Biomedical subjects

R Eberle

Publications and source records attributed to R Eberle.

At least 19 recordsLinked to original sources

PubMed2006

Primary mouse dermal fibroblast cell cultures as an in vitro model system for the differential pathogenicity of cross-species herpesvirus papio 2 infections.

Infection of mice with herpesvirus papio 2 (HVP2) parallels zoonotic monkey B virus infections. A major benefit of the HVP2/mouse model is the existence of two HVP2 subtypes: HVP2nv rapidly invades and destroys the CNS while HVP2ap produces no clinical signs and mild histopathological lesions. However, in the natural baboon host, no difference in pathogenicity of HVP2 subtypes is evident. Primary dermal fibroblast cells were evaluated as a model system for defining virus-host interactions that influence the outcome of a cross-species infection. No differences in plaque formation or virus replication were observed between HVP2 subtypes in primary baboon dermal fibroblast cultures. In contrast, when primary mouse dermal fibroblasts (PMDF) were infected, HVP2nv replicated to higher titers and was more efficient at shutting down host-cell protein synthesis compared to HVP2ap. HVP2ap-infected PMDF cells produced more IFN-beta compared to HVP2nv, and IFN-beta pretreatment of PMDF cultures inhibited HVP2ap replication but did not affect HVP2nv. The differential pathogenicity of HVP2 subtypes in mice and the lack of such differences in the natural baboon host are recapitulated in the primary dermal fibroblast cell culture system. This model may prove useful in examining early, local, host responses that influence the outcome of cross-species infections.

Animals↗

PubMed2006

Neuropathogenesis of herpesvirus papio 2 in mice parallels infection with Cercopithecine herpesvirus 1 (B virus) in humans.

Cercopithecine herpesvirus 1 (monkey B virus; BV) produces extremely severe and usually fatal infections when transmitted from macaque monkeys to humans. Cercopithecine herpesvirus 16 (herpesvirus papio 2; HVP2) is very closely related to BV, yet cases of human HVP2 infection are unknown. However, following intramuscular inoculation of mice, HVP2 rapidly invades the peripheral nervous system and ascends the central nervous system (CNS) resulting in death, very much like human BV infections. In this study, the neurovirulence of HVP2 in mice was further evaluated as a potential model system for human BV infections. HVP2 was consistently neurovirulent when administered by epidermal scarification, intracranial inoculation and an eye splash. Quantitative real-time PCR, histopathology and immunohistochemistry were used to follow the temporal spread of virus following skin scarification and to compare the pathogenesis of neurovirulent and apathogenic isolates of HVP2. Apathogenic isolates were found to be capable of reaching the CNS but were extremely inefficient at replicating within the CNS. It is concluded that neurovirulent strains of HVP2 exhibit a pathogenesis in mice that parallels that observed in human BV infections and that this model system may prove useful in dissecting the viral determinants underlying the extreme severity of zoonotic BV infections.

Animals↗

PubMed2005

[Is there an association between the sleep apnea syndrome and the circadian peak of myocardial infarction in the morning hours?].

OBJECTIVE: To determine whether there is a relationship between the circadian rhythm of acute myocardial infarction (AMI) in the morning hours and the sleep apnea syndrome (SAS). PATIENTS AND METHODS: 203 patients who had sustained an AMI were examined 7-14 days later for sleep-associated breathing disorders using a 5-channel recording system. The diagnostic criterion for SAS was > 10 episodes of apnea and hypopnea per hour (AHI >10). 76 % of all patients were male, mean age 62 years. RESULTS: SAS was diagnosed in 91 of the 203 patients (44.8 %). Compared to the 112 patients without SAS there were significantly more AMI in the morning hours (6:00 am to 12:00 am) in the SAS-group (49.5 %) than in the non-SAS-group (21.4 %). The two groups differed with regard to the symptoms of day-time sleepiness (29.7 % vs 17.0 %), age (mean 64.6 years vs 60.2 years), gender (83.5 % vs 69.9 % male) and smoking (33.0 % vs 51.8 %). There were no significant differences in Body mass index, hypertension, hyperlipoproteinemia, diabetes mellitus, family history, history of cardiovascular disease and taking of sedatives. CONCLUSION: The strong association between SAS and morning onset of AMI found in this study could be the result of a sympathetic stress reaction to the breathing disorder.

Circadian Rhythm↗

PubMed2003

Alteration of the striatal dopaminergic system in human narcolepsy.

Striatal D2/D3 dopaminergic receptors have been proposed to play a role in cataplexy. The authors studied the striatal presynaptic dopamine transporter and postsynaptic D2-receptors in seven patients with narcolepsy and seven control subjects using [123I](N)-(3-iodopropene-2-yl)-2beta-carbomethoxy-3beta-(4-chlorophenyl)tropane and [123I](S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl)benzamide SPECT. D2-receptor binding was elevated in narcolepsy (p = 0.017) and correlated with the frequency of cataplectic and sleep attacks (R > or = 0.844, p < or = 0.017). The human striatal dopaminergic system is altered in vivo in narcolepsy/cataplexy.

Aged↗

PubMed2003

Construction and in vivo detection of an enhanced green fluorescent protein-expressing strain of Saimiriine herpesvirus 1 (SaHV-1).

Saimiriine herpesvirus 1 (SaHV-1) is an alpha-herpesvirus of squirrel monkeys used in mice to study neural pathogenesis of herpesviruses. To trace dissemination of virus from a peripheral site of inoculation to the central nervous system tissues, a recombinant strain of SaHV-1 expressing enhanced green fluorescent protein (GFP) was constructed by site-specific insertion of a GFP expression cassette into a transcriptionally null point in the SaHV-1 genome. PCR and Southern blot confirmed insertion of a single GFP expression cassette into the target site of the SaHV-1 genome. The recombinant virus was shown to produce strong fluorescence in the cytoplasm of infected cells in vitro. Growth kinetic experiments demonstrated no differences between recombinant and wild type SaHV-1 in producing infectious progeny virions. The recombinant virus was comparable to wild type SaHV-1 in development of clinical disease, microscopic lesions and induction of an antibody response in mice following intramuscular inoculation. Using confocal microscopy, GFP expression was easily observed in formalin fixed, paraffin-embedded tissues of mice infected with the recombinant SaHV-1. This simple specimen processing technique preserves tissue morphology and allows detection of viral replication within various tissues of experimentally infected animals.

Animals↗

PubMed2003

Isolation of cytomegalovirus and foamy virus from the drill monkey (Mandrillus leucophaeus) and prevalence of antibodies to these viruses amongst wild-born and captive-bred individuals.

Drill monkeys (Mandrillus leucophaeus) are an endangered species whose indigenous viral flora is largely unknown. We report here the isolation and characterization of both a cytomegalovirus (DrCMV) and a foamy virus (SFV-drl) from drill monkeys. Phylogenetic analysis of DNA sequence data placed the DrCMV within a primate CMV clade, and showed that SFV-drl was closely related to baboon foamy viruses. ELISA analysis demonstrated that DrCMV shared common epitopes with other primate CMVs but was distinct from human and baboon CMVs. ELISA testing of sera from wild-born and captive-bred drills indicated that the prevalence of antibodies reactive with these two viruses was 93.2% for DrCMV and 20.3% for SFV-drl.

Animals↗

PubMed2003

Sequence and genetic arrangement of the UL region of the monkey B virus (Cercopithecine herpesvirus 1) genome and comparison with the UL region of other primate herpesviruses.

The complete DNA sequence of the unique long (U(L)) region of monkey B virus (BV) was determined. Based on sequence homology and the presence of transcriptional control element motifs, homologues of every open reading frame present in the U(L) region of the Human herpesvirus 1 (herpes simplex virus 1, HSV-1) and Human herpesvirus 2 (herpes simplex virus 2, HSV-2) genomes were identified in BV. The BV genes are arranged in the same order and orientation as in HSV. These results demonstrate that the BV U(L) region is entirely co-linear with that of HSV-1 and HSV-2.

Animals↗

PubMed2003

Differential detection of B virus and rhesus cytomegalovirus in rhesus macaques.

Non-human primate herpesviruses establish and maintain a lifelong persistent infection in immunocompetent hosts in the absence of clinical signs of disease. A fundamental issue for understanding the natural history of non-human primate herpesviruses is whether the viruses are maintained in a truly latent state or one characterized by a low level of chronic expression. To address this issue, a real-time PCR assay was developed to quantify Cercopithecine herpesvirus type 1 (B virus) DNA in mucosal fluids of rhesus macaques. This assay was rapid, sensitive (10 genome copies) and specific for B virus obtained from multiple species of macaques. The shedding profile of B virus was compared to another endemic herpesvirus, rhesus cytomegalovirus (RhCMV), in colony-reared monkeys. Mucosal swabs or saliva samples were taken daily from two groups of seropositive monkeys undergoing either a stressful relocation (group 1) or daily chair restraint (group 2). B virus DNA was detected in mucosal fluids from four animals relocated during the breeding season (group 1) but not from 10 animals moved at other times of the year. No B virus DNA was detected in any group 2 monkey. In contrast, RhCMV DNA was detected in the majority of animals of both groups 1 and 2. Detection of B virus DNA shedding is a relatively rare event associated with the breeding season, while RhCMV DNA is persistently detected in mucosal fluids of most monkeys.

Animals↗

PubMed2003

Pathogenicity of different baboon herpesvirus papio 2 isolates is characterized by either extreme neurovirulence or complete apathogenicity.

In comparisons of the pathogenicity of simian alphaherpesviruses in mice, two isolates of the baboon virus HVP2 were nearly as lethal as monkey B virus, a biological safety level 4 agent (J. W. Ritchey, K. A. Ealey, M. Payton, and R. Eberle, J. Comp. Pathol. 127:150-161, 2002). To confirm these results, mice were inoculated intramuscularly with 10(5) PFU of HVP2 isolates obtained from different baboon subspecies and primate centers. Some of the HVP2 isolates (6 of 13) caused paralysis and death in the mice, while 7 of 13 HVP2 isolates produced no clinical signs of disease. The apathogenic HVP2 isolates (HVP2ap) induced only low levels of serum antiviral immunoglobulin G relative to levels observed in sera from mice infected with the neurovirulent isolates of HVP2 (HVP2nv). Histological examination of tissues from mice inoculated with HVP2nv isolates showed extensive neural tissue destruction, while mice infected with HVP2ap isolates showed no lesions. Tissue samples collected at 48-h intervals postinfection suggested that HVP2ap isolates failed to replicate at the site of inoculation. There was no significant difference in the in vitro replication, plaque size, or cytopathic effect morphology of HVP2ap versus HVP2nv isolates. While HVP2 isolates replicated better in Vero monkey kidney cells than in murine L cells, plaquing efficiency of individual isolates did not correlate with the dichotomous pathogenic properties seen in mice. Phylogenetic analyses of both coding and intergenic regions (US4-6) of the HVP2 genome separated isolates into two distinct clades that correlated with the two in vivo virulence phenotypes. Taken together, these results demonstrate that two subtypes of HVP2 exist that are very closely related but differ dramatically in their ability to cause disease in a murine model.

Animals↗

PubMed2002

Sequence and genetic arrangement of the U(S) region of the monkey B virus (cercopithecine herpesvirus 1) genome and comparison with the U(S) regions of other primate herpesviruses.

The sequence of the unique short (U(S)) region of monkey B virus (BV) was determined. The 13 genes identified are arranged in the same order and orientation as in herpes simplex virus (HSV). These results demonstrate that the BV U(S) region is entirely colinear with that of HSV type 1 (HSV-1), HSV-2, and simian agent 8 virus.

Amino Acid Sequence↗

PubMed2002

Detection of a unique genotype of monkey B virus (Cercopithecine herpesvirus 1) indigenous to native Japanese macaques (Macaca fuscata).

The Japanese macaque or snow monkey (Macaca fuscata) is an autochthonous monkey in Japan. It has long been assumed that the monkey population was not infected with Cercopithecine herpesvirus 1 (monkey B virus [BV]) since cases of human BV infection have never been reported in Japan. Although serologic testing of captive snow monkeys in Japan revealed antibodies to BV, it was thought that native Japanese macaques had either been infected with herpes simplex virus from humans or with BV from other imported macaque species. To clarify this issue, we performed polymerase chain reaction (PCR) analysis to amplify BV sequences from trigeminal ganglia of 30 Japanese macaque monkeys that were seropositive for BV. Sequences from two BV genes, UL27 (360 bp) and UL19 (1.0 Kbp), from 3 of 30 monkeys were amplified. Results of restriction fragment length polymorphism analysis and DNA sequencing of the fragments provided evidence that native Japanese macaques are infected with BV. Phylogenetic analysis indicated that these monkeys harbor their own genotype of BV that is different from other known BV genotypes, and provided additional evidence supporting the co-evolution of BV and macaques.

Animals↗

PubMed2001

Immunogenicity of a DNA vaccine against herpes B virus in mice and rhesus macaques.

Herpes B virus (Cercopithecine herpesvirus 1) is endemic in captive macaque populations and poses a serious threat to humans who work with macaques or their tissues. A vaccine that could prevent or limit B virus infection in macaques would lessen occupational risk. To that end, a DNA vaccine plasmid expressing the B virus glycoprotein B (gB) was constructed and tested for immunogenicity in mice and macaques. Intramuscular (IM) or intradermal (ID) immunization in mice elicited antibodies to gB that were relatively stable over time and predominately of the IgG2a isotype. Five juvenile macaques were immunized by either IM+ID (n=2) or IM (n=3) routes, with two booster immunizations at 10 and 30 weeks. All five animals developed antibodies to B virus gB, with detectable neutralizing activity in the IM+ID immunized animals. These results demonstrated that DNA immunization can be used to generate an immune response against a B virus glycoprotein in uninfected macaques.

Animal Husbandry↗

PubMed2001

Isolation and characterization of an endogenous cytomegalovirus (BaCMV) from baboons.

This report describes the isolation of CMV-like viruses from olive, yellow and chacma sub-species of baboons. The viruses were identified as CMVs by their characteristic growth properties in cell culture, virion morphology under the TEM, and antigenic cross-reactivity with other primate CMVs. The glycoprotein B gene homologue from an olive baboon CMV isolate (BaCMV OCOM4-37) was identified, cloned and sequenced. We present the sequence of this gene and by phylogenetic analysis demonstrate that BaCMV is in fact a cytomegalovirus, and is more closely related to rhesus CMV than to human CMV. An ELISA was developed to measure anti-BaCMV antibodies in baboon sera. Serological testing of colony-bred and wild-born baboons indicated that BaCMV is ubiquitous in all baboon populations, with >95% of adult baboons of all sub-species being infected.

Animals↗

PubMed2001

Characterization of gross and histological lesions in Balb/c mice experimentally infected with herpesvirus saimiri 1 (HVS1).

Accidental B virus (Herpesvirus simiae) infection of human beings working with macaques is frequently fatal. However, the pathogenic potential of other similar simian alphaherpesviruses, such as the squirrel monkey virus Herpesvirus saimiri (HVS1), is virtually unknown. As part of an effort to develop a murine model for infections with these agents, Balb/c mice were inoculated intramuscularly in the left hindlimb with 10 to 10(6) plaque forming units (PFU) of HVS1. After observation for clinical signs of infection for 21 days, mice were killed and specimens collected for serology and histopathology. Mice receiving 510(3) PFU of HVS1 exhibited severe, pruritic, ulcerative skin lesions near the site of inoculation and developed unilateral or bilateral hindlimb paralysis with severe muscle atrophy. Histological lesions were characterized by a necrotizing dermatitis and folliculitis. Spinal cord lesions consisted of a non-suppurative myelitis affecting primarily the ipsilateral dorsal horn of the thoracolumbar spinal cord with occasional extension to ventral and contralateral spinal cord regions. Immunohistochemical labelling confirmed the presence of viral antigen within the lesions, and anti-HVS1 IgG concentrations were related to the occurrence of disease. HVS1 infection in some mice extended from the ipsilateral dorsal horn and funiculus into the ventral and contralateral grey and white matter, resulting in bilateral hindlimb paralysis. Thoracolumbar spinal cord lesions resolved without continued spread of the virus to cranial nervous system structures, i.e., cervical spinal cord and brain.

Animals↗

PubMed2000

Simian foamy virus infections in a baboon breeding colony.

The prevalence, transmission, and variation of simian foamy viruses (SFVs) in baboons was investigated. Over 95% of adult baboons in the breeding colony as well as recently imported adult animals had high titers of anti-SFV serum IgG. Maternal antibody was detectable in infants' serum up to 6 months of age. Approximately 30% of infants in breeding harems experienced SFV infections by 1 year of age. Shedding of SFV in oral secretions was common, with 13% of samples from normal adult animals and 35% from immunosuppressed animals containing infectious SFV. SFV was isolated from three baboon subspecies (olive, yellow, and chacma baboons) and sequences from both the pol and the LTR regions of the provirus were amplified by PCR and sequenced. Phylogenetic analysis indicated that all baboon isolates formed a single lineage distinct from SFVs of other African monkey species. Within the baboon SFV lineage, two distinct clades were apparent, which consisted of isolates from yellow and olive baboons and isolates from chacma baboons. Competition ELISAs indicated that, while SFV isolates of these two groups were very closely related, antigenic differences do exist between them. SFV isolates from a drill and a mandrill were distinct from baboon SFV isolates, both genetically and antigenically.

Age Factors↗

PubMed2000

Retrospective analysis of an outbreak of B virus infection in a colony of DeBrazza's monkeys (Cercopithecus neglectus).

In 1981, an outbreak of herpetic disease developed in a colony of DeBrazza's monkeys (Cercopithecus neglectus). In seven of eight infected animals, clinical signs of infection included vesicular and ulcerative lesions on the lips, tongue, and/or palate. Histologic examination of lesions revealed intranuclear inclusion bodies, and electron microscopy revealed nucleocapsids and virions with typical herpesvirus morphology. Although a virus was isolated that appeared similar to monkey B virus, techniques available at the time did not allow precise identification of the virus. Analysis of serum from one surviving monkey collected 12 years after the outbreak revealed a pattern of reactivity characteristic of B virus-positive serum on the basis of results of ELISA and western immunoblot analysis. Polymerase chain reaction analysis of archived paraffin-embedded tissue specimens and molecular analysis of the one viral isolate obtained from a DeBrazza's monkey indicated that the virus responsible for the outbreak was a new genotype of B virus. Testing of sera from lion-tailed macaques (Macaca silenus) housed in an adjacent cage at the same zoo indicated that these animals harbored this virus and, thus, were the likely source of the virus that infected the DeBrazza's monkeys. This study documents usefulness of archiving samples from disease outbreaks for later analysis. In addition, this incident underscores the importance of considering herpes B virus infection when outbreaks of disease having characteristics of herpetic infections develop in nonhuman primates kept at institutions that also house macaques.

Animals↗

PubMed1999

Development of a competitive ELISA for detection of primates infected with monkey B virus (Herpesvirus simiae).

Two competitive ELISAs (C-ELISAs) are described that allow detection of antibodies against monkey B virus (BV, Cercopithecine herpesvirus 1). The assays utilize monoclonal antibodies (MABs) directed against the BV glycoprotein B (gB). Two of these MABs specifically recognize BV gB while a third MAB also reacts with the gB homologues of other primate alpha-herpesviruses (herpes simplexvirus-1, HSV-1: HSV-2; simian agent-8, SA8; and Herpesvirus papio-2, HVP2). A C-ELISA using the single cross-reactive MAB 3E8 allowed detection of host antibodies against HSV-1, HSV-2, SA8, HVP2 or BV, thus proving to be a sensitive assay for the detection of infection by any of these primate alpha-herpesviruses. The C-ELISA using BV-specific MABs was less sensitive but did allow some discrimination between infection by BV versus other alpha-herpesviruses. It was also shown that a C-ELISA using HVP2 as antigen and the cross-reactive MAB 3E8 was as sensitive for detection of BV antibody in macaque sera as an assay employing BV antigen. This test format allows detection of BV-infected primates without the biohazards associated with preparation and use of BV antigen.

Animals↗

PubMed1999

Herpesvirus papio 2: alternative antigen for use in monkey B virus diagnostic assays.

BACKGROUND AND PURPOSE: Serologic testing for antibody to monkey B virus (BV) in macaque sera is problematic due to the biohazardous nature of BV and BV antigens. Herpesvirus papio 2 (HVP2), a herpesvirus of baboons, is more closely related genetically and antigenically to BV than is human herpes simplex virus 1 (HSV1). The potential for use of HVP2 relative to HSV1 as an alternative test antigen for detection of anti-BV antibody in macaque sera was assessed. METHODS: Standard ELISA formats were developed, using BV-, HVP2-, and HSV1-infected cell extracts. Performance of the HVP2 and HSV1 tests was assessed relative to that of the BV test. RESULTS: Using the BV antigen ELISA, 349 sera from 7 macaque species were tested, and results were classified as positive (253), negative (94), or suspect (2). The ELISA using HVP2 antigen detected 98.0% of BV-positive sera (248 of 253), whereas the HSV1-based ELISA detected only 96.0% (243 of 253). All three ELISAs identified the same two samples as suspect, and the HSV1 ELISA identified three additional BV-positive sera as suspect. CONCLUSIONS: The HVP2 antigen-based ELISA was equal in sensitivity and specificity to the BV antigen-based ELISA and was superior to the HSV1 ELISA for detection of BV-positive macaque sera. In addition, the HVP2 ELISA has greater laboratory safety, compared with BV antigen use for ELISA testing.

Alphaherpesvirinae↗