Complete genome sequence of bovine herpesvirus type 1.1 (BoHV-1.1) Los Angeles (LA) strain and its genotypic relationship to BoHV-1.1 Cooper and more recently isolated wild-type field strains

The Cooper and Los Angeles (LA) strains were the two original respiratory strains of bovine herpesvirus type 1.1 (BoHV-1.1) isolated in the 1950s from cattle with infectious bovine rhinotracheitis. We report the complete genome sequence for the BoHV-1.1 LA strain and compare it to the prototype Cooper strain and six wild-type BoHV-1.1 isolates. A nucleotide sequence divergence of 0.74% was noted across the two complete genomes, caused by 19 single-nucleotide polymorphisms (SNPs) involving 12 genes and insertions/deletions that primarily affected the number of repeats within reiterated repeat regions of the genome. Phylogenetic analysis revealed that Cooper and LA strains are genetically the most ancient strains from which all of the more-recently isolated field strains of BoHV-1.1 evolved.

Isolation of a naturally occurring vaccine/wild-type recombinant bovine herpesvirus type 1 (BoHV-1) from an aborted bovine fetus

Bovine herpesvirus type 1 (BoHV-1) causes various disease syndromes in cattle including respiratory disease and abortions. During an investigation into the potential role of BoHV-1 modified-live vaccines (MLV) causing diseases in cattle, we performed whole genome sequencing on six BoHV-1 field strains isolated at Cornell Animal Health Diagnostic Center in the late 1970s. Three isolates (two respiratory and a fetal) were identified as vaccine-derived isolates, having SNP patterns identical to that of a previously sequenced MLV virus that exhibited a deleted US2 and truncated US1.67 genes. Two other isolates (a respiratory and a fetal) were categorized as wild-type (WT) viruses based on their unique SNP pattern that is distinct from MLV viruses. The sixth isolate from an aborted fetus was a recombinant virus with 62% of its genome exhibiting SNPs identical to one of the above-mentioned WT viruses also recovered from an aborted fetus. The remaining 38% consisted of two blocks of sequences derived from the MLV virus. The first block replaced the UL9-UL19 region, and the second vaccine-derived sequence block encompassed all the genes within the unique short region and the internal/terminal repeats containing the regulatory genes BICP4 and BICP22. This is confirmatory evidence that recombination between BoHV-1 MLV and WT viruses can occur under natural conditions and cause disease. It is important in that it underscores the potential for the glycoprotein E negative (gE^-) marker vaccine used to eradicate BoHV-1 in some countries, to recombine with virulent field strains allowing them to capture the gE^- marker, thereby endangering the control and eradication programs.

New Chromogenic Substrates for Thrombin with Increased Specificity

Chromogenic substrates for thrombin with high specificity are necessary for several functional assays, especially for the performance of photometric PT and APTT. A new approach to improve the specificity of chromogenic peptide substrates is made coupling tripeptide sequences selective for thrombin to derivatives of 5-amino-2-nitro benzoic acid (ANBA). Especially when the chromophore’s side chain is substituted by amines or amino acids hydrolysis rates by other enzymes like kallikrein, plasmin or factor Xa are decreased significantly compared to corresponding para-nitroanilides of the same amino acid sequence. On the other hand, most of these compounds are still sensitive thrombin substrates. KM-values for thrombin and other enzymes are in the same order of magnitude as corresponding pNA-peptides. ANBA peptide substrates may be useful to measure thrombin selectively in a mixture of other proteases like plasmin, factor Xa or kallikrein and for the colorimetric determination of PT and APTT.

Questioning the Extreme Neurovirulence of Monkey B Virus (Macacine alphaherpesvirus 1)

Monkey B virus (Macacine alphaherpesvirus 1; BV) occurs naturally in macaques of the genus Macaca, which includes rhesus and long-tailed (cynomolgus) monkeys that are widely used in biomedical research. BV is closely related to the human herpes simplex viruses (HSV), and BV infections in its natural macaque host are quite similar to HSV infections in humans. Zoonotic BV is extremely rare, having been diagnosed in only a handful of North American facilities with the last documented case occurring in 1998. However, BV is notorious for its neurovirulence since zoonotic infections are serious, usually involving the central nervous system, and are frequently fatal. Little is known about factors underlying the extreme neurovirulence of BV in humans. Here we review what is actually known about the molecular biology of BV and viral factors affecting its neurovirulence. Based on what is known about related herpesviruses, areas for future research that may elucidate mechanisms underlying the neurovirulence of this intriguing virus are also reviewed.

Efficacy of the early administration of valacyclovir hydrochloride for the treatment of neuropathogenic equine herpesvirus type-1 infection in horses

OBJECTIVE To determine whether prophylactic administration of valacyclovir hydrochloride versus initiation of treatment at the onset of fever would differentially protect horses from viral replication and clinical disease attributable to equine herpesvirus type-1 (EHV-1) infection. ANIMALS 18 aged mares. PROCEDURES Horses were randomly assigned to receive an oral placebo (control), treatment at detection of fever, or prophylactic treatment (initiated 1 day prior to viral challenge) and then inoculated intranasally with a neuropathogenic strain of EHV-1. Placebo or valacyclovir was administered orally for 7 or 14 days after EHV-1 inoculation or detection of fever (3 horses/group). Effects of treatment on viral replication and clinical disease were evaluated. Plasma acyclovir concentrations and viremia were assessed to determine inhibitory concentrations of valacyclovir. RESULTS Valacyclovir administration decreased shedding of virus and viremia, compared with findings for control horses. Rectal temperatures and clinical disease scores in horses that received valacyclovir prophylactically for 2 weeks were lower than those in control horses. The severity of but not the risk for ataxia was decreased by valacyclovir administration. Viremia was decreased when steady-state trough plasma acyclovir concentrations were > 0.8 μg/mL, supporting the time-dependent activity of acyclovir. CONCLUSIONS AND CLINICAL RELEVANCE Valacyclovir treatment significantly decreased viral replication and signs of disease in EHV-1-infected horses; effects were greatest when treatment was initiated before viral inoculation, but treatment was also effective when initiated as late as 2 days after inoculation. During an outbreak of equine herpesvirus myeloencephalopathy, antiviral treatment may be initiated in horses at various stages of infection, including horses that have not yet developed signs of viral disease.

Genome sequence variation among isolates of monkey B virus (Macacine alphaherpesvirus 1) from captive macaques

Complete genome sequences of 19 strains of monkey B virus (Macacine alphaherpesvirus 1; BV) isolated from several macaque species were determined. A low level of sequence variation was present among BV isolates from rhesus macaques. Most variation among BV strains isolated from rhesus macaques was located in regions of repetitive or quasi-repetitive sequence. Variation in coding sequences (polypeptides and miRNAs) was minor compared to regions of non-coding sequences. Non-coding sequences in the long and short repeat regions of the genome did however exhibit islands of conserved sequence. Oral and genital isolates from a single monkey were identical in sequence and varied only in the number of iterations of repeat units in several areas of repeats. Sequence variation between BV isolates from different macaque species (different BV genotypes) was much greater and was spread across the entire genome, confirming the existence of different genotypes of BV in different macaque species.

Understanding Primate Herpesviruses

Viruses related to the herpes simplex viruses of humans are present in all nonhuman primate (NHP) species tested and cross species transmission has been documented. The herpesvirus present in macaques, Herpes B virus (BV) rarely causes disease in its natural macaque host. However, when transmitted to a nonnative host, BV has occasionally caused severe and even fatal disease if not treated immediately. Here we present a comprehensive review of the taxonomy, molecular biology, physiology, epidemiology, diagnosis and treatment of BV. We also summarizes what is known about related herpesviruses of other NHP species and the zoonotic potential of these viruses.

Bovine herpesvirus-1: Genetic diversity of field strains from cattle with respiratory disease, genital, fetal disease and systemic neonatal disease and their relationship to vaccine strains

Bovine herpesvirus-1 (BoHV-1) causes disease in cattle with varied clinical forms. In the U.S. there are two BoHV1 subtypes, BoHV-1.1 and BoHV-1.2b. Control programs in North America incorporate modified live (MLV) or killed (KV) viral vaccines. However, BoHV-1 strains continue to be isolated from diseased animals or fetuses after vaccination. It is possible to differentiate BoHV-1 wild-type from MLV vaccine strains by determining their single nucleotide polymorphism (SNP) patterns through either whole-genome sequencing or PCR sequencing of genomic regions containing vaccine-defining SNPs. To determine the BoHV-1 subtype in clinical isolates and their relationship to MLV strains, 8 isolates from varied clinical disease at three different laboratories in the U.S. were sequenced and phylogenetically analyzed. Five samples were isolated within the past 5 years from New York and 3 were archived samples recovered 35 years prior from Oklahoma and Louisiana. Based on phylogenetic analysis, four of the cases appeared to be due to an MLV vaccine: 3 cases of aborted fetuses and one neonate with systemic BoHV-1 disease. One aborted fetus was from a herd with no reported history of MLV vaccination in two years. The remaining four isolates did not group with any MLV vaccines: two were associated with bovine respiratory disease, one with vulvovaginitis, and a fourth was determined to be a BoHV-1.2b respiratory isolate. Recovery of BoHV-1.1 that is very closely related to an MLV vaccine virus from a herd not receiving vaccines in an extended period prior to its isolation suggests that MLV viruses may remain latent or circulate within herds for long periods.

Detection and characterization of viruses as field and vaccine strains in feedlot cattle with bovine respiratory disease

This study investigated viruses in bovine respiratory disease (BRD) cases in feedlots, including bovine herpesvirus-1 (BoHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine coronaviruses (BoCV) and parainfluenza-3 virus (PI3V). Nasal swabs were collected from 114 cattle on initial BRD treatment. Processing included modified live virus (MLV) vaccination. Seven BRD necropsy cases were included for 121 total cases. Mean number of days on feed before first sample was 14.9 days. Swabs and tissue homogenates were tested by gel based PCR (G-PCR), quantitative-PCR (qPCR) and quantitative real time reverse transcriptase PCR (qRT-PCR) and viral culture. There were 87/114 (76.3%) swabs positive for at least one virus by at least one test. All necropsy cases were positive for at least one virus. Of 121 cases, positives included 18/121 (14.9%) BoHV-1; 19/121 (15.7%) BVDV; 76/121 (62.8%) BoCV; 11/121 (9.1%) BRSV; and 10/121 (8.3%) PI3V. For nasal swabs, G-PCR (5 viruses) detected 44/114 (38.6%); q-PCR and qRT-PCR (4 viruses) detected 81/114 (71.6%); and virus isolation detected 40/114 (35.1%). Most were positive for only one or two tests, but not all three tests. Necropsy cases had positives: 5/7 G-PCR, 5/7 q-PCR and qRT-PCR, and all were positive by cell culture. In some cases, G-PCR and both real time PCR were negative for BoHV-1, BVDV, and PI3V in samples positive by culture. PCR did not differentiate field from vaccines strains of BoHV-1, BVDV, and PI3V. However based on sequencing and analysis, field and vaccine strains of culture positive BoHV-1, BoCV, BVDV, and PI3V, 11/18 (61.1%) of BoHV-1 isolates, 6/17 (35.3%) BVDV isolates, and 1/10 (10.0%) PI3V identified as vaccine. BRSV was only identified by PCR testing. Interpretation of laboratory tests is appropriate as molecular based tests and virus isolation cannot separate field from vaccine strains. Additional testing using sequencing appears appropriate for identifying vaccine strains.

Genome sequence of a pathogenic isolate of monkey B virus (species Macacine herpesvirus 1)

The only genome sequence for monkey B virus (BV; species Macacine herpesvirus 1) is that of an attenuated vaccine strain originally isolated from a rhesus monkey (BVrh). Here we report the genome sequence of a virulent BV strain isolated from a cynomolgus macaque (BVcy). The overall genome organization is the same, although sequence differences exist. The greatest sequence divergence is located in non-coding areas of the long and short repeat regions. Like BVrh, BVcy has duplicated Ori elements and lacks an ORF corresponding to the γ34.5 gene of herpes simplex virus. Nine of ten miRNAs and the majority of ORFs are conserved between BVrh and BVcy. The most divergent genes are several membrane-associated proteins and those encoding immediate early proteins.

A single viral gene determines lethal cross-species neurovirulence of baboon herpesvirus HVP2

Alpha-herpesviruses can produce more severe infections in non-natural host species than in their natural host. Isolates of the baboon alpha-herpesvirus Papiine herpesvirus 2 (HVP2) are either very neurovirulent in mice (subtype nv) or non-virulent (subtype ap), but no such difference is evident in the natural baboon host. Comparative genome sequencing was used to identify subtype-specific sequence differences (SSDs) between HVP2nv and HVP2ap isolates. Some genes were identified that despite exhibiting sequence variation among isolates did not have any SSDs, while other genes had comparatively high levels of SSDs. Construction of genomic recombinants between HVP2nv and HVP2ap isolates mapped the mouse neurovirulence determinant to within three genes. Construction of gene-specific recombinants demonstrated that the UL39 ORF is responsible for determining the lethal neurovirulence phenotype of HVP2 in mice. These results demonstrate that differences in a single viral gene can determine the severity of herpesvirus infection in a non-natural host species.

Genome sequence of a chimpanzee herpesvirus and its relation to other primate alphaherpesviruses

This study reports the complete genome sequence of chimpanzee herpesvirus (ChHV), an alphaherpesvirus isolated from a chimpanzee. Although closely related to human herpes simplex virus type 2 (HSV2), the level of sequence diversity confirms that ChHV is sufficiently distinct to be considered a member of a different virus species rather than a variant strain of HSV2. Phylogenetic comparison with other simplexviruses at several levels supports the hypothesis that HSV2 and ChHV co-evolved with their respective human and chimpanzee hosts and raises questions regarding the evolutionary origins of HSV1.

Poisson factor models with applications to non-normalized microRNA profiling

MOTIVATION

Next-generation (NextGen) sequencing is becoming increasingly popular as an alternative for transcriptional profiling, as is the case for micro RNAs (miRNA) profiling and classification. miRNAs are a new class of molecules that are regulated in response to differentiation, tumorigenesis or infection. Our primary motivating application is to identify different viral infections based on the induced change in the host miRNA profile. Statistical challenges are encountered because of special features of NextGen sequencing data: the data are read counts that are extremely skewed and non-negative; the total number of reads varies dramatically across samples that require appropriate normalization. Statistical tools developed for microarray expression data, such as principal component analysis, are sub-optimal for analyzing NextGen sequencing data.

RESULTS

We propose a family of Poisson factor models that explicitly takes into account the count nature of sequencing data and automatically incorporates sample normalization through the use of offsets. We develop an efficient algorithm for estimating the Poisson factor model, entitled Poisson Singular Value Decomposition with Offset (PSVDOS). The method is shown to outperform several other normalization and dimension reduction methods in a simulation study. Through analysis of an miRNA profiling experiment, we further illustrate that our model achieves insightful dimension reduction of the miRNA profiles of 18 samples: the extracted factors lead to more accurate and meaningful clustering of the cell lines.

AVAILABILITY

The PSVDOS software is available on request.

Complete genome sequence of the NVSL BoHV-1.1 Cooper reference strain

The only complete genome sequence available for bovine herpesvirus 1 (BoHV-1) is a composite sequence derived from four different BoHV-1.1 strains and one BoHV-1.2 strain. Such a chimeric genome sequence is problematic for molecular genetic studies on this virus. We report here the complete genome sequence for the BoHV-1.1 NVSL reference strain Cooper. Although similar to the published chimeric genome sequence, there are a number of nucleotide substitutions and deletions/insertions across the genome, many of which affect coding sequences.

The evolution of infectious agents in relation to sex in animals and humans: brief discussions of some individual organisms

The following series of concise summaries addresses the evolution of infectious agents in relation to sex in animals and humans from the perspective of three specific questions: (1) what have we learned about the likely origin and phylogeny, up to the establishment of the infectious agent in the genital econiche, including the relative frequency of its sexual transmission; (2) what further research is needed to provide additional knowledge on some of these evolutionary aspects; and (3) what evolutionary considerations might aid in providing novel approaches to the more practical clinical and public health issues facing us currently and in the future?

Structure and sequence of the saimiriine herpesvirus 1 genome

We report here the complete genome sequence of the squirrel monkey α-herpesvirus saimiriine herpesvirus 1 (HVS1). Unlike the simplexviruses of other primate species, only the unique short region of the HVS1 genome is bounded by inverted repeats. While all Old World simian simplexviruses characterized to date lack the herpes simplex virus RL1 (γ34.5) gene, HVS1 has an RL1 gene. HVS1 lacks several genes that are present in other primate simplexviruses (US8.5, US10-12, UL43/43.5 and UL49A). Although the overall genome structure appears more like that of varicelloviruses, the encoded HVS1 proteins are most closely related to homologous proteins of the primate simplexviruses. Phylogenetic analyses confirm that HVS1 is a simplexvirus. Limited comparison of two HVS1 strains revealed a very low degree of sequence variation more typical of varicelloviruses. HVS1 is thus unique among the primate α-herpesviruses in that its genome has properties of both simplexviruses and varicelloviruses.

Type I IFN response to Papiine herpesvirus 2 (Herpesvirus papio 2; HVP2) determines neuropathogenicity in mice

Isolates of baboon alpha-herpesvirus Papiine herpesvirus 2 (HVP2) exhibit one of two distinct phenotypes in mice: extremely neurovirulent or apathogenic. Previous studies implicated the type I interferon (IFN) response as being a major factor in controlling infection by apathogenic isolates. To further investigate the possibility that the host IFN-beta response underlies the pathogenicity of the two HVP2 subtypes, the susceptibility of mice lacking the IFN-beta receptor (IFNAR(-/-)) to infection was examined. Apathogenic isolates of HVP2 (HVP2ap) replicated in IFNAR(-/-) primary mouse dermal fibroblast (PMDF) cultures as well as neurovirulent (HVP2nv) isolates. IFNAR(-/-) mice were also susceptible to lethal infection by HVP2ap isolates. Unlike Balb/c or parental 129 mice, LD(50) and ID(50) values for HVP2ap were the same in IFNAR(-/-) mice indicating that in these mice infection always progressed to death. HVP2ap replicated in the skin at the site of inoculation and invaded dorsal root ganglia as efficiently as HVP2nv in IFNAR(-/-) mice. Since the virion host shutoff (vhs) protein encoded by the UL41 gene of herpes simplex virus has been implicated in circumventing the host IFN-beta response and the phenotype of UL41 deletion mutants of HSV is very similar to that of HVP2ap isolates, the UL41 gene was deleted from HVP2nv (Delta 41) and replaced with the UL41 ORF from HVP2ap (Delta 41C). Like the parental HVP2nv virus, the Delta 41C recombinant replicated efficiently in Balb/c PMDFs and did not induce a strong IFN-beta response. The neuropathogenicity of the Delta 41C recombinant was also the same as the parental HVP2nv virus in Balb/c mice, indicating that the vhs protein does not underlie the different neuropathogenic phenotype of HVP2ap and HVP2nv. In contrast, the Delta 41 deletion virus induced a strong IFN-beta response but was still able to undergo multiple rounds of replication in PMDF cultures, albeit at a slower pace than the parental HVP2nv. This was reflected in vivo as the Delta 41 mutant had an LD(50) equivalent to that of the parental HVP2nv virus although the time to death was longer. These results indicate that while the vhs protein is involved in preventing and/or suppressing an IFN-beta response, it is not responsible for the ability of HVP2nv to overcome IFN-beta induced resistance of uninfected cells and does not underlie the divergent pathogenicity of the two HVP2 subtypes in mice.

Diagnostic exercise: papulovesicular dermatitis in rhesus macaques (Macaca mulatta)

Eleven rhesus monkeys developed multifocal erythematous and a vesicular rash. Most recovered spontaneously, but a 21-year-old female became moribund and was euthanized. Findings were of vesicular dermatitis and widespread multifocal hemorrhagic necrosis of the lungs and other viscera, with intralesional intranuclear inclusions. Simian varicella virus was identified as the cause by polymerase chain reaction analysis and serologic testing.

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.

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.

Temporal progression of viral replication and gross and histological lesions in Balb/c mice inoculated epidermally with Saimiriine herpesvirus 1 (SaHV-1)

Saimiriine herpesvirus 1 (SaHV-1), an alphaherpesvirus enzootic in squirrel monkeys, is genetically related to monkey B virus and human herpes simplex virus (HSV). To study the temporal progression of viral spread and associated lesions, Balb/c mice were inoculated epidermally by scarification with a green fluorescent protein (GFP)-expressing recombinant strain of SaHV-1 and killed sequentially. Pinpoint ulcerative lesions in the inoculated epidermis progressed over a few days to unilateral or bilateral hindlimb paresis or paralysis, urinary and faecal incontinence, abdominal distension, hunched posture and eventual depression warranting euthanasia. Viral replication was present within epidermal keratinocytes, neurons of the dorsal root ganglia and thoracolumbar spinal cord, regional autonomic ganglia, lower urinary tract epithelium and colonic myenteric plexuses, as indicated by histological lesions and GFP expression. Almost all mice inoculated with 10(5) or 10(6) plaque-forming units (PFU) of SaHV-1 developed rapidly progressive disease. Two of eight mice given 10(4)PFU developed disease, but no mice receiving less than 10(4)PFU gave evidence of infection. Mice that showed no clinical signs also failed to develop an antiviral IgG response, indicating absence of active viral infection. For SaHV-1 inoculated epidermally, the ID(50), CNSD(50) and LD(50) values were identical (10(4.38)), indicating that successful infection by this route invariably resulted in lethal CNS (central nervous system) disease. Consistently severe disease in all infected animals, with regionally extensive distribution of viral replication, constituted a marked difference from the disease produced by intramuscular inoculation.

Clinicopathological characterization of monkey B virus (Cercopithecine herpesvirus 1) infection in mice

The purpose of this study was to establish a small animal model for monkey B virus (BV) infection. Mice were inoculated intramuscularly with several BV isolates. Comparisons were based upon the doses required to produce infection (ID50), non-central nervous system (CNS) clinical disease (CS50), CNS disease (CNSD50) and lethal effect (LD50). Strains differed in respect of the dose required to produce clinical disease in BALB/c mice. C57BL/6 mice were more resistant than BALB/c mice to CNS disease. Skin lesions at the inoculation site consisted of epidermal necrosis, ulceration, serocellular crusts and underlying dermatitis. CNS lesions included marked inflammation in the ipsilateral dorsal root ganglion and lumbar spinal cord (point of viral entry). The distribution of the lumbar spinal cord lesions suggested viral entry via sensory afferent neurons, ventral motor tracts, or both. The lesions in the more cranial spinal cord segments suggested ascension to the brain via bilateral spinothalamic and spinoreticular tracts. Brain lesions included encephalitis with neuronal necrosis and white matter destruction located consistently at the base of the brainstem, the reticular system, and rostrally to the thalamus and hypothalamus. Viral antigen was detected immunohistochemically in the lesions. The results indicated an ascending encephalomyelitis syndrome similar to that produced by BV in man.

Besteht ein Zusammenhang zwischen dem Schlafapnoesyndrom und der zirkadianen Häufung von Myokardinfarkten in den Morgenstunden?

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.

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.

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.

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.

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.

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.

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.

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.

Comparative pathology of infections with baboon and African green monkey alpha-herpesviruses in mice

The comparative pathology of Herpesvirus papio 2 (HVP2) of baboons and SA8 virus of African green monkeys relative to that of herpes simplex virus (HSV1) of man was investigated in young adult mice inoculated intramuscularly and observed for 21 days. The 50% infectious dose (ID(50)) for HVP2 was approximately 10(2.0) plaque-forming units (PFU), while the ID(50) for HSV1 and SA8 was 10(2.5) and 10(3.8), respectively. There were marked differences in the ability of these three viruses to invade the central nervous system (CNS) and cause clinical neurological disease. HSV1 produced neurological signs in a few animals given 10(6)PFU, but SA8 did not. In contrast, HVP2 readily invaded the CNS and produced fatal disease with doses as low as 10(2)PFU. Two isolates of HVP2 tested had a 50% CNS disease dose (CNSD(50)) of 10(2.5) and 10(3.0)PFU and an LD(50) of 10(3.8) and 10(4.3)PFU, respectively. Histopathological examination of tissue from HVP2-infected mice revealed severe lesions of inflammation and necrosis in the central, peripheral and autonomic nervous systems, as well as of other tissues including skin, adrenal glands and the gastrointestinal tract. Viral antigens were detected immunohistochemically in lesions. This study showed that while both HVP2 and SA8 could infect mice, there were marked differences in the ability of these two closely related viruses to cause clinical disease and CNS lesions. This murine model may prove useful in the investigation of viral or host determinants responsible for the varying neurovirulence of these simian alpha-herpesviruses.

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.

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.

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.

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.

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.

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.

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.

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.

Molecular evidence for distinct genotypes of monkey B virus (herpesvirus simiae) which are related to the macaque host species

Although monkey B virus (herpesvirus simiae; BV) is common in all macaque species, fatal human infections appear to be associated with exposure to rhesus macaques (Macaca mulatta), suggesting that BV isolates from rhesus monkeys may be more lethal to nonmacaques than are BV strains indigenous to other macaque species. To determine if significant differences that would support this supposition exist among BV isolates, we compared multiple BV strains isolated from rhesus, cynomolgus, pigtail, and Japanese macaques. Antigenic analyses indicated that while the isolates were very closely related to one another, there are some antigenic determinants that are specific to BV isolates from different macaque species. Restriction enzyme digest patterns of viral DNA revealed marked similarities between rhesus and Japanese macaque isolates, while pigtail and cynomolgus macaque isolates had distinctive cleavage patterns. To further compare genetic diversity among BV isolates, DNA sequences from two regions of the viral genome containing genes that are conserved (UL27 and US6) and variable (US4 and US5) among primate alphaherpesviruses, as well as from two noncoding intergenic regions, were determined. From these sequence data and a phylogenetic analysis of them it was evident that while all isolates were closely related strains of BV, there were three distinct genotypes. The three BV genotypes were directly related to the macaque species of origin and were composed of (i) isolates from rhesus and Japanese macaques, (ii) cynomolgus monkey isolates, and (iii) isolates from pigtail macaques. This study demonstrates the existence of different BV genotypes which are related to the macaque host species and thus provides a molecular basis for the possible existence of BV isolates which vary in their levels of pathogenicity for nonmacaque species.

Shedding and transmission of baboon Herpesvirus papio 2 (HVP2) in a breeding colony

Baboons in a captive breeding colony were monitored twice a year, and new additions were screened on arrival for shedding of Herpesvirus papio 2 (HVP2) and serologic reactivity to the agent. For 128 individual animals tested over a period of 1.5 years, shedding of infective virus was detected in 13 of 342 swab specimens (3.8%), each of these incidents representing shedding by a different animal. Among long-term colony animals, infective virus was recovered on only two occasions (5 of 236 swab specimens from five individuals). In all but one instance, animals shedding virus were infants, not adults, and all animals were shedding virus in the oral cavity. One of these five instances was an isolated case, but four (three infants and one adult) were clustered within a single breeding group. Molecular analyses of the HVP2 isolates from this cluster indicated that they likely arose from a single common source, probably the mother of one of the infants. None of 31 wild-caught baboons added to the colony during this period were found to be shedding infective virus, despite 93.5% of them being seropositive for HVP2. In contrast, 6 of 18 adult baboons (all seropositive) transferred into the colony from another breeding colony were found to be shedding HVP2 either orally (3 of 6) or genitally (3 of 6). In addition, 2 of 8 juvenile baboons in this shipment were found to be shedding virus in the oropharynx. Overall, 10 of 13 instances of HVP2 isolation were from the oropharynx rather than the genital tract, and 6 of 13 baboons shedding virus were infants or juveniles rather than adults. These results suggest that, although venereal transmission of HVP2 occurs among adult animals, oral infection of young, sexually immature baboons is not uncommon.

Effect of ethanol on postprandial duodenojejunal motility in humans

The effect of ethanol on postprandial small bowel motility was investigated in eight healthy volunteers using perfusion of nutrient solutions (17% proteins, 59% carbohydrates, 24% lipids) into the descending duodenum (5 ml/min for 120 min). An ethanol-containing solution (4% w/v, 4.06 kcal/min, 1190 mosmol/kg) was compared with the corresponding ethanol-free solution (2.64 kcal/min, 160 mosmol/kg) and another ethanol-free hyperosmolar solution adapted in caloric load and osmolality (4.06 kcal/min, 1160 mosmol/kg). Motility was recorded with a data logger and six pressure transducers at 3-cm intervals around the duodenojejunal flexure. Clustered contractions (27 +/- 4/hr) migrating aborally through the whole recording segment were the predominant motor pattern with ethanol compared with the ethanol-free (10 +/- 2/hr; P < 0.01) and the ethanol-free hyperosmolar solution (6 +/- 3/hr; P < 0.001). Other motility parameters with ethanol were not different from the ethanol-free solution, whereas the ethanol-free hyperosmolar solution showed a much less intense motor response. We conclude that ethanol does modify human postprandial duodenojejunal motility by inducing propagative motor patterns.

Detection and differentiation of primate alpha-herpesviruses by PCR

A rapid method for detection and differentiation of 5 primate alpha-herpesviruses (human herpes simplex virus types 1 and 2 [HSV1, HSV2], green monkey simian agent 8, baboon herpesvirus 2 [HVP2], and macaque B virus [BV]) was developed utilizing the polymerase chain reaction (PCR). PCR primers were located in conserved regions of the gene encoding the glycoprotein B, which flanks an intervening region that is highly divergent among the 5 viruses. Amplified PCR products from the 5 viruses were readily differentiated by their unique restriction enzyme digestion patterns. No variation in digestion patterns was noted among strains of HSV1, HSV2, or HVP2. One clinical isolate of BV exhibited variation in a single restriction site, but its overall restriction pattern remained typical of BV. This method (PCR/RFLP) allowed the presence of herpesvirus DNA in clinical swabs from primates to be readily detected and the virus unambiguously identified.

Prevalence of Herpesvirus papio 2 in baboons and identification of immunogenic viral polypeptides

The prevalence of Herpesvirus papio 2 (HVP2) in several groups of captive and wild-caught baboons was determined by detection of anti-HVP2 antibodies in 133 sera of adult baboons. Over 90% of newly imported (wild-caught) adult olive baboons (Papio anubis) from Kenya and chacma baboons (P. ursinus) from South Africa were found to have anti-HVP2 titers. Similarly, approximately 85% of captive breeding colony baboons (P. anubis and P. cynocephalus) were seropositive for HVP2. Infected animals were generally easily identifiable by enzyme-linked immunosorbent assay because anti-HVP2 IgG titers in immune animals were usually high (16,000 to 64,000). There was little variation in the relative reactivity patterns of individual HVP2-immune sera when tested against herpes simplex viruses 1 and 2, monkey B virus, H. cercopithecus 2, and HVP2, or against different HVP2 strains. Also, differences were not detected between reactivity of olive and chacma baboon immune sera. Analysis of the polypeptide specificity of immune sera by western blot identified four viral antigens that were consistent targets of immune sera. These antigens were the gB glycoprotein, a pair of unidentified glycoproteins of 80 to 100 kDa, the gD glycoprotein, and a series of smaller capsid proteins. Additional viral proteins were variably recognized by individual immune sera. The results of this study indicate that HVP2 is a common infection of baboons; there is little antigenic variation among HVP2 strains; and there are several HVP2 antigens that represent consistent targets of the anti-HVP2 immune response of baboons.

Ameloblastoma of the Maxilla: A Series of Three Cases

Ameloblastoma is an aggressive tumor of the maxilla. We reviewed several ameloblastomas of the maxilla that had been surgically removed. The English literature was reviewed to evaluate the appropriate treatment and success with these aggressive tumors.

Maxillary ameloblastoma is a tumor that can behave malignantly. There is a definite correlation between histopathologic appearance and tumor activity. The unicystic type of ameloblastoma responds well to complete resection. The treatment for an ameloblastoma of the maxilla is radical resection. Limited removal of the cyst/tumor initially is not adequate, and a secondary operation will be required. Ameloblastoma of the maxilla requires aggressive radical excision at the time of initial diagnosis.

Genetic and functional complementation of the HSV1 UL27 gene and gB glycoprotein by simian alpha-herpesvirus homologs

Utilizing co-transfection of DNA from glycoprotein gB- strain of HSV1 and cloned fragments of several simian alpha-herpesviruses containing the UL26, UL27 (gB glycoprotein), and UL28 gene homologs, replication-competent recombinant viruses were produced. Genetic analysis of one HSV1/SA8 recombinant (HSV1/SgB) demonstrated the presence of SA8 DNA comprising the entire UL27 (gB) gene and parts of the UL28 and UL26 ORFs in an otherwise HSV1 genome. The recombinant was shown to express the SA8 gB and p40 proteins (UL27 & UL26.5 gene products, respectively); all other proteins were indistinguishable from those of HSV1. The recombinant behaved like SA8 in gB-specific virus neutralization and cell surface antibody binding assays, while plaque morphology and replication kinetics were very similar to HSV1. Despite its overwhelming HSV1 genetic constitution, the recombinant displayed a pathogenic phenotype in mice very different from the parental HSV1. While HSV1 produced corneal disease in ocularly infected mice and readily spread to the nervous system. HSV1/SgB was markedly impaired in both respects. These results demonstrate the functional equivalency of the cercopithecine monkey virus gB glycoproteins and genes (including transcriptional regulatory elements) in HSV1, the functional nature of HSV1/SA8 chimeric UL28 and UL26 genes/proteins, and that UL28, gB and/or p40 proteins may effect the pathogenicity of HSV1.

Characterization of virus-specific and cross-reactive monoclonal antibodies to Herpesvirus simiae (B virus)

A panel of 13 monoclonal antibodies (MAbs) was produced that detect B virus (BV) proteins. Several of these MAbs were highly specific for BV, while the remainder cross-reacted in varying degrees with the other primate alphaherpesviruses. Utilizing western blot and radioimmunoprecipitation analysis, the MAbs were found to detect at least four distinct BV-infected cell antigens, several of which were composed of multiple polypeptides. One target antigen has been identified as the BV glycoprotein B (gB) homologue and was recognized by both virus-specific and cross-reactive MAbs. Although gB is an essential protein, none of the anti-gB MAbs neutralized infectious virus.