentially located from the proximal to the distal airway and terminal alveoli, respectively. Additionally, RNA-seq revealed early cell response to virus infection including an unexpected downregulation of the metabolic processes, especially lipid metabolism, in addition to the well-known upregulation of immune response. Further, Remdesivir and a human neutralizing antibody potently inhibited SARS-CoV-2 replication in lung organoids. Therefore, human lung organoids can serve as a pathophysiological model to investigate the underlying mechanism of SARS-CoV-2 infection and to discover and test therapeutic drugs for COVID-19.
Adenosine Monophosphate/therapeutic use* ; Alanine/therapeutic use* ; Alveolar Epithelial Cells/virology* ; Antibodies, Neutralizing/therapeutic use* ; COVID-19/virology* ; Down-Regulation ; Drug Discovery ; Human Embryonic Stem Cells/metabolism* ; Humans ; Immunity ; Lipid Metabolism ; Lung/virology* ; RNA, Viral/metabolism* ; SARS-CoV-2/physiology* ; Virus Replication/drug effects*

Betacoronavirus ; isolation & purification ; pathogenicity ; Bile Acids and Salts ; metabolism ; Bile Ducts, Intrahepatic ; pathology ; virology ; Cell Culture Techniques ; Coronavirus Infections ; complications ; pathology ; Cytokine Release Syndrome ; etiology ; physiopathology ; Cytopathogenic Effect, Viral ; Epithelial Cells ; enzymology ; pathology ; virology ; Humans ; Hyperbilirubinemia ; etiology ; Liver ; pathology ; Organoids ; pathology ; virology ; Pandemics ; Peptidyl-Dipeptidase A ; analysis ; Pneumonia, Viral ; complications ; pathology ; Receptors, Virus ; analysis ; Serine Endopeptidases ; analysis ; Viral Load

OBJECTIVE: Newly identified human rhinovirus C (HRV-C) and human bocavirus (HBoV) cannot propagate in vitro in traditional cell culture models; thus obtaining knowledge about these viruses and developing related vaccines are difficult. Therefore, it is necessary to develop a novel platform for the propagation of these types of viruses. METHODS: A platform for culturing human airway epithelia in a three-dimensional (3D) pattern using Matrigel as scaffold was developed. The features of 3D culture were identified by immunochemical staining and transmission electron microscopy. Nucleic acid levels of HRV-C and HBoV in 3D cells at designated time points were quantitated by real-time polymerase chain reaction (PCR). Levels of cytokines, whose secretion was induced by the viruses, were measured by ELISA. RESULTS: Properties of bronchial-like tissues, such as the expression of biomarkers CK5, ZO-1, and PCK, and the development of cilium-like protuberances indicative of the human respiration tract, were observed in 3D-cultured human airway epithelial (HAE) cultures, but not in monolayer-cultured cells. Nucleic acid levels of HRV-C and HBoV and levels of virus-induced cytokines were also measured using the 3D culture system. CONCLUSION Our data provide a preliminary indication that the 3D culture model of primary epithelia using a Matrigel scaffold in vitro can be used to propagate HRV-C and HBoV.
Collagen ; Drug Combinations ; Enterovirus ; growth & development ; isolation & purification ; Enterovirus Infections ; virology ; Enzyme-Linked Immunosorbent Assay ; Epithelial Cells ; virology ; Human bocavirus ; growth & development ; isolation & purification ; Humans ; Laminin ; Parvoviridae Infections ; virology ; Primary Cell Culture ; methods ; Proteoglycans ; Real-Time Polymerase Chain Reaction ; Respiratory Mucosa ; virology ; Virus Cultivation

OBJECTIVETo investigate the expression of IFN-λ1 in respiratory epithelial cells of children with respiratory syncytial virus (RSV) infection and its relationship with RSV load.

METHODSThe nasopharyngeal swabs were collected from the children who were hospitalized with respiratory tract infection from June 2015 to June 2016. A direct immunofluorescence assay was used to detect the antigens of seven common respiratory viruses (including RSV) in the nasopharyngeal swabs. A total of 120 children who were only RSV positive were selected as the RSV infection group. A total of 50 children who had negative results in the detection of all viral antigens were selected as the healthy control group. Fluorescence quantitative real-time PCR was used to determine the RSV load and the expression of IFN-λ1 mRNA in the nasopharyngeal swabs of children in the two groups.

RESULTSThe expression of IFN-λ1 in the RSV infection group was significantly higher than that in the healthy control group (P<0.05). The expression of IFN-λ1 was positively correlated with RSV load (r=0.56, P<0.05).

CONCLUSIONSRSV can induce the expression of IFN-λ1 in respiratory epithelial cells, suggesting that IFN-λ1 may play an important role in anti-RSV infection.

Antigens, Viral ; analysis ; Child, Preschool ; Epithelial Cells ; immunology ; Female ; Humans ; Infant ; Infant, Newborn ; Interleukins ; analysis ; physiology ; Male ; Nasopharynx ; microbiology ; Real-Time Polymerase Chain Reaction ; Respiratory Syncytial Virus Infections ; immunology ; virology ; Viral Load

OBJECTIVE: To explore the mechanisms for an increase in susceptibility of asthma induced by respiratory syncytial virus (RSV), to observe the expression of interleukin-8 (IL-8) in human bronchial epithelial cells (HBECs) after RSV infection and to invesigate the regulatory effect of IL-8 on Th17/Treg differentiation.
 METHODS: HBECs were divided into a control group and a RSV infected group. The RSVE-infected model of HBECs was established and examined. The expression of IL-8 mRNA was detected by real-time PCR, and the levels of IL-8 were measured by ELISA. Peripheral blood lymphocytes in healthy people were extracted and divided into a control group and an IL-8 treatment group. Based on concentration of IL-8 in RSV-infected HBECs, lymphocytes were treated by a matched concentration of human recombinant IL-8 for 24 h. The distribution of Th17 and Treg subsets in lymphocytes were examined by flow cytometry.
 RESULTS: The RSV-infected HBECs model was successfully established. The infected HBECs were still able to split and passage. The RSV could be detected in every passage in the infected cells. Virus particles indicated by bright yellow green fluorescence were seen under fluorescence microscope. Edema of mitochondrias, expansion of endoplasmic reticulum, fissure around nucleus and intracellular virus particles were all observed under electron microscope. The expression IL-8 mRNA were significantly enhanced in the RSV-infected group, and the level of IL-8 in the RSV-infected group was higher than that in the control group (P<0.05). After IL-8 treatment for 24 h, the ratio of Th17 subsets in lymphocytes were dramatically increased compared to the control group (P<0.05), but there was no difference in the ratio of Treg subsets between the 2 groups (P>0.05).
 CONCLUSION Over-secretion of IL-8 by the RSV-infected HBECs may promote the differentiation of Th17 subsets and maintain the Th17/Tred imbalance.
Cell Differentiation ; Cells, Cultured ; Epithelial Cells ; drug effects ; virology ; Flow Cytometry ; Humans ; Interleukin-8 ; immunology ; pharmacology ; Real-Time Polymerase Chain Reaction ; Recombinant Proteins ; pharmacology ; Respiratory Syncytial Virus Infections ; immunology ; Respiratory Syncytial Viruses ; T-Lymphocytes, Regulatory ; cytology ; Th17 Cells ; cytology

For rapid and accurate screening of recombinant modified vaccinia virus Ankara (rMVA) that satisfied the quality standards of clinical trials, a novel shuttle vector that can delete the marker gene automatically during virus propagation was construted: pZL-EGFP. To construct the pZL-EGFP, the original shuttle vector pSC11 was modified by replacing the LacZ marker gene with enhanced green fluorescent protein (EGFP) and then inserting homologous sequences of TKL into the flank regions of EGFP. Baby hamster kidney (BHK)-21 cells were cotransfected with pZL-EGFP and MVA, and underwent ten passages and one plaque screening to obtain the EGFP-free rMVA carrying the exogenous gene. Resulting rMVA was tested by polymerase chain reaction and western blotting to verify pZL-EGFP function. A novel shuttle vector pZL-EGFP containing an EGFP marker gene which could be deleted automatically was constructed. This gene deletion had no effect on the activities of rMVA, and the exogenous gene could be expressed stably. These results suggest that rMVA can be packaged efficiently by homologous recombination between pZL-EGFP and MVA in BHK-21 cells, and that the carried EGFP gene can be removed automatically by intramolecular homologous recombination during virus passage. Meanwhile, the gene deletion had no influence on the activities of rMVA and the expression of exogenous target gene. This study lays a solid foundation for the future research.
Animals ; Biomarkers ; Cricetinae ; Epithelial Cells ; virology ; Gene Deletion ; Genetic Engineering ; methods ; Genetic Vectors ; genetics ; metabolism ; Green Fluorescent Proteins ; genetics ; metabolism ; Humans ; Recombination, Genetic ; Vaccinia ; virology ; Vaccinia virus ; genetics ; physiology ; Virus Replication

Respiratory virus poses a serious threat to human life and health. Airway epithelial cells are the body's first line of defense from a wide variety of foreign pathogens, such as viruses and bacteria. Therefore, successful airway epithelial cell culture can provide a model for investigating the mechanisms underlying respiratory pathogenic diseases following airway virus infection. This respiratory disease model can also be used for the potential development of novel therapeutics. Here we provide a brief review of recent developments on the culture of cells derived from human trachea-bronchial airway epithelium, and the application of this model for studying respiratory virus and disease.
Animals ; Cell Culture Techniques ; Epithelial Cells ; virology ; Humans ; Respiratory Tract Diseases ; virology ; Virus Diseases ; virology ; Virus Physiological Phenomena ; Viruses ; genetics ; isolation & purification

Epstein-Barr virus (EBV) is a human herpesvirus associated with important human diseases, including infectious mononucleosis syndrome, malignant lymphoma, and nasopharyngeal carcinoma. The mechanism of EBV entry into host cells remains a subject of intensive research. After decades of study, researchers have identified several key proteins and different patterns of EBV intrusion into host cells. The viral surface glycoproteins, gp350/220, gp42, gB, gH, and gL, are involved in interactions with the CR2 receptor on the surface of B lymphocytes during viral entry. However, the majority of epithelial cells lack CR2 receptor expression, which makes viral invasion much more complex than in B lymphocytes. Three different models have been proposed to explain how EBV enters epithelial cells: (1) "transfer of infection", mediated by B lymphocytes or Langerhans cells; (2) EBV utilizes its own proteins during the process of fusion with the cell membrane; and (3) progeny virions arising from EBV-infected epithelial cells cross lateral membranes into adjacent epithelial cells. This review will discuss the relevant mechanism of viral entry into B lymphocytes and epithelial cells during EBV infection.
Animals ; B-Lymphocytes ; virology ; Epithelial Cells ; virology ; Epstein-Barr Virus Infections ; virology ; Herpesvirus 4, Human ; genetics ; physiology ; Humans ; Viral Proteins ; genetics ; metabolism ; Virus Internalization

We report the case of a patient who presented with cystic lymphoid hyperplasia of the right parotid gland as the index diagnosis of HIV infection. Histological examination of the excised parotid gland revealed a solid-cystic lymphoepithelial lesion with a non-keratinous squamous epithelium, which grew into the lymphoid component via anastomosing cords and islands. These anastomosing cords and islands contained variably abundant B cells, several subepithelial multinucleated histiocytes, salivary ducts infiltrated by small lymphocytes, and a dense lymphoid infiltrate containing lymphoid follicles with enlarged, irregular germinal centres.
Adult ; B-Lymphocytes ; cytology ; Biopsy ; Epithelial Cells ; cytology ; Epithelium ; metabolism ; HIV Infections ; diagnosis ; Humans ; Hyperplasia ; pathology ; virology ; Immunohistochemistry ; Lymphocytes ; cytology ; Male ; Parotid Gland ; pathology ; virology ; Salivary Glands ; pathology ; Tomography, X-Ray Computed

Since its discovery 50 years ago, Epstein-Barr virus (EBV) has been linked to the development of cancers originating from both lymphoid and epithelial cells. Approximately 95% of the world's population sustains an asymptomatic, life-long infection with EBV. The virus persists in the memory B-cell pool of normal healthy individuals, and any disruption of this interaction results in virus-associated B-cell tumors. The association of EBV with epithelial cell tumors, specifically nasopharyngeal carcinoma (NPC) and EBV-positive gastric carcinoma (EBV-GC), is less clear and is currently thought to be caused by the aberrant establishment of virus latency in epithelial cells that display premalignant genetic changes. Although the precise role of EBV in the carcinogenic process is currently poorly understood, the presence of the virus in all tumor cells provides opportunities for developing novel therapeutic and diagnostic approaches. The study of EBV and its role in carcinomas continues to provide insight into the carcinogenic process that is relevant to a broader understanding of tumor pathogenesis and to the development of targeted cancer therapies.
B-Lymphocytes ; Carcinoma ; Epithelial Cells ; Epstein-Barr Virus Infections ; complications ; Herpesvirus 4, Human ; Humans ; Lymphoma, B-Cell ; Nasopharyngeal Neoplasms ; virology ; Stomach Neoplasms