scholarly journals The Coronavirus Transmissible Gastroenteritis Virus Causes Infection after Receptor-Mediated Endocytosis and Acid-Dependent Fusion with an Intracellular Compartment

1998 ◽  
Vol 72 (1) ◽  
pp. 527-534 ◽  
Author(s):  
G. H. Hansen ◽  
B. Delmas ◽  
L. Besnardeau ◽  
L. K. Vogel ◽  
H. Laude ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Mdck Cells ◽  
Protein Biosynthesis ◽  
Aminopeptidase N ◽  
Productive Infection ◽  
Transmissible Gastroenteritis Virus ◽  
Intracellular Compartment ◽  
Gastroenteritis Virus ◽  
Apical Vesicles ◽  
Transmissible Gastroenteritis

ABSTRACT Aminopeptidase N is a species-specific receptor for transmissible gastroenteritis virus (TGEV), which infects piglets, and for the 229E virus, which infects humans. It is not known whether these coronaviruses are endocytosed before fusion with a membrane of the target cell, causing a productive infection, or whether they fuse directly with the plasma membrane. We have studied the interaction between TGEV and a cell line (MDCK) stably expressing recombinant pig aminopeptidase N (pAPN). By electron microscopy and flow cytometry, TGEV was found to be associated with the plasma membrane after adsorption to the pAPN-MDCK cells. TGEV was also observed in endocytic pits and apical vesicles after 3 to 10 min of incubation at 38°C. The number of pits and apical vesicles was increased by the TGEV incubation, indicating an increase in endocytosis. After 10 min of incubation, a distinct TGEV-pAPN-containing population of large intracellular vesicles, morphologically compatible with endosomes, was found. A higher density of pAPN receptors was observed in the pits beneath the virus particles than in the surrounding plasma membrane, indicating that TGEV recruits pAPN receptors before endocytosis. Ammonium chloride and bafilomycin A1 markedly inhibited the TGEV infection as judged from virus production and protein biosynthesis analyses but did so only when added early in the course of the infection, i.e., about 1 h after the start of endocytosis. Together our results point to an acid intracellular compartment as the site of fusion for TGEV.

scholarly journals Porcine Deltacoronavirus Engages the Transmissible Gastroenteritis Virus Functional Receptor Porcine Aminopeptidase N for Infectious Cellular Entry

2018 ◽  
Vol 92 (12) ◽  
Author(s):  
Bin Wang ◽  
Yan Liu ◽  
Chun-Miao Ji ◽  
Yong-Le Yang ◽  
Qi-Zhang Liang ◽  
...  
Keyword(s):  
Intervention Strategies ◽  
Aminopeptidase N ◽  
Productive Infection ◽  
Transmissible Gastroenteritis Virus ◽  
Content Type ◽  
Gastroenteritis Virus ◽  
Cellular Entry ◽  
Transmissible Gastroenteritis ◽  
Functional Receptor ◽  
The Way

ABSTRACTIdentification of cellular receptors used by coronavirus (CoV) entry into the host cells is critical to an understanding of pathogenesis and to development of intervention strategies. The fourth CoV genus,Deltacoronavirus, evolutionarily related to theGammacoronavirus, has just been defined recently. In the current study, we demonstrate that porcine aminopeptidase N (pAPN) acts as a cross-genus CoV functional receptor for both enteropathogenic porcine deltacoronovirus (PDCoV) and alphacoronovirus (AlphaCoV) (transmissible gastroenteritis virus [TGEV]) based upon three lines of evidence. First, the soluble S1 protein of PDCoV bound to the surface of target porcine cell lines known to express pAPN as efficiently as TGEV-S1, which could be blocked by soluble pAPN pretreatment. Second, both PDCoV-S1 and TGEV-S1 physically recognized and interacted with pAPN by coimmunoprecipitation in pAPN cDNA-transfected cells and by dot blot hybridization assay. Finally, exogenous expression of pAPN in refractory cells conferred susceptibility to PDCoV-S1 binding and to PDCoV entry and productive infection. PDCoV-S1 appeared to have a lower pAPN-binding affinity and likely consequent lower infection efficiency in pAPN-expressing refractory cells than TGEV-S1, suggesting that there may be differences between these two viruses in the virus-binding regions in pAPN. This study paves the way for dissecting the molecular mechanisms of PDCoV-host interactions and pathogenesis as well as facilitates future vaccine development and intervention strategies against PDCoV infection.IMPORTANCEThe emergence of new human and animal coronaviruses is believed to have occurred through interspecies transmission that is mainly mediated by a species-specific receptor of the host. Among the four genera of theCoronavirinae, a couple of functional receptors for the representative members in the generaAlphacoronavirusandBetacoronavirushave been identified, whereas receptors forGammacoronavirusandDeltacoronavirus, which are believed to originate from birds, are still unknown. Porcine coronaviruses, including the newly discovered porcine deltacoronavirus (PDCoV) associated with diarrhea in newborn piglets, have posed a serious threat to the pork industry in Asia and North America. Here, we report that PDCoV employs the alphacoronavirus TGEV functional receptor porcine aminopeptidase N (pAPN) for cellular entry, demonstrating the usage of pAPN as a cross-genus CoV functional receptor. The identification of the PDCoV receptor provides another example of the expanded host range of CoV and paves the way for further investigation of PDCoV-host interaction and pathogenesis.

scholarly journals Aminopeptidase N-null neonatal piglets are protected from transmissible gastroenteritis virus but not porcine epidemic diarrhea virus

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Lei Luo ◽  
Shaohua Wang ◽  
Lin Zhu ◽  
Baochao Fan ◽  
Tong Liu ◽  
...  
Keyword(s):  
Small Intestine ◽  
Porcine Epidemic Diarrhea Virus ◽  
Aminopeptidase N ◽  
Host Cells ◽  
Transmissible Gastroenteritis Virus ◽  
Diarrhea Virus ◽  
Neonatal Piglets ◽  
Gastroenteritis Virus ◽  
Porcine Epidemic Diarrhea ◽  
Transmissible Gastroenteritis

Abstract Swine enteric diseases have caused significant economic loss and have been considered as the major threat to the global swine industry. Several coronaviruses, including transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV), have been identified as the causative agents of these diseases. Effective measures to control these diseases are lacking. The major host cells of transmissible gastroenteritis virus and porcine epidemic diarrhea virus have thought to be epithelial cells on small intestine villi. Aminopeptidase-N (APN) has been described as the putative receptor for entry of transmissible gastroenteritis virus and porcine epidemic diarrhea virus into cells in vitro. Recently, Whitworth et al. have reported that APN knockout pigs are resistant to TGEV but not PEDV after weaning. However, it remains unclear if APN-null neonatal pigs are protected from TGEV. Here we report the generation of APN-null pigs by using CRISPR/Cas9 technology followed by somatic cell nuclear transfer. APN-null pigs are produced with normal pregnancy rate and viability, indicating lack of APN is not embryonic lethal. After viral challenge, APN-null neonatal piglets are resistant to highly virulent transmissible gastroenteritis virus. Histopathological analyses indicate APN-null pigs exhibit normal small intestine villi, while wildtype pigs show typical lesions in small intestines. Immunochemistry analyses confirm that no transmissible gastroenteritis virus antigen is detected in target tissues in APN-null piglets. However, upon porcine epidemic diarrhea virus challenge, APN-null pigs are still susceptible with 100% mortality. Collectively, this report provides a viable tool for producing animals with enhanced resistance to TGEV and clarifies that APN is dispensable for the PEDV infection in pigs.

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