The insulin degrading enzyme binding domain of varicella-zoster virus (VZV) glycoprotein E is important for cell-to-cell spread and VZV infectivity, while a glycoprotein I binding domain is essential for infection

Varicella-zoster virus (VZV) glycoprotein E (gE) interacts with glycoprotein I and with insulin degrading enzyme (IDE), which is a receptor for the virus. We found that a VZV gE deletion mutant could only be grown in cells expressing gE. Expression of VZV gE on the surface of cells did not interfere with VZV infection. HSV deleted for gE is impaired for cell-to-cell spread; VZV gE could not complement this activity in an HSV gE null mutant. VZV lacking the IDE binding domain of gE grew to peak titers nearly equivalent to parental virus; however, it was impaired for cell-to-cell spread and for infectivity with cell-free virus. VZV deleted for a region of gE that binds glycoprotein I could not replicate in cell culture unless grown in cells expressing gE. We conclude that the IDE binding domain is important for efficient cell-to-cell spread and infectivity of cell-free virus.     

Class-specific antibody responses to early and late antigens of varicella and herpes simplex viruses

Antibody responses to early antigens of varicella-zoster virus (VZV), simian varicella virus, and herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) were studied in primary, secondary, and latent infections. IgG antibody responses to the early antigens occurred in primary and secondary VZV and HSV infections, and antibodies to early antigens were also demonstrable in healthy individuals with latent VZV and HSV infections, indicating that the presence of antibodies to early antigens cannot be taken as evidence of active infection with the viruses. Patients with current VZV or HSV infections showed heterotypic IgG antibody responses to early antigens of VZV and HSV to the same extent as to late antigens. In all groups of patients, IgG antibody titers to early antigens were similar to those against the corresponding late antigens, and no difference was seen in the reactivity of early antigens produced with four different blocking agents (cytosine arabinoside, bromodeoxyuridine, trisodium phosphonoformate, and cycloheximide). Antibodies of the IgM and IgA classes reacted with both early and late antigens of HSV, but only with late antigens of VZV and simian varicella virus, suggesting that these antibodies may be directed against late proteins that are expressed to a greater extent in HSV-infected cells treated with blocking agents than they are expressed in treated VZV-infected cells. Homologous IgM antibody responses occurred in both primary and secondary VZV infections, but only in primary HSV infections. Heterotypic IgM responses to HSV-2 antigen were noted in a few VZV patients who did not have demonstrable IgG antibody to HSV, suggesting that even in patients without prior experience with HSV, a VZV infection may stimulate the production of IgM antibodies that react with antigens that are shared by VZV and HSV-2. IgA antibodies to late antigens of VZV and HSV were demonstrable in latent, as well as active, infections with these viruses.     

Further evidence for common antigens in herpes simplex and varicella-zoster viruses

To elucidate the mechanism of heterologous antibody responses to herpes simplex virus (HSV) and varicella-zoster virus (VZV) which occur in some patients with HSV or VZV infections, stronger evidence was sought for the existence of cross-reacting antibodies to these viruses, using antibody absorption procedures. Absorption of sera from initial HSV infections with HSV antigen was found to abolish heterologous antibody titer rises to VZV, as demonstrated in complement fixation, neutralization, and anti-complement immunofluorescence test systems. In most instances, convalescent-phase titers to heterologous VZV were reduced by HSV absorption to levels comparable to those in the acute-phase serum, indicating that cross-reacting antibodies were, in fact, responsible for the heterologous antibody titer rises. Absorption of convalescent-phase sera from HSV or VZV patients with homologous antigen also abolished or greatly diminished immunoprecipitating activity with the heterologous antigen, furnishing additional evidence of the existence of cross-reacting antibodies. Absorption of sera with insolubilized IgG to re-remove rheumatoid factor, which was present in a number of the sera studied, had no effect on either homologous or heterologous antibody titer increases. The demonstration of cross-reacting antibodies to HSV and VZV supports the concept that these two human herpesviruses share common antigen(s).     

Incidence of Alpha‐Herpes virus induced ocular disease in Suriname

Herpes simplex virus (HSV) infection of the corneal stroma is the most prominent cause of scar formation impairing visual acuity and HSV keratitis is the leading cause of corneal opacity throughout the world. Suriname lacked test systems for microbial causes of ocular disease, therefore a polymerase chain reaction‐based Herpes virus assay was introduced, enabling prompt recognition, and timely treatment, preventing progressive eye damage. The incidence and epidemiology of Herpes simplex virus type 1 (HSV‐1), type 2 (HSV‐2), and varicella zoster virus (VZV) in ocular disease in Suriname was assessed. In a cross‐sectional prospective study, ocular swabs were collected from 91 patients with a presumptive α‐Herpes virus ocular infection attending the Academic Hospital between November 2008 and August 2010 and were tested by a PCR‐based α‐Herpes virus assay. Alpha‐Herpes virus ophthalmic infections were caused predominantly by HSV‐1 with a prevalence of 31%. The prevalences of VZV, HSV‐2, and a mixed HSV‐1/HSV‐2 infection were 4%, 3%, and 2%, respectively. The first reported annual incidence of herpetic induced ocular disease in Suriname was estimated at 11.4 per 100,000 person‐years (95% CI, 4.8–18.1). No clear age, ethnic or gender dependent difference in incidence was observed. The information obtained on α‐Herpes virus positive ocular infections and the distribution of subtypes provided the first insight in the South American situation of α‐Herpes virus induced ocular disease. J. Med. Virol. 84:1937–1942, 2012. © 2012 Wiley Periodicals, Inc.     

Viral infections of the central nervous system in Spain: A prospective study

The aim of the study was to determine the incidence of viruses causing aseptic meningitis, meningoencephalitis, and encephalitis in Spain. This was a prospective study, in collaboration with 17 Spanish hospitals, including 581 cases (CSF from all and sera from 280): meningitis (340), meningoencephalitis (91), encephalitis (76), febrile syndrome (7), other neurological disorders (32), and 35 cases without clinical information. CSF were assayed by PCR for enterovirus (EV), herpesvirus (herpes simplex [HSV], varicella‐zoster [VZV], cytomegalovirus [CMV], Epstein–Barr [EBV], and human herpes virus‐6 [HHV‐6]), mumps (MV), Toscana virus (TOSV), adenovirus (HAdV), lymphocytic choriomeningitis virus (LCMV), West Nile virus (WNV), and rabies. Serology was undertaken when methodology was available. Amongst meningitis cases, 57.1% were characterized; EV was the most frequent (76.8%), followed by VZV (10.3%) and HSV (3.1%; HSV‐1: 1.6%; HSV‐2: 1.0%, HSV non‐typed: 0.5%). Cases due to CMV, EBV, HHV‐6, MV, TOSV, HAdV, and LCMV were also detected. For meningoencephalitis, 40.7% of cases were diagnosed, HSV‐1 (43.2%) and VZV (27.0%) being the most frequent agents, while cases associated with HSV‐2, EV, CMV, MV, and LCMV were also detected. For encephalitis, 27.6% of cases were caused by HSV‐1 (71.4%), VZV (19.1%), or EV (9.5%). Other positive neurological syndromes included cerebellitis (EV and HAdV), seizures (HSV), demyelinating disease (HSV‐1 and HHV‐6), myelopathy (VZV), and polyradiculoneuritis (HSV). No rabies or WNV cases were identified. EVs are the most frequent cause of meningitis, as is HSV for meningoencephalitis and encephalitis. A significant number of cases (42.9% meningitis, 59.3% meningoencephalitis, 72.4% encephalitis) still have no etiological diagnosis. J. Med. Virol. 85:554–562, 2013. © 2012 Wiley Periodicals, Inc.     

Reovirus type 3 synthesizes proteins in interferon-treated HeLa cells without reversing the antiviral state

Treatment of HeLa cells with human lymphoblastoid interferon (IFN-alpha) does not inhibit reovirus type 3 protein synthesis during virus infection. In contrast, reovirus translation is blocked by treatment of L cells with mouse IFN-alpha. The (2'-5')A synthetase activity is induced in HeLa cells by IFN-alpha treatment and is activated after reovirus infection, since cell lysates from these cells synthesize in vitro (2'-5')A oligonucleotides. The IFN-induced protein kinase activity is also triggered in those lysates upon dsRNA addition. Thus, contrary to DNA-containing viruses, such as vaccinia virus or adenovirus, reovirus infection does not destroy or reverse the IFN-induced antiviral state. In support of this conclusion, superinfection with poliovirus or vesicular stomatitis virus of reovirus-infected HeLa cells treated with IFN leads only to a blockade of translation of the former viruses. These results provide a remarkable example where in the same cells doubly infected with two different viruses, the antiviral state induced by IFN-alpha is manifested by selectively inhibiting translation of one kind of virus (poliovirus or vesicular stomatitis virus) without affecting the translation of reovirus type 3. In addition, these results indicate that the resistance of reovirus translation to inhibition by IFN is different from the mechanism of resistance induced by DNA-containing viruses.     

Distribution of varicella zoster virus and herpes simplex virus in disseminated fatal infections.

AIMS: To study the cutaneous and visceral distribution of herpes simplex virus (HSV) and varicella zoster virus (VZV) in fatal infections. METHODS: Standard histology, immunohistochemistry (monoclonal antibodies VL8 and VL2 and polyclonal antibody IE63 directed against VZV; monoclonal antibodies IBD4 and HH2 and polyclonal antibodies directed against HSVI and HSVII) and in situ hybridisation (anti-HSV and anti-VZV probes) were applied to formalin fixed, paraffin wax sections. RESULTS: On histological examination, Herpesviridae infection was evident in various organs including the lungs, liver and skin. In addition, immunohistochemistry and in situ hybridisation revealed the presence of HSV and VZV antigens and nucleic acids in several cell types and tissues showing no cytopathological alterations suggestive of Herpesviridae infection. The organs with histological evidence of infection also contained VZV or HSV antigens and their genes. CONCLUSIONS: These findings suggest that organ failure in disseminated VZV and HSV infections is primarily caused by HSV or VZV induced cell damage and lysis. They also indicate that immunohistochemistry and in situ hybridisation can provide an accurate, type-specific diagnosis on formalin fixed, paraffin wax embedded tissue even when classic histological and cytological characteristics are lacking.     

A comparison of the effects of cytotoxic cerebrospinal fluid on cell cultures with other cytopathogenic agents

Protein synthesis, antigen synthesis, and cell membrane permeability were analyzed after inoculating human diploid fibroblasts with control or cytotoxic CSF, herpes simplex virus type 1 (HSV 1), poliovirus 3, or Clostridium difficile toxin. Whereas protein synthesis and membrane permeability were affected by the viruses, and virus antigens detectable by pooled human serum were synthesized, the bacterial toxin and cytotoxic CSF did not induce any new proteins or antigens, although the cytotoxic CSF reduced cellular protein synthesis levels and caused an increase in the permeability of the cell membranes. The effect of the cytotoxic CSF in cell culture resembles that of a toxin rather than a replicating virus.     

Antibody response to herpes simplex virus glycoproteins gB and gD

The antibody response to herpes simplex virus (HSV) glycoproteins B and D was evaluated using these cloned glycoproteins in an ELISA assay and compared to a standard Western blotting procedure. The ELISA assay appeared to be more sensitive for detecting gB and gD antibodies. Antibodies to gB but not gD were detected in the acute sera of patients presenting with their first episode of true primary genital herpes. The geometric mean HSV gB titer (log 2) was also significantly higher than the geometric mean gD titer in the convalescent sera of these patients (7.9 +/- 0.7 vs. 5.5 +/- 0.9, P less than .003). A cross-reaction between HSV gB and varicella zoster virus (VZV) gp II was demonstrated. Thus, it is possible that a previous VZV infection could prime the immune system to respond rapidly and more vigorously to HSV gB. Indeed, in this report we demonstrated a significant correlation between the VZV ELISA absorbance and the titer to HSV gB and also detected a higher VZV ELISA absorbance and HSV gB titer in the acute sera of patients with a true primary HSV infection compared to other HSV seronegative VZV seropositive patients. Use of this quantitative assay should allow further investigation into the relationship of the immune response to these important targets and the clinical course of HSV disease.     

Assessing and restoring adaptive immunity to HSV,VZV, and HHV-6 in solid organ and hematopoietic cell transplant recipients

BackgroundHerpes simplex virus (HSV) 1 and 2, varicella zoster virus (VZV), and human herpesvirus 6 (HHV-6) cause severe infections in immunocompromised hosts. Interventions to optimize virus-specific adaptive immunity may have advantages over antivirals in the prophylaxis and treatment of these infections.ObjectivesWe sought to review adaptive immune responses and methods for assessing and replenishing cellular and humoral immunity to HSV, VZV, and HHV-6 in solid organ transplant and hematopoietic cell transplant recipients.SourcesWe searched PubMed for relevant studies on immune responses to HSV, VZV, and HHV-6 as well as studies describing methods for evaluating and restoring cell-mediated immunity to other double-stranded DNA viruses in transplant recipients. Recent studies, randomized controlled trials, and investigations highlighting key concepts in clinical virology were prioritized for inclusion.ContentWe describe the mechanisms of adaptive immunity to HSV, VZV, and HHV-6 and limitations of antivirals as prophylaxis and treatment for these infections in solid organ transplant and hematopoietic cell transplant recipients. We review methods for measuring and restoring cellular immunity to double-stranded DNA viruses; their potential applications to management of HSV, VZV, and HHV-6 in immunocompromised hosts; and barriers to clinical use. Vaccination and virus-specific T cell therapies are discussed in detail.ImplicationsThe growing repertoire of diagnostic and therapeutic techniques focused on virus-specific adaptive immunity provides a novel approach to management of viral infections in transplant recipients. Investigations to optimize such interventions specifically in HSV, VZV, and HHV-6 are needed.     

Specificity of skin test with varicella-zoster virus antigen in varicella-zoster and herpes simplex virus infections.

Specificity of the skin test with varicella-zoster virus (VZV) antigen was examined in guinea pigs infected with herpes simplex virus (HSV) type 1 or VZV and in children with a history of HSV infection who developed varicella. Infected guinea pigs responded positively only to homologous virus. No cross-reaction between HSV and VZV was detected in the skin test, as well as in the neutralization test in infected guinea pigs, suggesting that the VZV skin test is specific for immunity to VZV infection. Twelve children were infected with HSV during an HSV epidemic and subsequently developed varicella in institutional settings. During the 2.5-month period between the HSV and VZV infections, the immune status of the children to VZV was negative both in the skin test and in the antibody test, although antibody to HSV was detected by an immune adherence hemagglutination test. After VZV infection, all responded positively both in the skin test and in the antibody test (immune adherence hemagglutination test) to VZV. These results suggest that the VZV skin test is specific for immunity to VZV infection, not cross-reactive to HSV infection in humans. This specificity will be of value in screening susceptibility or immunity to VZV, irrespective of prior HSV infection.     

Antibodies against varicella-zoster virus and herpes simplex virus deoxythymidine kinase in heterologous infections

Antibody responses to varicella-zoster virus (VZV) deoxythymidine kinase (dTK) and herpes simplex virus (HSV) dTK in homologous and heterologous infections were studied. Antibodies blocking the enzymatic activity of VZV-dTK appeared late after varicella and decreased more or less in parallel with the decreasing complement fixing [CF] titre. In herpes zoster, on the other hand, antibodies to VZV-dTK appeared soon after infection. Antibodies against HSV dTKs appeared long after primary infection, but they were subsequently present in all other HSV-CF positive sera. In recurrent HSV, all acute sera were already HSV-dTK antibody positive, and three of nine persons showed an increase in titer between their acute and convalescent sera. Blocking antibodies to VZV-dTK appeared rapidly in specimens from three of 18 individuals positive by an immunofluorescence VZV-immunity test during HSV infection, whereas all other specimens remained devoid of blocking antibodies against VZV-dTK. A rise in antibody titre against HSV-dTK during VZV infections was observed in serum specimens from three of 13 HSV-CF positive patients, whereas an antibody response against HSV-dTK was not found in HSV-CF negative individuals in connection with VZV infections. The relevance of the sporadic increase in the titres of antibodies against heterologous viral dTKs is discussed.     

Direct immunofluorescence staining for detection of herpes simplex and varicella-zoster virus antigens in vesicular lesions and certain tissue specimens.

Direct immunofluorescence (IF) staining was compared with virus isolation for detection of herpes simplex viruses (HSV) and varicella-zoster virus (VZV) directly in clinical materials. These included 199 vesicular lesion specimens and 280 tissue specimens. Correspondence between IF and isolation results was 88% in testing for HSV in lesion specimens and 98% in testing for HSV in various tissue (mostly brain) specimens. Overall, IF was positive for 82% of the specimens in which HSV was demonstrated, and virus was isolated from 89% of the HSV-positive specimens. IF was markedly more sensitive than isolation for demonstrating VZV in lesion and tissue specimens, detecting all of the specimens positive for VZV, whereas isolation detected only 23%. IF detected VZV antigen in a number of lesion specimens taken late after onset, past the time when they would be expected to yield infectious virus. Specificity of positive IF reactions for HSV or VZV in the absence of virus isolation was supported by the facts that (i) staining was obtained with only a single, presumably homologous, immune conjugate, (ii) clinical symptoms were compatible with infection with the virus for which positive IF findings were obtained, and (iii) positive electron microscopy findings for herpesviruses or positive serological results for VZV were also obtained in some instances. Factors to be considered in achieving specificity of IF staining for these human herpesviruses are discussed.     

Genital Zoster Infection: the Great Imposter

Herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2), and varicella-zoster virus (VZV) are taxonomically closely related viruses that produce clinically distinct diseases but share common features of infection. HSV-1 and HSV-2 both produce cutaneous and mucocutaneous primary infections followed by reactivation disease occurring at the same or a nearby anatomic site. Primary VZV infection, also known as chickenpox, is usually a childhood disease that produces pox-like cutaneous lesions distributed over the entire body. Reactivation VZV infection, often called herpes zoster, generally occurs later in life but, unlike HSV disease, produces pox-like lesions at a different anatomic location, typically along dermatomes. As such, the clinical differential diagnosis of reactivation HSV infection and zoster is generally based upon the anatomic location and the appearance of the lesion(s). The recent availability of molecular assays has resulted in the unexpected diagnosis of zoster infections in male and female patients who presented with genital lesions. The purpose of this article is to present a brief overview of HSV and VZV infections and to relate a laboratory experience that resulted in the diagnosis of zoster infections using a molecular assay in which almost 10% of the 282 positive VZV specimens were from genital sites.     

Detection of both herpes simplex and varicella-zoster viruses in cerebrospinal fluid from patients with encephalitis

Cerebrospinal fluid (CSF) samples from 46 patients with encephalitis were studied for the presence of herpes simplex virus (HSV) types 1 and 2 and/or varicella zoster virus (VZV)-specific DNA sequences by the polymerase chain reaction (PCR) assay. Patients were studied because of detection of intrathecal production of IgG antibody to HSV alone (10 patients, Group A) or to both HSV and VZV (11 patients, Group B) or because of the presence of specific anti-HSV IgG in CSF without evidence of intrathecal antibody production (25 patients, Group C). CSF samples taken between days 1 and 10 from onset of encephalitis were available from all patients, and follow-up samples (taken after 10 days from onset) were obtained from some of them. Positive PCR results were obtained in a total of 13 patients. Four patients (three from Group A and one from Group B) gave amplification of HSV type 1 DNA alone, two patients (both from Group B) showed amplification of VZV DNA alone, and seven patients (all from Group B) gave dual amplification of both HSV type 1 and VZV DNA sequences in CSF. All CSF samples from patients in Group C were negative by PCR. Ten patients with CSF samples positive by PCR lacked a prior history of herpetic cutaneous lesions. In seven patients, serum antibody tests (specific IgM detection and specific IgG avidity assays) identified both primary and recurrent infections. The results suggest that the dual presence of IgG antibody to both HSV and VZV in CSF from patients with encephalitis may reflect in some cases a dual infection of the central nervous system caused by both agents. © 1996 Wiley-Liss, Inc.     

Studies on the defectiveness of adeno-associated virus (AAV). I. Effects of phosphonoacetic acid and 2-deoxy-D-glucose on the replication of AAV.

Adeno-associated viruses (AAV) are defective parvoviruses which require the presence of a helper virus, either an adenovirus or a herpesvirus, to initiate their replication cycle. The mechanisms by which these helper viruses can promote AAV macromolecular synthesis have been investigated in systems where the replication of the helper virus was altered. In the first system, phosphonoacetic acid (PAA), a specific inhibitor of herpesvirus-coded DNA polymerase, was used in AAV-herpes simplex virus (HSV) coinfections to determine what effect this drug would have on the replication of AAV. It was found that in the presence of increasing concentrations of PAA, the synthesis of AAV DNA, structural proteins, and immunofluorescent (IF) capsid antigens was inhibited. However, when an adenovirus helper was used in place of HSV, this inhibition was not seen. It was also found that the addition of the drug 5 hr after infection was still effective in inhibiting AAV capsid antigen synthesis completely. This finding indicates that the PAA-sensitive event required by AAV occurs relatively late in the HSV cycle. Restoration of HSV DNA polymerase activity by reversal of a PAA block was not sufficient for initiating AAV replication. De novo protein synthesis was required also. In the second system, the effects of 2-deoxy-d-glucose (2DG), an inhibitor of protein glycosylation, on AAV replication were also examined. In AAV coinfections with HSV, increasing concentrations of 2DG inhibited the production of AAV IF capsid antigens. Conversely, production of AAV intracellular proteins was enhanced with increasing 2DG concentrations. Under these conditions the pattern of IF staining for the major AAV polypeptide was normal. Thus 2DG appears to interfere with the assembly of AAV proteins into a capsid configuration. In experiments with an adenovirus helper, 2DG was found to inhibit initiation of AAV replication through early adenovirus functions.     

Herpesviral Fc receptors and their relationship to the human Fc receptors

Nearly two decades ago, it was observed that cells infected with herpes simplex virus (HSV) acquired an IgG Fc binding activity. The properties of the viral Fc receptor (FcR) have now been characterized by several laboratories. The Fc binding activity appears on the surface of the infected cell prior to formation of progeny virions. The FcR induced by HSV has been identified as the HSV glycoprotein, gE. When HSV gE forms a complex with a second HSV glycoprotein, gI, the receptor binds IgG with higher affinity. Varicella-zoster virus (VZV), which is closely related to HSV, has also been shown to induce an FcR. Like the HSV FcR, the FcR specified by VZV possesses characteristics common to viral glycoproteins. VZV encodes two glycoproteins, gpI and gpIV, which are the homologs of HSV gE and gI. The VZV glycoproteins have many properties common to cell surface receptors, including O-linked glycans and phosphorylation sites. However, extensive computer-assisted analyses of the amino acid sequences of VZV gpI and gpIV did not uncover regions of homology to the human cellular Fc receptors for IgG.     

Disseminated herpes simplex virus and varicella zoster virus coinfection in a patient taking thalidomide for relapsed multiple myeloma

Disseminated herpes simplex virus (HSV) and varicella zoster virus (VZV) have been reported individually in immunosuppressed adults. We present a case of coinfection with disseminated HSV and VZV infection in a patient taking thalidomide for relapsed multiple myeloma. This is the first report of opportunistic infection associated with thalidomide.     

Investigation of vesicular rashes for HSV and VZV by PCR

Vesicular fluid from rashes of 132 patients was tested by a multiplex PCR shown to be specific for herpes simplex virus (HSV) type 1 and 2, and varicella zoster virus (VZV) genomic DNA. The results were compared with those obtained by examination by electron microscopy and virus isolation by cell culture. The PCR did not differentiate between HSV 1 and 2. By PCR, 64 HSV infections and 53 VZV infections were identified, with presumed 100% sensitivity and specificity. Fifteen specimens tested negative by PCR, electron microscopy, and virus isolation for herpes viruses. The sensitivities of virus isolation and electron microscopy for detection of herpes simplex virus were 56% and 80%. For varicella zoster virus, the sensitivities of virus isolation and electron microscopy were 47% and 60%. These data illustrate the advantage of rapid PCR diagnosis of herpes simplex virus and varicella zoster virus in vesicle fluids. J. Med. Virol. 54:155–157, 1998. © 1998 Wiley-Liss, Inc.