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At least 19 recordsLinked to original sources

PubMed1992

Coronavirus infection in mink (Mustela vison). Serological evidence of infection with a coronavirus related to transmissible gastroenteritis virus and porcine epidemic diarrhea virus.

Antibodies to a transmissible gastroenteritis virus (TGEV)-related coronavirus have been demonstrated in mink sera by indirect immunofluorescence, peroxidase-linked antibody assays and immunoblotting. This is the first serological evidence of a specific coronavirus infection in mink. The putative mink coronavirus (MCV) seems to be widespread in the Danish mink population with a prevalence approaching 100%. Analysis by immunoblotting has shown that MCV is closely related to TGEV by the spike (S), matrix (M) and nucleoprotein (N) polypeptides. Furthermore, antibodies to MCV also cross-reacted with N and M polypeptides of porcine epidemic diarrhea virus (PEDV). Thus MCV may occupy an intermediate position between the TGEV group of coronavirus and PEDV. The possibility that MCV may be associated with syndromes of acute enteritis in preweaning mink is discussed.

Animals↗

PubMed2004

Relative rates of non-pneumonic SARS coronavirus infection and SARS coronavirus pneumonia.

BACKGROUND: Although the genome of severe acute respiratory syndrome coronavirus (SARS-CoV) has been sequenced and a possible animal reservoir identified, seroprevalence studies and mass screening for detection of subclinical and non-pneumonic infections are still lacking. METHODS: We cloned and purified the nucleocapsid protein and spike polypeptide of SARS-CoV and examined their immunogenicity with serum from patients with SARS-CoV pneumonia. An ELISA based on recombinant nucleocapsid protein for IgG detection was tested with serum from 149 healthy blood donors who donated 3 years previously and with serum positive for antibodies against SARS-CoV (by indirect immunofluorescence assay) from 106 patients with SARS-CoV pneumonia. The seroprevalence of SARS-CoV was studied with the ELISA in healthy blood donors who donated during the SARS outbreak in Hong Kong, non-pneumonic hospital inpatients, and symptom-free health-care workers. All positive samples were confirmed by two separate western-blot assays (with recombinant nucleocapsid protein and recombinant spike polypeptide). FINDINGS: Western-blot analysis showed that the nucleocapsid protein and spike polypeptide of SARS-CoV are highly immunogenic. The specificity of the IgG antibody test (ELISA with positive samples confirmed by the two western-blot assays) was 100%, and the sensitivity was 94.3%. Three of 400 healthy blood donors who donated during the SARS outbreak and one of 131 non-pneumonic paediatric inpatients were positive for IgG antibodies, confirmed by the two western-blot assays (total, 0.48% of our study population). INTERPRETATION: Our findings support the existence of subclinical or non-pneumonic SARS-CoV infections. Such infections are more common than SARS-CoV pneumonia in our locality.

Blood Donors↗

PubMed2006

Porcine innate and adaptative immune responses to influenza and coronavirus infections.

Both innate and adaptative immune responses contribute to the control of infectious diseases, including by limiting the spreading of zoonotic diseases from animal reservoirs to humans. Pigs represent an important animal reservoir for influenza virus infection of human populations and are also naturally infected by coronaviruses, an important group of viruses, which includes the recently emerged severe acute respiratory syndrome (SARS) virus. Studies on both innate and adaptative immune responses of pigs to influenza virus and coronaviruses contribute, therefore, to a better control of these infections in their natural hosts and will be briefly reviewed in this article. Pro-inflammatory cytokines, including type I interferon (IFN), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6), were found in lung secretions of influenza virus infected pigs, and correlated with the intensity of clinical signs, whereas prior vaccination against influenza strongly reduced the production of infectious virus and cytokines in the lungs upon challenge, which was associated with clinical protection. An early type I IFN production was also found in coronavirus infected pigs, including at mucosal sites. IFN induction by coronavirus is shown to involve interaction between a viral glycoprotein and a leukocyte subset, likely equivalent to plasmacytoid dendritic cells, present in the mucosae and associated lymphoid tissues. Given the IFN mediated antiviral and immunomodulatory effects, the use of IFN or IFN inducers may prove an efficient strategy for a better control of influenza virus and coronavirus infections in pigs. Because influenza and coronaviruses target mucosal surfaces, adaptative immune responses have to be characterized at mucosal sites. Thus, nasal and pulmonary antibody responses were analyzed in influenza virus infected or vaccinated pigs showing short-lived, but potentially protective local IgA and IgG antibody (Ab) responses. Interestingly, primary influenza virus infection induced long-lived increase of lung CD8(+) T cells and local lymphoproliferative responses. Pigs infected by a respiratory coronavirus (PRCV) showed virus-specific IgG Ab-secreting cells in the bronchial lymph nodes, whereas the transmissible gastroenteritis coronavirus (TGEV) induced more IgA Ab-secreting cells in gut tissues, which illustrates the importance of the route of antigen administration for inducing local immune effector mechanisms. Porcine viral infections provide, therefore, valuable models for evaluating the immune parameters that are important for controlling transmission of important viral zoonotic infections.

Animals↗

PubMed2003

Down-regulation of transcription of the proapoptotic gene BNip3 in cultured astrocytes by murine coronavirus infection.

Murine coronavirus mouse hepatitis virus (MHV) causes encephalitis and demyelination in the central nervous system of susceptible rodents. Astrocytes are the major target for MHV persistence. However, the mechanisms by which astrocytes survive MHV infection and permit viral persistence are not known. Here we performed DNA microarray analysis on differential gene expression in astrocyte DBT cells by MHV infection and found that the mRNA of the proapoptotic gene BNip3 was significantly decreased following MHV infection. This finding was further confirmed by quantitative reverse transcription-polymerase chain reaction, Western blot analysis, and BNip3-promoter-luciferase reporter system. Interestingly, infection with live and ultraviolet light-inactivated viruses equally repressed BNip3 expression, indicating that the down-regulation of BNip3 expression does not require virus replication and is mediated during cell entry. Furthermore, treatment of cells with chloroquine, which blocks the acidification of endosomes, significantly inhibited the repression of the BNip3 promoter activity induced by the acidic pH-dependent MHV mutant OBLV60, which enters cells via endocytosis, indicating that the down-regulation of BNip3 expression is mediated by fusion between viral envelope and cell membranes during entry. Deletion analysis showed that the sequence between nucleotides 262 and 550 of the 588-base-pair BNip3 promoter is necessary and sufficient for driving the BNip3 expression and that it contains signals that are responsible for MHV-induced down-regulation of BNip3 expression in DBT cells. These results may provide insights into the mechanisms by which MHV evades host antiviral defense and promotes cell survival, thereby allowing its persistence in the host astrocytes.

Animals↗

PubMed2004

Human monoclonal antibody as prophylaxis for SARS coronavirus infection in ferrets.

SARS coronavirus continues to cause sporadic cases of severe acute respiratory syndrome (SARS) in China. No active or passive immunoprophylaxis for disease induced by SARS coronavirus is available. We investigated prophylaxis of SARS coronavirus infection with a neutralising human monoclonal antibody in ferrets, which can be readily infected with the virus. Prophylactic administration of the monoclonal antibody at 10 mg/kg reduced replication of SARS coronavirus in the lungs of infected ferrets by 3.3 logs (95% CI 2.6-4.0 logs; p<0.001), completely prevented the development of SARS coronavirus-induced macroscopic lung pathology (p=0.013), and abolished shedding of virus in pharyngeal secretions. The data generated in this animal model show that administration of a human monoclonal antibody might offer a feasible and effective prophylaxis for the control of human SARS coronavirus infection.

Animals↗

PubMed1992

An experimental model for dilated cardiomyopathy after rabbit coronavirus infection.

A rabbit model for coronavirus-induced dilated cardiomyopathy is described. Acute rabbit coronavirus infection results in virus-induced myocarditis and congestive heart failure. Of the survivors of rabbit coronavirus infection, 41% had increased heart weight and heart weight-to-body weight ratios, biventricular dilation, myocyte hypertrophy, myocardial fibrosis, and myocarditis consistent with the development of dilated cardiomyopathy. These changes were also seen in the remaining 59% of the survivors, except that the degree of myocyte hypertrophy was reduced and only right ventricular dilation was present. In most survivors, myocarditis was usually mild (1-5 foci/transverse section), but in some cases it was severe (> 20 foci/transverse section). Interstitial and replacement fibrosis was more pronounced in the papillary muscles. These data suggest that rabbit coronavirus infection may progress to dilated cardiomyopathy.

Animals↗

PubMed1993

Coronavirus infection in cats.

Cats are susceptible to natural infection with several strains of feline coronavirus that may result in either effusive and noneffusive FIP disease or in subclinical to severe enteritis. Investigators are still unsure of the routes by which strains of coronavirus are transmitted between cats. Excretion of coronavirus by infected cats into the environment occurs by way of feces, oronasal secretions, and, possibly, urine. FIP coronavirus remains stable outside the host for as long as 3 to 7 weeks and is rapidly inactivated by most household disinfectants. Clinical diagnosis of coronavirus infection is made by evaluating the presenting history, physical findings, laboratory results, coronavirus antibody titers, and by excluding analogous disease. The presence of coronavirus antibodies can be used to screen cats for the presence of coronavirus infection and as an adjunct in diagnosing clinical coronavirus infection. A intranasal TS-FIPV vaccine that protects against natural coronavirus challenge is available for healthy cats 16 weeks of age or older.

Animals↗

PubMedDate not supplied

[The experimental coronavirus infection of monkeys].

The coronavirus (CV) infection has been reproduced on monkeys (Macaca mulatta) for the first time. The strain CVRM 281, obtained from rhesus monkey who died of the spontaneous CV injection, has been used for the infection. The experimental CV infection has a chronic current with periodical relapses and virus persistence. Gastrointestinal tract (enterocolitis) and respiratory tract (pneumonia) are damaged exhibiting characteristic histological lesions. The monkey model of the CV injection can be used to solve obscure questions of human one.

Animals↗

PubMed2004

Coronavirus infection of spotted hyenas in the Serengeti ecosystem.

Sera from 38 free-ranging spotted hyenas (Crocuta crocuta) in the Serengeti ecosystem, Tanzania, were screened for exposure to coronavirus of antigenic group 1. An immunofluorescence assay indicated high levels of exposure to coronavirus among Serengeti hyenas: 95% when considering sera with titer levels of > or = 1:10 and 74% when considering sera with titer levels of > or = 1:40. Cubs had generally lower mean titer levels than adults. Exposure among Serengeti hyenas to coronavirus was also confirmed by a serum neutralisation assay and an ELISA. Application of RT-PCR to 27 fecal samples revealed viral RNA in three samples (11%). All three positive fecal samples were from the 15 juvenile animals (<24 months of age) sampled, and none from the 12 adults sampled. No viral RNA was detected in tissue samples (lymph node, intestine, lung) from 11 individuals. Sequencing of two amplified products from the S protein gene of a positive sample revealed the presence of coronavirus specific RNA with a sequence homology to canine coronavirus of 76 and 78% and to feline coronavirus type II of 80 and 84%, respectively. Estimation of the phylogenetic relationship among coronavirus isolates indicated considerable divergence of the hyena variant from those in European, American and Japanese domestic cats and dogs. From long-term observations of several hundred known individuals, the only clinical sign in hyenas consistent with those described for coronavirus infections in dogs and cats was diarrhea. There was no evidence that coronavirus infection in hyenas caused clinical signs similar to feline infectious peritonitis in domestic cats or was a direct cause of mortality in hyenas. To our knowledge, this is the first report of coronavirus infection in Hyaenidae.

Age Factors↗

PubMed2004

Receptor-dependent coronavirus infection of dendritic cells.

In several mammalian species, including humans, coronavirus infection can modulate the host immune response. We show a potential role of dendritic cells (DC) in murine coronavirus-induced immune modulation and pathogenesis by demonstrating that the JAW SII DC line and primary DC from BALB/c mice and p/p mice with reduced expression of the murine coronavirus receptor, murine CEACAM1a, are susceptible to murine coronavirus infection by a receptor-dependent pathway.

Animals↗

PubMed1990

Concurrent cryptosporidium and coronavirus infections in an Arabian foal with combined immunodeficiency syndrome.

Combined immunodeficiency syndrome is an inherited disorder of the Arabian breed of horses. Affected foals usually die of infectious disease within the first few months of life, and the respiratory tract is the commonest site of infection. This report describes the clinical and pathological features of a case which showed signs of alimentary and respiratory infections. Intestinal infection by coronavirus (not previously recorded in cases of the syndrome) and cryptosporidia was identified. Histopathological evidence also suggested the presence of an adenovirus infection.

Animals↗

PubMed1994

Ultrastructure of human nasal epithelium during an episode of coronavirus infection.

The nasal epithelium from a young girl was examined by electron microscopy and found to be infected by coronavirus. Virions are seen within and outside the ciliated cells, but not outside or within the goblet cells or other cells of the nasal mucosa. Some virions are located near the microvilli, others in pockets in the apical cell membrane. The cytoplasm contains many small vesicles with a single virion, large apical vesicles containing hundreds of virions, and lysosome-like cytosomes with a moderate number of virions. Some virus-like particles devoid of an electron-dense interior are seen both in the cytosomes and extracellularly. Virus budding was observed in the Golgi apparatus but nowhere else in the cell. The ciliated cells seem not to be destroyed by the viruses, although in many cases the cilia are withdrawn into the cell body. The loss of cilia is likely to cause rhinorrhoea.

Child, Preschool↗

PubMedDate not supplied

[Seroepidemiological study of coronavirus infection in children and adults in St. Petersburg].

As the result of prolonged (17 years) observations of patients with acute respiratory infections hospitalized in basic departments of clinics of the Research Institute of Influenza, coronavirus infection was found to be the cause of respiratory diseases, on the average, in 12% of cases (in some years in 6.8% to 28.6% of cases). The analysis of extensive morbidity rates among different age groups of the population showed that children were affected by coronavirus infection 5-7 times more often than adults. Three year cycles of this infection were established. The periods of coronaviruses activation were accompanied by their detection in patient material by electron-microscopy, a sharp increase of immune response of patients as well as in the number of nosocomial infections and the proportion of the monoinfection of the coronavirus nature. Coronaviruses played the leading role among other viruses in the etiology of hospital respiratory infections. Mucosal antibodies to coronaviruses in the secretions of the nasal cavity proved to be more important than serum antibodies not only in protection from infection, but also in the pattern of clinical manifestations of the disease.

Acute Disease↗

PubMed2005

Serological responses in patients with severe acute respiratory syndrome coronavirus infection and cross-reactivity with human coronaviruses 229E, OC43, and NL63.

The serological response profile of severe acute respiratory syndrome (SARS) coronavirus (CoV) infection was defined by neutralization tests and subclass-specific immunofluorescent (IF) tests using serial sera from 20 patients. SARS CoV total immunoglobulin (Ig) (IgG, IgA, and IgM [IgGAM]) was the first antibody to be detectable. There was no difference in time to seroconversion between the patients who survived (n = 14) and those who died (n = 6). Although SARS CoV IgM was still detectable by IF tests with 8 of 11 patients at 7 months postinfection, the geometric mean titers dropped from 282 at 1 month postinfection to 19 at 7 months (P = 0.001). In contrast, neutralizing antibody and SARS CoV IgGAM and IgG antibody titers remained stable over this period. The SARS CoV antibody response was sometimes associated with an increase in preexisting IF IgG antibody titers for human coronaviruses OC43, 229E, and NL63. There was no change in IF IgG titer for virus capsid antigen from the herpesvirus that was used as an unrelated control, Epstein-Barr virus. In contrast, patients who had OC43 infections, and probably also 229E infections, without prior exposure to SARS CoV had increases of antibodies specific for the infecting virus but not for SARS CoV. There is a need for awareness of cross-reactive antibody responses between coronaviruses when interpreting IF serology.

Adult↗

PubMed2004

Multi-phase approach to eradicate enzootic mouse coronavirus infection.

Infections with mouse coronavirus (also known as mouse hepatitis virus, MHV) are common and prompt concern because the adverse research effects of infection have been well documented. The animal facility we describe had contained an enzootic infection of mouse coronavirus for more than a decade. Eradication of the virus had been tried with limited success in the past. With an increase in the populations of immune-compromised and transgenic animals elsewhere in the facility, eradication of the virus became a high priority. The affected animals were in multiple breeding colonies comprising more than 4000 mice representing more than 50 site-specific strains, lines, and sublines. A task force designed to ensure representation of all interested parties developed a multi-phase approach which included (a) culling of nonessential animals, (b) cessation of breeding, (c) testing and culling of individual animals, and (d) cross-fostering to clean dams. To date, all of the strains, lines, and sublines manipulated through this multi-phase eradication approach continue to test negative for mouse coronavirus. This multi-phase approach may be useful for other institutions attempting to eradicate mouse coronavirus.

Animal Husbandry↗

PubMed1992

An experimental model for myocarditis and congestive heart failure after rabbit coronavirus infection.

In a model for virus-induced myocarditis and congestive heart failure, rabbit coronavirus infection was divided into acute (days 2-5) and subacute (days 6-12) phases on the basis of day of death and pathologic findings. During the acute phase, the principal histologic lesions were degeneration and necrosis of myocytes, myocytolysis, interstitial edema, and hemorrhage. The severity of these changes increased in the subacute phase. Pleural effusion and congestion of the lungs and liver were also present at this time. Myocarditis was detected by day 9 and peaked by day 12. Heart weights and heart weight-to-body weight ratios were increased, and dilation of the right ventricular cavity became prominent early in infection and persisted. In contrast, dilation of the left ventricle occurred late in the subacute stage. Virus was isolated from infected hearts between days 2 and 12. These data suggest that rabbit coronavirus infection progresses to myocarditis and congestive heart failure.

Animals↗

PubMed2005

Protease-mediated enhancement of severe acute respiratory syndrome coronavirus infection.

A unique coronavirus severe acute respiratory syndrome-coronavirus (SARS-CoV) was revealed to be a causative agent of a life-threatening SARS. Although this virus grows in a variety of tissues that express its receptor, the mechanism of the severe respiratory illness caused by this virus is not well understood. Here, we report a possible mechanism for the extensive damage seen in the major target organs for this disease. A recent study of the cell entry mechanism of SARS-CoV reveals that it takes an endosomal pathway. We found that proteases such as trypsin and thermolysin enabled SARS-CoV adsorbed onto the cell surface to enter cells directly from that site. This finding shows that SARS-CoV has the potential to take two distinct pathways for cell entry, depending on the presence of proteases in the environment. Moreover, the protease-mediated entry facilitated a 100- to 1,000-fold higher efficient infection than did the endosomal pathway used in the absence of proteases. These results suggest that the proteases produced in the lungs by inflammatory cells are responsible for high multiplication of SARS-CoV, which results in severe lung tissue damage. Likewise, elastase, a major protease produced in the lungs during inflammation, also enhanced SARS-CoV infection in cultured cells.

Animals↗

PubMed1999

Translation from the 5' untranslated region (UTR) of mRNA 1 is repressed, but that from the 5' UTR of mRNA 7 is stimulated in coronavirus-infected cells.

Viral gene products are generally required in widely differing amounts for successful virus growth and assembly. For coronaviruses, regulation of transcription is a major contributor to these differences, but regulation of translation may also be important. Here, we examine the possibility that the 5' untranslated regions (UTRs), unique for each of the nine species of mRNA in the bovine coronavirus and ranging in length from 70 nucleotides (nt) to 210 nt (inclusive of the common 5'-terminal 65-nt leader), can differentially affect the rate of protein accumulation. When the natural 77-nt 5' UTR on synthetic transcripts of mRNA 7 (mRNA for N and I proteins) was replaced with the 210-nt 5' UTR from mRNA 1 (genomic RNA, mRNA for viral polymerase), approximately twofold-less N, or (N) CAT fusion reporter protein, was made in vitro. Twofold less was also made in vivo in uninfected cells when a T7 RNA polymerase-driven transient-transfection system was used. In coronavirus-infected cells, this difference surprisingly became 12-fold as the result of both a stimulated translation from the 77-nt 5' UTR and a repression of translation from the 210-nt 5' UTR. These results reveal that a differential 5' UTR-directed regulation of translation can occur in coronavirus-infected cells and lead us to postulate that the direction and degree of regulation is carried out by viral or virally induced cellular factors acting in trans on cis-acting elements within the 5' UTR.

5' Untranslated Regions↗