1
|
Osamudiamen FT, Akanbi OA, Oluwayelu DO, Bock CT, Klink P. Serological evidence of avian HEV antibodies in apparently healthy chickens in southwest Nigeria. PLoS One 2021; 16:e0247889. [PMID: 33635917 PMCID: PMC7909675 DOI: 10.1371/journal.pone.0247889] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 02/15/2021] [Indexed: 01/20/2023] Open
Abstract
Avian hepatitis E virus (aHEV) is associated with hepatitis-splenomegaly syndrome, big liver and spleen disease and hepatic rupture haemorrhage syndrome. However, the knowledge about aHEV in commercial layer chickens in Nigeria is scarce. In this study, 460 serum samples obtained from 36 apparently healthy commercial layer chicken flocks in three states (Ogun, Osun and Oyo States) of southwestern Nigeria were analysed by enzyme linked immunosorbent assay for the presence of anti-aHEV immunoglobulin Y (IgY) antibodies. In total, the overall seroprevalence of anti-aHEV antibodies was 14.6%. The serological analysis revealed that 75% of the flocks examined were positive for anti-aHEV IgY antibodies from chickens of various ages in all three states. The percentage of the seropositive chickens in the three states varied from flock to flock ranging from 60% to 88.8% and seropositive chickens were detected at any age (24-52 weeks of age) without significant differences between the age groups. This is the first report assessing the presence of aHEV antibodies in chickens from Nigeria. The detection of anti-aHEV antibodies in commercial layer chickens in this study emphasizes the importance of serosurveillance in disease monitoring due to the economic threat posed by aHEV as a result of decreased egg production and increased mortality in affected commercial layer chicken farms. However, further studies are essential to reveal the clinical implications and to assess the real burden of aHEV in Nigeria.
Collapse
MESH Headings
- Animals
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Chickens/blood
- Chickens/virology
- Cross-Sectional Studies
- Enzyme-Linked Immunosorbent Assay/veterinary
- Epidemiological Monitoring/veterinary
- Hepatitis E/blood
- Hepatitis E/epidemiology
- Hepatitis E/veterinary
- Hepatitis E/virology
- Hepatitis, Viral, Animal/blood
- Hepatitis, Viral, Animal/diagnosis
- Hepatitis, Viral, Animal/epidemiology
- Hepatitis, Viral, Animal/virology
- Hepevirus/immunology
- Immunoglobulins/blood
- Immunoglobulins/immunology
- Nigeria/epidemiology
- Poultry Diseases/blood
- Poultry Diseases/diagnosis
- Poultry Diseases/epidemiology
- Poultry Diseases/virology
- Seroepidemiologic Studies
- Splenic Diseases/blood
- Splenic Diseases/epidemiology
- Splenic Diseases/veterinary
- Splenic Diseases/virology
- Splenomegaly/blood
- Splenomegaly/epidemiology
- Splenomegaly/veterinary
- Splenomegaly/virology
Collapse
Affiliation(s)
- Fisayo Temilade Osamudiamen
- Department of Veterinary Microbiology, University of Ibadan, Ibadan, Nigeria
- Department of Infectious Diseases, Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Berlin, Germany
| | - Olusola Aanuoluwapo Akanbi
- Department of Infectious Diseases, Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Berlin, Germany
| | | | - C. -Thomas Bock
- Department of Infectious Diseases, Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Berlin, Germany
- Institute of Tropical Medicine, University of Tuebingen, Tuebingen, Germany
| | - Patrycja Klink
- Department of Infectious Diseases, Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Berlin, Germany
| |
Collapse
|
2
|
Japhet MO, Famurewa O, Adesina OA, Opaleye OO, Wang B, Höhne M, Bock CT, Mas Marques A, Niendorf S. Viral gastroenteritis among children of 0-5 years in Nigeria: Characterization of the first Nigerian aichivirus, recombinant noroviruses and detection of a zoonotic astrovirus. J Clin Virol 2018; 111:4-11. [PMID: 30580015 DOI: 10.1016/j.jcv.2018.12.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/14/2018] [Accepted: 12/16/2018] [Indexed: 11/18/2022]
Abstract
BACKGROUND Viruses are the leading cause of acute gastroenteritis in children worldwide. Understanding of the occurrence and genetic diversity of these viruses can help to prevent infections. OBJECTIVES The present study describes the presence, genetic diversity and possible recombination of five enteric viruses in children with gastroenteritis in Southwestern Nigeria. STUDY DESIGN From August 2012 to December 2013, stool samples and sociodemographic data of 103 diarrheic children <5 years were collected to detect and characterize rotavirus A, norovirus, human astrovirus, aichivirus and sapovirus using PCR techniques followed by sequencing and phylogenetic analyses. RESULTS At least one virus was identified in 58.3% (60/103) of the stool samples. Rotavirus, norovirus and astrovirus were detected in 39.8% (41/103), 10.7% (11/103), and 6.8% (7/103) respectively. Notably, aichivirus was detected for the first time in Nigeria (1/103; 0.97%). Sapovirus was not detected in the study. Co-infections with rotavirus were observed in eight samples either with norovirus or astrovirus or aichivirus. Phylogenetic analyses of different genome regions of norovirus positive samples provided indication for recombinant norovirus strains. A novel astrovirus strain closely related to canine astrovirus was identified and further characterized for the first time. CONCLUSIONS Viruses are the common cause of acute gastroenteritis in Nigerian infants with rotavirus as most frequently detected pathogen. New norovirus recombinants and a not yet detected zoonotic astrovirus were circulating in Southwestern Nigeria, providing new information about emerging and unusual strains of viruses causing diarrhea.
Collapse
Affiliation(s)
- M O Japhet
- Department of Microbiology, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria; Department of Microbiology, Faculty of Science, Ekiti State University, Ado-Ekiti, Ekiti State, Nigeria; Department of Infectious Diseases, Unit of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Berlin, Germany
| | - O Famurewa
- Department of Microbiology, Faculty of Science, Ekiti State University, Ado-Ekiti, Ekiti State, Nigeria; Department of Biological Sciences, Microbiology Unit, Kings University, Odeomu, Osun State, Nigeria
| | - O A Adesina
- Department of Microbiology, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
| | - O O Opaleye
- Department of Medical Microbiology and Parasitology, Ladoke Akintola University, Osogbo, Osun state, Nigeria
| | - B Wang
- Department of Infectious Diseases, Unit of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Berlin, Germany
| | - M Höhne
- Department of Infectious Diseases, Unit of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Berlin, Germany
| | - C T Bock
- Department of Infectious Diseases, Unit of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Berlin, Germany; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Andreas Mas Marques
- Department of Infectious Diseases, Unit of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Berlin, Germany
| | - S Niendorf
- Department of Infectious Diseases, Unit of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, Berlin, Germany.
| |
Collapse
|
3
|
Haussig JM, Nielsen S, Gassowski M, Bremer V, Marcus U, Wenz B, Bannert N, Bock CT, Zimmermann R. A large proportion of people who inject drugs are susceptible to hepatitis B: Results from a bio-behavioural study in eight German cities. Int J Infect Dis 2017; 66:5-13. [PMID: 29097248 DOI: 10.1016/j.ijid.2017.10.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/10/2017] [Accepted: 10/14/2017] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND People who inject drugs (PWID) are at high risk of hepatitis B virus (HBV) infection by sharing needles and drug use paraphernalia. In Germany, no routine surveillance of HBV prevalence and vaccination coverage among PWID exists. METHODS Socio-demographic and behavioural data were collected between 2011 and 2014 through face-to-face interviews, during a bio-behavioural survey of PWID recruited in eight German cities. Dried blood spots (DBS) prepared with capillary blood were tested for HBV markers. Factors associated with past/current HBV infection and vaccination status were analysed by univariable and multivariable analysis using logistic regression. The validity of self-reported HBV infection and vaccination status was analysed by comparison to the laboratory results. RESULTS Among 2077 participants, the prevalence of current HBV infection was 1.1%, of past HBV infection was 24%, and of vaccine-induced HBV antibodies was 32%. No detectable HBV antibodies were found in 43%. HBV infection status was significantly associated with study city, age, years of injecting, use of stimulants, migration status, and homelessness; HBV vaccination status was significantly associated with study city, age, and level of education. Correct infection status was reported by 71% and correct vaccination status by 45%. CONCLUSIONS HBV seroprevalence among PWID was about five times higher than in the general population in Germany, confirming PWID as an important risk group. Targeted information campaigns on HBV and HBV prevention for PWID and professionals in contact with PWID need to be intensified. Routinely offered HBV vaccination during imprisonment and opioid substitution therapy would likely improve vaccination rates among PWID.
Collapse
Affiliation(s)
- J M Haussig
- Postgraduate Training for Applied Epidemiology (PAE), Robert Koch Institute, Berlin, Germany; European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control, Stockholm, Sweden; Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | - S Nielsen
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany; Charité University Medicine, Berlin, Germany
| | - M Gassowski
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | - V Bremer
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | - U Marcus
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | - B Wenz
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | - N Bannert
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany
| | - C T Bock
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany
| | - R Zimmermann
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany.
| | | |
Collapse
|
4
|
Niendorf S, Jacobsen S, Faber M, Eis-Hübinger AM, Hofmann J, Zimmermann O, Höhne M, Bock CT. Steep rise in norovirus cases and emergence of a new recombinant strain GII.P16-GII.2, Germany, winter 2016. ACTA ACUST UNITED AC 2017; 22:30447. [PMID: 28181902 PMCID: PMC5388089 DOI: 10.2807/1560-7917.es.2017.22.4.30447] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 01/25/2017] [Indexed: 12/17/2022]
Abstract
Since early November 2016, the number of laboratory-confirmed norovirus infections reported in Germany has been increasing steeply. Here, we report the detection and genetic characterisation of an emerging norovirus recombinant, GII.P16-GII.2. This strain was frequently identified as the cause of sporadic cases as well as outbreaks in nine federal states of Germany. Our findings suggest that the emergence of GII.P16-GII.2 contributed to rising case numbers of norovirus gastroenteritis in Germany.
Collapse
Affiliation(s)
- S Niendorf
- Department of Infectious Diseases, Robert Koch-Institute, Berlin, Germany.,Consultant Laboratory for Noroviruses, Robert Koch-Institute, Berlin, Germany
| | - S Jacobsen
- Department of Infectious Diseases, Robert Koch-Institute, Berlin, Germany.,Consultant Laboratory for Noroviruses, Robert Koch-Institute, Berlin, Germany
| | - M Faber
- Department for Infectious Disease Epidemiology, Robert Koch-Institute, Berlin, Germany
| | - A M Eis-Hübinger
- Institute of Virology, University of Bonn Medical Centre, Bonn, Germany
| | - J Hofmann
- Institute of Medical Virology, Charité University Medicine, Berlin, and Labor Berlin, Charité-Vivantes GmbH, Berlin, Germany
| | - O Zimmermann
- Institute of Medical Microbiology, Göttingen, Germany
| | - M Höhne
- Department of Infectious Diseases, Robert Koch-Institute, Berlin, Germany.,Consultant Laboratory for Noroviruses, Robert Koch-Institute, Berlin, Germany
| | - C T Bock
- Department of Infectious Diseases, Robert Koch-Institute, Berlin, Germany
| |
Collapse
|
5
|
Wiegand J, Wedemeyer H, Franke A, Rößler S, Zeuzem S, Teuber G, Wächtler M, Römmele U, Ruf B, Spengler U, Trautwein C, Bock CT, Fiedler GM, Thiery J, Manns MP, Brosteanu O, Tillmann HL. Treatment of severe, nonfulminant acute hepatitis B with lamivudine vs placebo: a prospective randomized double-blinded multicentre trial. J Viral Hepat 2014; 21:744-50. [PMID: 24329913 DOI: 10.1111/jvh.12210] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 10/13/2013] [Indexed: 12/09/2022]
Abstract
Acute hepatitis B virus (aHBV) infection can lead to fulminant liver failure, which likely is prevented by early lamivudine therapy. Even nonfulminant but severe acute hepatitis B can lead to significant morbidity and impaired quality of life. Therefore, lamivudine was evaluated in patients with severe aHBV in a placebo-controlled trial. Patients with severe aHBV infection (ALT >10× ULN, bilirubin >85 μm, prothrombin time >50%) were prospectively treated with lamivudine 100 mg/day or with placebo within 8 days after the diagnosis. The primary end point was time to bilirubin <34.2 μm. Secondary end points were time to clear HBsAg and HBV-DNA, development of anti-HBs and normalization of ALT. Eighteen cases were randomized to lamivudine, 17 to placebo. 94% of patients were hospitalized. No individual progressed to hepatic failure; all but one patient achieved the primary end point. Due to smaller than expected patient numbers, all study end points did not become statistically significant between treatment arms. Median time end points [in days] were bilirubin <34.2 μm (26.5 vs 32), ALT normalization (35 vs 48) and HBsAg clearance (48 vs 67) referring to earlier recovery under lamivudine, in contrast to loss of HBV-DNA (62 vs 54) and development of anti-HBs (119 vs 109). In all but two patients (one in every group), HBsAg clearance was reached in the study. Adverse events occurred more frequently during lamivudine therapy, but did not reach statistical significance. Lamivudine may ameliorate severe aHBV infection, but limited patient numbers prevented definite conclusions.
Collapse
Affiliation(s)
- J Wiegand
- Universitätsklinikum Leipzig, Klinik für Gastroenterologie und Rheumatologie, Leipzig, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Ebinger M, Sotlar K, Weber A, Bock CT, Bültmann BD, Kandolf R. Simplified detection of microsatellite instability in colorectal cancer without the need for corresponding germline DNA analysis. J Clin Pathol 2006; 59:1114-5. [PMID: 17021141 PMCID: PMC1861765 DOI: 10.1136/jcp.2005.028217] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A panel of five quasimonomorphic mononucleotide repeats that dispenses with the need to analyse corresponding germline DNA was proposed by Suraweera et al for the detection of high-frequency microsatellite instability (MSI) in colorectal cancer. Using this panel, a simplified and a more sensitive (compared with the original) algorithm (p<0.05) was developed to define the instability of each repeat by assessing the morphological shape of its plot and not its absolute length. 103 cases of colorectal tumours were investigated and the results compared with those obtained by the analysis of five consensus microsatellites (Bethesda reference panel). By the proposed method, a higher specificity, but no loss of sensitivity, was found. Thus, the use of the five mononucleotide repeats in combination with the modified assessment technique simplifies the assessment of MSI, while retaining the sensitivity of the Bethesda panel for the detection of high-frequency MSI.
Collapse
Affiliation(s)
- M Ebinger
- Department of Haematology and Oncology, Children's Hospital, University of Tübingen, Tübingen, Germany.
| | | | | | | | | | | |
Collapse
|
7
|
Abstract
The human parvovirus B19 (PVB19), an erythrovirus causing diverse clinical manifestations ranging from asymptomatic or mild to more severe outcomes such as hydrops fetalis, is the only currently known human pathogenic parvovirus. Recently, PVB19 has been identified as a causative agent of pediatric and adult inflammatory cardiac diseases. The first hints for a possible etiopathogenetic role of the PVB19 infection and the development of cardiac dysfunction were demonstrated by molecular biology methods such as in situ hybridization (ISH) and polymerase chain reaction (PCR). In this regard, PVB19-associated inflammatory cardiomyopathy is characterized by infection of endothelial cells of small intracardiac arterioles and venules, which may be associated with endothelial dysfunction, impairment of myocardial microcirculation, and penetration of inflammatory cells in the myocardium.
Collapse
Affiliation(s)
- C T Bock
- Department of Molecular Pathology, Institute of Pathology, University Hospital of Tübingen, Germany.
| |
Collapse
|
8
|
Song LH, Duy DN, Binh VQ, Luty AJF, Kremsner PG, Bock CT. Low frequency of mutations in the X gene, core promoter and precore region of hepatitis B virus infected Vietnamese. J Viral Hepat 2005; 12:160-7. [PMID: 15720531 DOI: 10.1111/j.1365-2893.2005.00560.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Numerous mutations in the hepatitis B virus (HBV) genome have been described, but in most cases their role in the pathogenesis of HBV infection is still unclear. Therefore, we analysed specific mutations in HBV-infected Vietnamese patients and assessed their potential relationship with their clinical outcome. A total of 153 HBV-infected Vietnamese patients with well-characterised clinical profiles were enrolled. None of the study participants had a history of alcohol or drug use and none received any antiviral or immunosuppressive therapy before or during the course of this study. The HBx- and core promoter regions were analysed by sequencing. The majority of isolates corresponded to genotype A. The presence of hepatitis B e antigen (HBeAg) was associated with significantly higher viral loads in the chronic HBV-infection group (P = 0.026). Double mutations in the core promoter (1762/1764) were more frequent in those with cancer than in noncancer patients (P < 0.01). Mutations at nucleotide (nt) 1766/1773 were found at low prevalence but with no obvious association to clinical presentation. Cytosine at nt 1858 was predominant but the stop codon mutation in the precore region was not detected. In the study, 4/48 hepatocellular carcinoma (HCC) patients revealed truncated HBx, whilst the serine to alanine mutation (codon 31) of HBx was more prevalent in cancer patients than in asymptomatic HBV carriers (P < 0.01). Thus, the low frequency of mutations indicates the relation of the absence of antiviral pressure in this population. The exclusively found prevalence of certain mutations detected in those with HBV-related carcinoma nevertheless indicates a degree of association with disease progression.
Collapse
Affiliation(s)
- L H Song
- Department of Molecular Pathology, Institute of Pathology, University of Tuebingen, Tuebingen, Germany
| | | | | | | | | | | |
Collapse
|
9
|
Düx S, Lentini S, Bock CT, Klingel K, Kandolf R, Bauriedel G. [Parvovirus B19 myocarditis in a young man with previous non-bacterial meningitis]. Dtsch Med Wochenschr 2002; 127:1584-8. [PMID: 12143014 DOI: 10.1055/s-2002-32941] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
HISTORY AND CLINICAL FINDINGS A 22-year old man presented with fatigue, dyspnea NYHA III and presyncopes that had persisted since a non-bacterial meningitis 3 months before. INVESTIGATIONS Transthoracic echocardiography revealed a dilated left ventricle with an ejection fraction (EF) reduced to 35-40 % due to global hypokinesia. No pericardial effusion was seen; ECG and lung function test were normal. Serological, immunological and microbiological tests as well as nested PCR analysis of blood leucocytes for detection of cardiotropic pathogens were inconclusive. In endomyocardial biopsies retrieved from the left ventricular posterolateral wall, a chronic macro-phage-rich myocarditis was shown by histopathology and, in addition, Parvovirus B19 was identified as specific pathogen by use of nested PCR analysis. TREATMENT AND COURSE At physical rest and with ACE inhibitor therapy (2.5 mg ramipril/day), heart failure decreased steadily. Follow-up echocardiography 1 month later revealed a left ventricle that was only slightly dilated with an EF of 50 %. 3 months later, the patient was markedly more load-bearing; the EF amounted to 55-60 %. CONCLUSIONS Parvovirus B19 should be regarded as potential pathogen in case of suspected myocarditis in adulthood. Whether the previous non-bacterial meningitis was also attributable to this specific pathogen, remains open. Of note, however, the present case report by demonstrating a localized myocardial Parvovirus B19 infection without detectable systemic infection underscores the importance of molecular tests for diagnostic accuracy in manifest organ failure.
Collapse
Affiliation(s)
- S Düx
- Medizinische Klinik und Poliklinik II, Universitätsklinikum Bonn
| | | | | | | | | | | |
Collapse
|
10
|
Delaney WE, Edwards R, Colledge D, Shaw T, Torresi J, Miller TG, Isom HC, Bock CT, Manns MP, Trautwein C, Locarnini S. Cross-resistance testing of antihepadnaviral compounds using novel recombinant baculoviruses which encode drug-resistant strains of hepatitis B virus. Antimicrob Agents Chemother 2001; 45:1705-13. [PMID: 11353615 PMCID: PMC90535 DOI: 10.1128/aac.45.6.1705-1713.2001] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Long-term nucleoside analog therapy for hepatitis B virus (HBV)-related disease frequently results in the selection of mutant HBV strains that are resistant to therapy. Molecular studies of such drug-resistant variants are clearly warranted but have been difficult to do because of the lack of convenient and reliable in vitro culture systems for HBV. We previously developed a novel in vitro system for studying HBV replication that relies on the use of recombinant baculoviruses to deliver greater than unit length copies of the HBV genome to HepG2 cells. High levels of HBV replication can be achieved in this system, which has recently been used to assess the effects of lamivudine on HBV replication and covalently closed circular DNA accumulation. The further development of this novel system and its application to determine the cross-resistance profiles of drug-resistant HBV strains are described here. For these studies, novel recombinant HBV baculoviruses which encoded the L526M, M550I, and L526M M550V drug resistance mutations were generated and used to examine the effects of these substitutions on viral sensitivity to lamivudine, penciclovir (the active form of famciclovir), and adefovir, three compounds of clinical importance. The following observations were made: (i) the L526M mutation confers resistance to penciclovir and partial resistance to lamivudine, (ii) the YMDD mutations M550I and L526M M550V confer high levels of resistance to lamivudine and penciclovir, and (iii) adefovir is active against each of these mutants. These findings are supported by the limited amount of clinical data currently available and confirm the utility of the HBV-baculovirus system as an in vitro tool for the molecular characterization of clinically significant HBV strains.
Collapse
Affiliation(s)
- W E Delaney
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, Victoria 3051, Australia
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
The replicative intermediate of hepatitis B virus (HBV), the covalently closed, circular DNA, is organized into minichromosomes in the nucleus of the infected cell by histone and non-histone proteins. In this study we investigated the architecture of the HBV minichromosome in more detail. In contrast to cellular chromatin the nucleosomal spacing of the HBV minichromosome has been shown to be unusually reduced by approximately 10 %. A potential candidate responsible for an alteration in the chromatin structure of the HBV minichromosome is the HBV core protein. The HBV core protein has been implicated in the nuclear targeting process of the viral genome. The association of the HBV core protein with nuclear HBV replicative intermediates could strengthen this role. Our findings, confirmed by in vivo and in vitro experiments indicate that HBV core protein is a component of the HBV minichromosome, binds preferentially to HBV double-stranded DNA, and its binding results in a reduction of the nucleosomal spacing of the HBV nucleoprotein complexes by 10 %. From this model of the HBV minichromosome we propose that the HBV core protein may have an impact on the nuclear targeting of the HBV genome and be involved in viral transcription by regulating the nucleosomal arrangement of the HBV regulatory elements, probably in a positive manner.
Collapse
Affiliation(s)
- C T Bock
- Department of Gastroenterology and Hepatology, Medical School Hannover, Hannover, Germany.
| | | | | | | | | | | | | |
Collapse
|
12
|
Bock CT, Malek NP, Tillmann HL, Manns MP, Trautwein C. The enhancer I core region contributes to the replication level of hepatitis B virus in vivo and in vitro. J Virol 2000; 74:2193-202. [PMID: 10666249 PMCID: PMC111700 DOI: 10.1128/jvi.74.5.2193-2202.2000] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chronic hepatitis B virus (HBV) infection can lead to liver cirrhosis and hepatocellular carcinoma. Long-term interaction of the immune system with the virus results in the selection of escape mutants and viral persistence. In this work we characterize mutations in the enhancer I region isolated prior to liver transplantation from the HBV genomes of 10 patients with chronic HBV infection. The HBV-genomes were sequenced, and the enhancer I region was cloned into luciferase reporter constructs to determine the transcriptional activity. Functional studies were performed by transfecting HBV replication-competent plasmids into hepatoma cells. Analyses of the replication fitness of the mutant strains were conducted by biochemical analysis. In all HBV genomes the enhancer I region was mutated. Most of these mutations resulted in decreased transcriptional activity. The strongest effects were detectable in strains with mutations in the hepatocyte nuclear factor 3 and 4 (HNF3 and HNF4) binding sites of the enhancer I core domain. Replication-competent HBV constructs containing these mutations demonstrated up to 10-fold-reduced levels of virus replication. Before liver transplantation, when the mutant strains were detected in the patients' sera, low HBV DNA levels were found. After transplantation and reinfection with a wild-type virus, the levels of replication were up to 240-fold higher. Our results show that mutations in the enhancer I region of HBV have a major impact on HBV replication. These mutations may also determine the switch from high to low levels of viral replication which is frequently observed during chronic HBV infection.
Collapse
Affiliation(s)
- C T Bock
- Department of Gastroenterology and Hepatology, Medizinische Hochschule Hannover, D-30625 Hannover, Germany
| | | | | | | | | |
Collapse
|
13
|
Plümpe J, Malek NP, Bock CT, Rakemann T, Manns MP, Trautwein C. NF-kappaB determines between apoptosis and proliferation in hepatocytes during liver regeneration. Am J Physiol Gastrointest Liver Physiol 2000; 278:G173-83. [PMID: 10644576 DOI: 10.1152/ajpgi.2000.278.1.g173] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Tumor necrosis factor (TNF)-alpha is a potent inducer of apoptotic cell death in various tissues, whereas the transcription factor nuclear factor (NF)-kappaB is essential to protect against TNF-alpha-induced apoptosis. Human hepatoma cell lines were used to investigate the effectiveness and specificity of the fungal metabolite gliotoxin in inhibiting TNF-alpha-induced NF-kappaB activation in transformed cells. Gliotoxin-TNF-alpha cotreatment induced massive apoptosis in these otherwise TNF-alpha-resistant cell lines. With the use of the mouse partial hepatectomy model, we were also able to demonstrate in vivo the capacity of gliotoxin to act as inhibitor of NF-kappaB activation. Bromodeoxyuridine staining of liver sections showed that the lack of NF-kappaB activation correlated with 80% reduction of DNA synthesis 48 h after hepatectomy compared with untreated controls. Additionally, animals treated with gliotoxin showed nuclear condensation and DNA laddering of hepatocytes indicative of apoptosis 24 h after hepatectomy. In summary, our results demonstrate that NF-kappaB is essential in defining the fate of liver cells in response to TNF-alpha in vivo and furthermore implicate gliotoxin as a potential new response modifier for TNF-alpha-based therapy.
Collapse
Affiliation(s)
- J Plümpe
- Department of Gastroenterology and Hepatology, Medizinische Hochschule, 30625 Hannover, Germany
| | | | | | | | | | | |
Collapse
|
14
|
Cornberg M, Enss ML, Makkink MK, Beil W, Bock CT, Sobek-Klocke I, Mix H, Hiller W, Manns MP, Wagner S. Variation of human mucin gene expression in gastric cancer cell lines and gastric mucous cell primary cultures. Eur J Cell Biol 1999; 78:832-41. [PMID: 10604660 DOI: 10.1016/s0171-9335(99)80034-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Human gastric mucous cells - gastric cancer cell lines mucin gene expression - TNFalpha - RT-PCR immunocytochemistry Little is known on the expression pattern of mucin genes in human gastric cancer cell lines in relation to mucin expression in normal gastric epithelial cells. Thus, the aim of this study was to compare gastric cancer cell lines and non-transformed epithelial cells in their expression of the different mucin genes, in order to use these cells as models for physiological MUC expression in human stomach. Human gastric mucous cell primary cultures which were obtained from surgical specimen by collagenase/pronase treatment and a panel of six human gastric cancer cells were screened for mRNA expression of the mucin genes MUC1, MUC2, MUC5AC, MUC5B, and MUC6. Mucin gene expression was analyzed by semi-quantitative RT-PCR, and by Western blotting and immunocytochemistry. Primary cultured human gastric mucous cells retained the stomach-specific pattern of mRNA expression found in gastric mucosal biopsies (MUC1, MUC5AC, MUC6), whereas any gastric cancer cell line exhibited an aberrant mucin gene expression. Mucin gene expression showed large variations in levels and patterns from cell line to cell line, but MUC2 was aberrantly expressed in all cancer cells. Immunocytochemistry confirmed aberrant MUC2 protein expression in cancer cells. The expression of the secretory mucin genes MUC2 and MUC5AC varied in relation to the length of cultivation of the cancer cell lines. Treatment of the gastric cancer cells with TNFalpha resulted in an enhanced mRNA expression of MUC1, MUC2, and MUC5AC (2-fold increase within 3 hours; p <0.05). In contrast, immunocytochemistry disclosed a decrease in MUC2 and MUC5AC staining intensity. Our results indicate that primary cultured human gastric mucous cells provide a physiological in vitro system for investigations of gastric mucin gene regulation. In gastric cancer cells marked changes in the mucin gene expression pattern are found with coexpression of non-gastric type mucins. Gastric mucin gene expression may be regulated by proinflammatory cytokines which could have implications in gastritis.
Collapse
Affiliation(s)
- M Cornberg
- Department of Gastroenterology and Hepatology, Medizinische Hochschule Hannover, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Abstract
The functional role of the hepatitis B virus (HBV) pre-S region for assembly and appearance of the virus is not completely understood. In this study, 3 natural-occurring mutants were investigated. Three mutants of the pre-S region-a point mutation in the CCAAT box (MUT1), a 6-bp deletion (MUT2) 3' of the CCAAT box, and a 153-bp deletion (MUT3) in the preS2 domain-were cloned alone or in combinations in replication-competent HBV plasmids and transfected in hepatoma cells. The impact on HBV assembly and appearance was studied by Northern Blot, primer extension analysis, immunofluorescence studies, enzyme-linked immunosorbent assay, and electron microscopy. An inversed ratio of pre-S/S mRNA transcripts compared with wild-type (wt) HBV was found when either MUT1 or -2 were included into the plasmid. Intracellular localization with both mutants showed retention of large S-protein in the endoplasmic reticulum and nuclear accumulation of core protein. The extracellular amount of S-protein was reduced with MUT1 and -2 or combinations in which 1 of the mutants was included. However, the extracellular appearance of viral products was comparable with wtHBV. In contrast, MUT3 showed major changes. Virion-like particles had a fried-egg, and filaments a screw-like appearance. The S-promoter mutations MUT1 and MUT2 correlated with viral retention. MUT3 leads to malformed viral particles. Therefore, different regions in the pre-S domain are essential to determine the intracellular localization and extracellular appearance of HBV, and might contribute to the prognosis of chronic HBV infection.
Collapse
Affiliation(s)
- C T Bock
- Department of Gastroenterology and Hepatology, Medizinische Hochschule Hannover, Hannover, Germany
| | | | | | | |
Collapse
|
16
|
Bock CT, Kubicka S, Manns MP, Trautwein C. Two control elements in the hepatitis B virus S-promoter are important for full promoter activity mediated by CCAAT-binding factor. Hepatology 1999; 29:1236-47. [PMID: 10094970 DOI: 10.1002/hep.510290426] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Natural occurring mutations in the preS-region are frequently found during chronic hepatitis B virus (HBV) infection. Here we used the mutated preS-region from a patient to study the transcriptional regulation of the S-promoter. The mutations were a CCAAT-box (MUT1) point mutation, a 6-base pair (bp) deletion (MUT2) 3' of the CCAAT-box, and a 153 bp deletion (MUT3) in the preS2 genome. Transfection experiments revealed for MUT1 and 2 30% to 40% and MUT3 75% of the wildtype (wt) S-promoter activity. In electro-mobility shift assays experiments, binding of a nuclear protein was impaired with MUT1. Ultraviolet cross-linking, South-Western, and gel shift experiments revealed a 30- to 40-kd protein interacting with the wt CCAAT-motif. Computer-assisted analysis and supershift experiments showed that CCAAT-binding factor (CBF) is the CCAAT-box binding protein. Cotransfection experiments with expression vectors for dominant-negative CBF or wt CBF showed that the wt S-promoter but not MUT1 could be regulated through CBF. Additionally, the CBF constructs did not modulate the basal activity of MUT2 but changes the activity of MUT3 like wt HBV. Artificial mutations were introduced in the MUT2 reporter constructs. Transfection experiments revealed that wt promoter activity could not be reconstituted. Therefore these experiments indicated the sterical position of CBF being essential for full S-promoter activity. Our study shows that the CCAAT-box and a second region is essential to mediate full S-promoter activity dependent on CBF. As these mutations also lead to retention of S-protein in the endoplasmic reticulum our results indicate that mutational changes in the preS-region might be linked to the progression of HBV-related liver disease.
Collapse
Affiliation(s)
- C T Bock
- Department of Gastroenterology & Hepatology, Medizinische Hochschule, Hannover, Germany
| | | | | | | |
Collapse
|
17
|
Bock CT, Tillmann HL, Maschek HJ, Manns MP, Trautwein C. A preS mutation isolated from a patient with chronic hepatitis B infection leads to virus retention and misassembly. Gastroenterology 1997; 113:1976-82. [PMID: 9394738 DOI: 10.1016/s0016-5085(97)70018-0] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A preS mutation derived from a patient with chronic hepatitis B virus (HBV) infection who had HBV reinfection with fibrosing cholestatic hepatitis after orthotopic liver transplantation was characterized. Sequence analysis of the HBV genome revealed two deletions and a point mutation in the regulatory CCAAT element of the S promoter. To investigate the particular preS mutation for replication competence and viral assembly in functional experiments, the mutant preS region was introduced into a replication competent HBV plasmid. Functional studies were performed by transfecting this plasmid into hepatoma cells. Analysis of the mutant HBV strain revealed an inverse ratio of S-gene products in comparison to wild-type HBV that leads to intracellular viral retention. An atypical intracellular distribution of HBV proteins and an enhanced nuclear localization of HBV DNA was also detected. Additionally, a major fraction of the extracellular viral particles was malformed. The association of intracellular accumulation of viral proteins with cirrhosis and fibrosing cholestatic hepatitis has been described recently. In this study, we show that the particular preS mutation accounted for the viral retention, which may have contributed to a more progressive form of liver disease found in this HBV-positive patient after liver transplantation.
Collapse
Affiliation(s)
- C T Bock
- Department of Gastroenterology and Hepatology, Medizinische Hochschule Hannover, Germany
| | | | | | | | | |
Collapse
|
18
|
Wagner S, Beil W, Westermann J, Logan RP, Bock CT, Trautwein C, Bleck JS, Manns MP. Regulation of gastric epithelial cell growth by Helicobacter pylori: offdence for a major role of apoptosis. Gastroenterology 1997; 113:1836-47. [PMID: 9394723 DOI: 10.1016/s0016-5085(97)70003-9] [Citation(s) in RCA: 236] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND & AIMS Helicobacter pylori may affect the normal balance between gastric epithelial cell proliferation and epithelial cell death, thus interfering with the maintenance of gastric mucosal integrity. The aim of this study was to investigate the effect of H. pylori on cell growth, DNA synthesis, induction of apoptosis, and viability of human gastric epithelial cells in vitro. METHODS H. pylori was incubated with a differentiated human gastric cancer cell line for up to 72 hours, and the effects on cell numbers (cell counts and WST-1 assay), DNA synthesis (5-bromo-2'-deoxyuridine assay and [3H]thymidine incorporation), and DNA fragmentation (DNA fluorochrome staining, transmission electron microscopy, and histone enzyme-linked immunosorbent assay) were assessed. RESULTS Incubation of gastric epithelial cells with H. pylori led to a time- and concentration-dependent reduction of epithelial cell growth and a concomitant induction of DNA fragmentation. At high bacteria-cell ratios (> 100), inhibition of cell growth was associated with a reduction in DNA synthesis. Treatment of gastric cells with tumor necrosis factor alpha, a receptor-activating CD95/APO-1/Fas antibody, and interferon gamma markedly potentiated H. pylori-induced DNA fragmentation. CONCLUSIONS H. pylori affects gastric epithelial cell growth by direct induction of apoptosis and inhibition of DNA synthesis and indirectly by sensitization of epithelial cells for apoptosis induced by proinflammatory stimuli.
Collapse
Affiliation(s)
- S Wagner
- Department of Gastroenterology, Medizinische Hochschule Hannover, Germany. Wagner.Siegfried@MH-Hannover
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Abstract
An early step in the replication of the hepatitis B virus (HBV) genome is the transport of the viral DNA into the nucleus of the infected cell. So far only little is known about the events and mechanisms at the nuclear membrane required for entry of the viral genome into the nucleus. Using a hepatoblastoma cell line that constitutively produces hepatitis B virions and in so doing displays intracellular viral amplification, we showed that nonparticulated HBV core protein is associated with nuclear membrane pore complexes. Additionally, viral DNA has been detected firmly attached to the nuclear membrane. Small amounts of viral core protein, as well as viral DNA, were detectable within the cell nucleus. However, core particles could not be shown at the nuclear membrane or within the nuclei of these cells. Our observations on localization of HBV DNA and core protein at the nuclear membrane thus provide a suggestion for further examinations of the transfer of the viral genome from the cytoplasm into the nucleus of the infected cell.
Collapse
Affiliation(s)
- C T Bock
- German Cancer Research Centre, Applied Tumor Virology, Heidelberg, FRG
| | | | | | | | | |
Collapse
|
20
|
Bock CT, Schwinn S, Zentgraf H. Diheteroduplex formation using gold labeled single-stranded PCR fragments and its application in electron microscopy. Chromosoma 1995; 103:653-7. [PMID: 7587588 DOI: 10.1007/bf00357692] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Heteroduplex analysis is commonly used to map homologous sequences in DNA:DNA or DNA:RNA hybrids in spread preparations by electron microscopy. However, the standard procedures are not suitable to detect the orientation of a fragment with a defined sequence in a hybrid molecule. Here, we describe an alternative protocol for the visualization of DNA:DNA "diheteroduplex" structures based on digoxigenin/anti-digoxigenin gold labeling that allows determination of the position and orientation of a fragment. Single-stranded polymerase chain reaction (PCR) generated fragments labeled at their 3' ends are hybridized to double-stranded plasmid DNA. Electron microscopy of spread preparations visualizes the gold label and, in combination with morphometric measurements, it is possible to determine the position and orientation of the fragment with the diheteroduplex molecule.
Collapse
Affiliation(s)
- C T Bock
- German Cancer Research Center, Heidelberg, Germany
| | | | | |
Collapse
|
21
|
Montoliu L, Bock CT, Schütz G, Zentgraf H. Visualization of large DNA molecules by electron microscopy with polyamines: application to the analysis of yeast endogenous and artificial chromosomes. J Mol Biol 1995; 246:486-92. [PMID: 7877169 DOI: 10.1006/jmbi.1994.0100] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Standard visualization of nucleic acids by electron microscopy requires the use of special spreading techniques. The most common method takes advantage of the formation of a complex between negatively charged nucleic acid molecules and a positively charged monolayer film of proteins or cationic agents. Here, we describe an alternative protocol for the rapid visualization of DNA by electron microscopy based on the complexes formed when nucleic acids are exposed to buffers containing polyamines in the presence of sodium chloride. This procedure has been devised for the detection and analysis of large DNA molecules, such as yeast artificial chromosomes, but can be applied to DNA molecules of small size as well. The formation of DNA-polyamine complexes stabilizes large DNA molecules in solution and prevents shearing. This property allows large DNA molecules to remain intact after passage through microcapillaries used in the generation of transgenic mice by microinjection of fertilized eggs.
Collapse
Affiliation(s)
- L Montoliu
- Division of Molecular Biology of the Cell I, German Cancer Research Centre, Heidelberg
| | | | | | | |
Collapse
|
22
|
Abstract
Hepatitis B virus (HBV) nucleoprotein complexes were isolated from nuclei of the human hepatoblastoma cell line HepG2.2.15. Under conditions of physiological ionic strength, the complexes sedimented at a rate corresponding to about 82 S. They contained viral DNA, histone, and nonhistone proteins. For DNA a circular, covalently closed structure was shown both by CsCl gradient centrifugation and electron microscopy. Spread preparations revealed the typical "beads-on-a-string" appearance of nucleosomally organized DNA. The average number of nucleosomes was 18, resulting in a biochemical repeat unit of HBV chromatin of approximately 180 base pairs of DNA. This value was confirmed by experiments analyzing the structure of the HBV chromatin by the use of micrococcal nuclease. Electron microscopy demonstrated that exposure to high ionic strength conditions resulted in removal of nucleosomes from the complexes, but also revealed proteinaceous structures remaining bound to viral DNA molecules. The nature of these residual proteins is discussed. Since native nucleoprotein complexes could be precipitated with HBV-core antibodies, core protein appeared to be one of the nonhistone proteins.
Collapse
Affiliation(s)
- C T Bock
- German Cancer Research Centre, Heidelberg, FRG
| | | | | | | |
Collapse
|
23
|
Haun G, Keppler OT, Bock CT, Herrmann M, Zentgraf H, Pawlita M. The cell surface receptor is a major determinant restricting the host range of the B-lymphotropic papovavirus. J Virol 1993; 67:7482-92. [PMID: 8230469 PMCID: PMC238214 DOI: 10.1128/jvi.67.12.7482-7492.1993] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The B-lymphotropic papovavirus (LPV) productively infects only a subset of human B-lymphoma-derived cell lines while transfection of the viral genome yields infectious viral particles in a much wider variety of human hematopoietic cell lines. We have analyzed the contribution of a putative LPV receptor on the cell surface of B-cell lines in restricting the virus host range. In order to establish a quantitative virus binding assay for LPV, infectious virus particles were highly purified by metrizamide equilibrium density centrifugation and used as immunogens to raise seven mouse monoclonal antibodies specific for LPV VP1. Virus particle binding was quantitated in an indirect, nonradioactive assay with an LPV VP1-specific enzyme-linked immunosorbent assay. Binding of LPV particles to permissive human B-lymphoma cell line BJA-B occurred within minutes. Kinetics and capacity of binding were similar at 4 and 37 degrees C. A BJA-B cell was estimated to bind approximately 600 virus particles at conditions under which 50% of the administered virus was bound. The sialidase and trypsin sensitivities of the cellular virus binding moiety show that sialylated and proteinaceous components are necessary components of the LPV receptor on BJA-B cells. Despite a high binding capacity of BJA-B cells for simian virus 40, LPV binding was not significantly affected by a 20-fold excess of simian virus 40 particles, indicating that these related polyomaviruses do not bind to the same receptor on BJA-B cells. Reduction of LPV binding to sialidase-pretreated BJA-B cells was accompanied by a similar reduction of infection, indicating that virus binding may be a limiting factor in the LPV replicative cycle. The two highly LPV-permissive human B-lymphoma cell lines BJA-B and Namalwa displayed high virus binding whereas low and nonpermissive hematopoietic cell lines showed reduced or undetectable virus binding. We conclude that the inability of LPV particles to productively infect the nonpermissive human hematopoietic cell lines analyzed is probably due to the absence or insufficient expression of a functional cell surface receptor.
Collapse
Affiliation(s)
- G Haun
- Angewandte Tumorvirologie, Deutsches Krebsforschungszentrum, Heidelberg, Germany
| | | | | | | | | | | |
Collapse
|
24
|
Abstract
Electron microscopic examination of nucleic acids requires the use of special spreading techniques. The classical method was developed by Kleinschmidt and Zahn in 1959. Modifications of this method increased sensitivity to allow detection of a total amount of about 1 x 10(-3) micrograms of single-stranded DNA and 2 x 10(-5) micrograms of double-stranded DNA. Here we describe two rapid and simple procedures increasing sensitivity by 1-2 orders of magnitude to visualize at least 1 x 10(-5) micrograms of single- and/or double-stranded DNA.
Collapse
Affiliation(s)
- C T Bock
- Deutsches Krebsforschungszentrum, Angewandte Tumorvirologie (ATV), Heidelberg, Germany
| | | |
Collapse
|
25
|
Scherer G, Bock CT, Zentgraf H. Heteroduplex between an EMBL3 genomic clone and a lambda gt11 cDNA clone provides internal size standards. Nucleic Acids Res 1990; 18:4944. [PMID: 2144341 PMCID: PMC332009 DOI: 10.1093/nar/18.16.4944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- G Scherer
- Institute of Human Genetics, Freiburg, FRG
| | | | | |
Collapse
|