herpes
Detection of intraocular antibody production to herpes viruses in acute retinal necrosis syndrome.

de Boer JH, Luyendijk L, Rothova A, Baarsma GS, de Jong PT, Bollemeijer JG, Rademakers AJ, Van der Lelij A, Zaal MJ, Kijlstra A.

The Netherlands Ophthalmic Research Institute, Amsterdam.

In order to improve the determination of the causative agent in acute retinal necrosis syndrome, we evaluated the detection of intraocular antibody production to herpes viruses in 28 patients with this disease. Intraocular antibody production was determined by calculation of the Goldmann-Witmer coefficient whereby specific antibody titers in the inflamed eye and circulation are related to the total IgG content in ocular fluid and serum. Specific antibody titers to herpes viruses and Toxoplasma were determined by the indirect immunofluorescence technique. Thirty-five patients with ocular toxoplasmosis, cataract, or proliferative vitreoretinal disorders were tested as controls. By this technique, intraocular antibody production to varicella zoster virus or herpes simplex virus could be established in 16 (57%) of the patients with the typical clinical features of acute retinal necrosis, compared to none of the controls. Of the 33 affected eyes, 21 (64%) had a visual outcome of less than 20/200. We concluded that detection of intraocular antibody production to herpes viruses may be a useful diagnostic tool in establishing the causative agents in acute retinal necrosis.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8116748&dopt=Abstract herpes medicine



herpes
The complete DNA sequence and the genetic organization of the short unique region (US) of the bovine herpes virus type 1 (ST strain).

Leung-Tack P, Audonnet JC, Riviere M.

Rhone Merieux, Laboratoire IFFA 254, Lyon, France.

The DNA sequence of bovine herpes virus type 1 (BHV-1) ST strain (BHV-1.2 subtype) entire unique short (US) region and part of adjacent flanking sequences of the inverted repeats was determined. The BHV-1 ST US region is 9745 bp in size and has a 70.5% G + C content. Eight potential open reading frames (ORFs) longer than 100 amino acids and designated ORF1 to ORF8 were identified on this sequence. Seven of these had counterparts in the US of herpes simplex type 1 (HSV-1), pseudorabies virus (PRV), and equine herpes virus type 1 (EHV-1). BHV-1 ORF2 encodes a protein homologous to HSV-1 US2; ORF3 putative protein exhibits homology with HSV-1 US3 (serine-threonine protein kinase); ORF4 encodes a putative glycoprotein homologous to PRV gG (gX) and EHV-1 gG (gX); ORFs 5,6, and 7 encode respectively HSV-1 glycoproteins gD, gl, and gE homologues; and ORF8 codes for a putative homologue of HSV-1 US9. Although BHV-1 ST strain apparently lacks a HSV-1 US1 homologue, the genetic content and the genomic organization of its US region was found to be similar to the general organization already described for HSV-1, EHV-1, PRV, and avian herpes viruses HVT and MDV US regions. In fact, the BHV-1 US region genomic organization is the closest to the general consensus determined from the comparison of known alphaherpes virus US regions.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8122370&dopt=Abstract herpes medicine



herpes
Characterization of the bovine herpes virus 1 homolog of the herpes simplex virus 1 UL24 open reading frame.

Whitbeck JC, Lawrence WC, Bello LJ.

Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104-6049.

An open reading frame (ORF) of 293 codons which partially overlaps the bovine herpes virus 1 (BHV1) thymidine kinase (tk) ORF in a head-to-head orientation has been identified by nucleotide sequence analysis. The predicted amino acid sequence of this ORF exhibits an overall identity of 38.1% with that of the herpes simplex virus type 1 (HSV1) UL24 ORF as well as an 80.7% identity with the 57-amino-acid consensus sequence found in the UL24-like ORFs of eight herpes viruses (Jacobson et al., J. Virol, 49, 947-959, 1989). We have therefore designated this BHV1 ORF as the homolog of the HSV1 UL24 ORF with which it also shares a common position and orientation relative to the tk ORF. The BHV1 UL24-like ORF is contained within a 5.2-kb RNA transcript initiating within the tk ORF and is the largest in a group of four 3'-coterminal transcripts. This transcript pattern closely resembles that observed in HSV1-infected cells where five transcripts, the two largest of which contain the UL24 ORF, appear to be 3'-coterminal. In contrast to HSV1 mutants with lesions in the UL24 ORF, a BHV1 deletion mutant which failed to produce detectable levels of the 5.2-kb transcript grew nearly as well as wild-type virus.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8128626&dopt=Abstract herpes medicine



herpes
Varicella-zoster virus open reading frame 4 encodes a transcriptional activator that is functionally distinct from that of herpes simplex virus homology ICP27.

Perera LP, Kaushal S, Kinchington PR, Mosca JD, Hayward GS, Straus SE.

Medical Virology Section, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.

Varicella-zoster virus is the etiological agent of chickenpox and zoster in humans and belongs to the Alphaherpesvirinae subfamily within the family Herpesviridae. Much of the current understanding of gene regulation in alphaherpes viruses has been derived from studies of the prototype herpes simplex virus (HSV). In HSV, two virus-encoded, trans-regulatory proteins, ICP4 and ICP27, are essential for the replicative cycle of the virus. ICP4 is important in modulating HSV genes of all three kinetic classes, whereas the trans-regulatory effects of ICP27 are primarily associated with the expression of late genes. Recent evidence indicates that the trans-regulatory effects of ICP27 involve posttranscriptional processing of target gene transcripts (R. M. Sandri-Golding and G. E. Mendoza, Genes Dev. 6:848-863, 1992). The ICP27 homolog in varicella-zoster virus is a 452-amino-acid polypeptide encoded by the open reading frame 4 (ORF4) gene. Contrary to what is found with ICP27, we show that the ORF4 polypeptide is a transcriptional activator of diverse target promoters and has a critical requirement for the presence of upstream elements within these promoters to mediate its transcriptional effects. Evidence is also presented to implicate a critical role for the cysteine-rich, C-terminal region of the ORF4 polypeptide in its trans-regulatory functions. Specifically, by oligonucleotide-directed site-specific mutagenesis, we demonstrate that of 10 cysteine residues in the ORF4 polypeptide, only C-421 and C-426 are essential for transactivator function and suggest that these cysteine residues may participate in critical protein-protein interactions rather than protein-nucleic acid interactions to mediate ORF4 inducibility.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8139031&dopt=Abstract herpes medicine



herpes
Quantity of latency-associated transcript produced by herpes simplex virus is not predictive of the frequency of experimental recurrent genital herpes.

Bourne N, Stanberry LR, Connelly BL, Kurawadwala J, Straus SE, Krause PR.

Division of Infectious Diseases, Children's Hospital Research Foundation, Cincinnati, OH 45229-3039.

The role of the latency-associated transcript (LAT) in control of recurrent herpes simplex virus type 2 (HSV-2) infection was investigated by examining whether LAT concentration in vitro during productive infection or in ganglia during latency correlated with frequency of recurrent genital herpes. Clinical HSV-2 isolates from frequent or infrequent recurrent genital disease produced comparable amounts of glycoprotein D and infected cell polypeptide 0 RNA, but the isolate from frequent disease produced about seven times more LAT. The guinea pig model of genital herpes was used to determine whether the quantity of LAT produced during acute infection in vitro correlated with recurrence phenotype; the frequency of recurrent disease was similar for the 2 clinical isolates. Likewise, there was no correlation between the recurrence phenotype of individual animals and LAT concentration in their ganglia. Thus, while absence of LAT may impair HSV reactivation and recurrence, once a threshold concentration is exceeded, LAT has no further effect on recurrence frequency.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8169396&dopt=Abstract herpes medicine



herpes
The phospholipid composition of extracellular herpes simplex virions differs from that of host cell nuclei.

van Genderen IL, Brandimarti R, Torrisi MR, Campadelli G, van Meer G.

Department of Cell Biology, Medical School AZU H02.314, University of Utrecht, The Netherlands.

Enveloped viruses of eukaryotes obtain their membrane by budding through a cellular membrane. Therefore, most frequently the lipid composition of the virion envelope reflects that of the membrane where budding took place. In the case of herpes simplex viruses, nucleocapsids assemble in the nucleus and bud through the inner nuclear membrane. The pathway from the perinuclear space to the extracellular medium is as yet poorly understood. Here we demonstrate that the phospholipid composition of extracellular herpes simplex virions differs from that of nuclei isolated from the infected cells. The viral membrane contains threefold higher concentrations of sphingomyelin and phosphatidylserine. These lipids are typically enriched in the Golgi apparatus and plasma membrane. The data are in agreement with a model in which herpes simplex virus, after budding through the inner nuclear membrane, loses its envelope by fusing with the outer nuclear membrane and obtains a new membrane by budding into a compartment late in the exocytotic pathway, very likely the Golgi apparatus or membranes derived from it. Alternatively, because the perinuclear space is continuous with the ER lumen, the virus after its first budding may be transported through the exocytotic pathway without ever leaving the lumen of the subsequent compartments. In that case, either the virions, while budding through the nuclear membrane select for sphingomyelin and phosphatidylserine, or the original lipids of the viral envelope are exchanged for lipids of an exocytotic membrane, most likely by a transient membrane continuity between the virion and the vesicle by which it is surrounded. Light particles, virus-like particles that lack capsid and DNA but contain tegument and envelope proteins, displayed the same lipid composition as complete herpes simplex virions, suggesting that they also acquired their envelope from a Golgi membrane.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8178468&dopt=Abstract herpes medicine



herpes
Antiviral therapy after penetrating keratoplasty for herpes simplex keratitis.

Moyes AL, Sugar A, Musch DC, Barnes RD.

W. K. Kellogg Eye Center, Department of Ophthalmology, Ann Arbor.

OBJECTIVE: To assess the efficacy of prophylactic topical antiviral therapy after penetrating keratoplasty for herpes simplex keratitis in the postoperative period and during the treatment of allograft rejection episodes with topical steroids. We used these data to make predictions of the sample size required to perform a prospective study of prophylactic oral acyclovir in the postoperative period. DESIGN: Retrospective review. SETTING: A university referral cornea service. PATIENTS: One hundred thirty-two consecutive penetrating keratoplasties for herpes simplex keratitis in 119 eyes of 118 patients. Only four grafts were performed in actively inflamed eyes. INTERVENTIONS: Sixty-six (52%) of the grafts performed in quiescent eyes received prophylactic postoperative topical antiviral treatment, three (2%) received oral acyclovir, and 59 (46%) received no antiviral therapy. The mean (+/- SD) duration of antiviral therapy was 12.8 +/- 22.5 months. MAIN OUTCOME MEASURES: Herpetic recurrence, allograft rejection episodes, and graft failure. RESULTS: Multivariate analysis showed that early antiviral use was associated with a decreased risk of herpes simplex keratitis recurrence (relative risk [RR] = 0.44; 95% confidence interval [CI], 0.21 to 0.94; P = .007) and allograft rejection (RR = 0.43; 95% CI, 0.25 to 0.75; P = .002). Graft failure was associated with herpetic recurrence within the first year (RR = 2.25; 95% CI, 1.09 to 4.64; P = .001) and allograft rejection episodes (RR = 2.56; 95% CI, 1.20 to 5.26; P = .003). Using these data, a prospective trial of postoperative oral acyclovir would require between 59 and 112 patients per group. CONCLUSIONS: Postoperative prophylactic antiviral treatment is associated with decreased rates of herpes simplex viral keratitis recurrence and allograft rejection. Early recurrence is associated with an increased risk of graft failure. A prospective study of postoperative oral acyclovir would require a multicentered approach.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8185515&dopt=Abstract herpes medicine



herpes
UL69 of human cytomegalovirus, an open reading frame with homology to ICP27 of herpes simplex virus, encodes a transactivator of gene expression.

Winkler M, Rice SA, Stamminger T.

Institut fur Klinische und Molekulare Virologie, Universitat Erlangen-Nurnberg, Germany.

The UL69 open reading frame of human cytomegalovirus (HCMV) is homologous to the immediate-early protein ICP27 of herpes simplex virus, an essential viral regulatory protein involved in the transition from early to late gene expression. Genes with homology to ICP27 have been detected in all subclasses of herpes viruses so far. While the respective proteins in alpha- and gammaherpes viruses have been defined as trans-regulatory molecules, nothing is known about these genes in betaherpes viruses. This study was therefore undertaken in order to investigate expression from the UL69 gene locus of HCMV. Northern (RNA) blot experiments revealed a complex pattern of transcripts that changed during the time course of the HCMV replicative cycle: two transcripts of 2.7 and 3.5 kb that were regulated differentially could be detected as early as 7 h after infection. However, these transcripts could not be detected in the presence of cycloheximide. Additional, larger transcripts were present exclusively at late times after infection. To analyze protein expression from the UL69 gene region, the UL69 open reading frame was expressed as a histidine-tagged protein in Escherichia coli. A specific antiserum was generated and used to detect the UL69 protein in HCMV-infected cells which revealed its localization within the intranuclear inclusions that are characteristic for HCMV infection. In cotransfection experiments, an HCMV true late promoter could not be activated by UL69, whereas an early promoter and several heterologous promoters were stimulated about 10-fold. Complementation studies showed that the UL69 protein cannot substitute for ICP27 in the context of the HSV infection, suggesting functional differences between these two proteins. In summary, these experiments define a novel regulatory protein encoded by HCMV that is expressed as an early-late gene and appears to exert a broad stimulatory effect on gene expression.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8189530&dopt=Abstract herpes medicine