Homing in on the Cellular Immune Response to HSV-2 in Humans*.

Koelle DM, Gonzalez JC, Johnson AS. Homing in on the cellular immune response to HSV-2 in humans. AJRI 2005; 53:172-181 (c) Blackwell Munksgaard, 2005Problem: Genital herpes simplex infections are generally limited to epithelia and neurons. Vaccines have had activity in herpes simplex virus (HSV)-seronegative women only. Understanding how HSV-specific T cells traffic to infected sites may assist in vaccine design. Method of Study: Herpes Simplex virus epitopes recognized by HSV-specific CD8 T cells were identified and used to make fluorescent human leukocyte antigen (HLA)-peptide tetramers. Molecules related to lymphocyte rolling adhesion were studied by flow cytometry and cell binding. HSV-specific CD4 T cells identified ex vivo by cytokine accumulation or activation marker expression, or detected in vitro by 5-(and-6)-carboxyfluorescein diacetate, succinimidyl ester (CFSE) dilution, were similarly investigated. Results: Herpes Simplex virus-specific T cells are 10- to 100-fold more prevalent in lesional skin compared with blood and greatly enriched in lesions compared with normal skin. Diverse viral antigens are recognized by HSV-specific T cells. Functionally active E-selectin ligand, and cutaneous lymphocyte antigen (CLA), are expressed by circulating HSV-2-specific CD8 cells. CD4 cells display lower levels of CLA that are dramatically up-regulated upon re-stimulation with antigen. Conclusions: Herpes Simplex virus-2-specific CD8 and CD4 T cells differ in constitutive expression of skin homing molecules. Vaccines designed to induce proper homing are postulated to have increased efficacy.

Clinical management of Genital Herpes: what can be done in pregnancy?

Neonatal herpes simplex infection is the major complication of genital herpes simplex even if it occurs in less than 1/10,000 births. A great number of recent studies illustrates the natural history of Genital Herpes. The importance of viral transmission by asymptomatic shedding is now well established. The widespread use of viral diagnosis strategies is the prerequisite to efficient genital herpes simplex prevention in order to eradicate viral mother-to-child transmission. This starts with the detection of at-risk situations such as primary infection in late pregnancy. Once the at-risk situation is known there should be concern about the adaptation of treatment strategies including antiviral therapy. The following work proposes different strategies facing each at-risk situation in order to discuss the efficiency of new diagnostic and treatment tools.

Enhanced atherogenesis is not an obligatory response to systemic herpes simplex virus infection in the apoE-deficient mouse: comparison of murine gamma-herpes virus-68 and herpes simplex virus-1.

Viral and bacterial infectious agents have been implicated in the etiology of atherosclerosis. We have previously shown that a gamma-herpes virus can accelerate atherosclerosis in the apolipoprotein E-deficient (apoE-/-) mouse. To address whether a virally induced systemic immune response is sufficient to trigger enhanced atheroma formation, we infected apoE-/- mice with murine gamma-herpes virus-68 (MHV-68) or herpes simplex virus-1 (HSV-1). In this study, we show that both viruses were able to induce a cell-mediated and humoral immune response in the apoE-/- mouse, which was sustained over a period of 24 weeks. Although intranasal or intraperitoneal infection with MHV-68 induced similar levels of virus-specific IgG1 and IgG2a antibodies in the serum of apoE-/- mice, those infected with HSV-1 showed higher anti-HSV-1 IgG2a compared with IgG1 antibody levels. In addition, viral message was not detected in the aortas of HSV-1-infected animals, whereas we have shown previously that MHV-68 mRNA can be detected in the aortas of infected mice as early as 5 days after infection. Compared with control mice, apoE-/- mice infected with MHV-68 showed accelerated atherosclerosis, whereas mice infected with HSV-1 did not. These data indicate that a systemic immune response to any particular infectious agent is insufficient to induce enhanced atherosclerosis in the apoE-/- mouse and point to specific infections or immune mechanisms that might be essential for virally enhanced atherogenesis.

Mutations within conserved motifs in the 3'-5' exonuclease domain of herpes simplex virus DNA polymerase.

We investigated mutations within the presumed 3'-5' exonuclease domain of the DNA polymerase from herpes simplex virus type 1. The mutation sites correspond to residues in DNA polymerase I (Escherichia coli) which bind two metal ions that are required for exonuclease function. To evaluate the effect of the herpes simplex virus mutations on enzymatic activity, we overexpressed the wild-type DNA polymerase and one mutant enzyme using a baculovirus expression system. Both proteins exhibited DNA polymerase activity after partial purification, but the mutant protein was drastically deficient in exonuclease activity. This finding suggests that the herpes simplex virus exonuclease may utilize the same metal-ion-mediated mechanism employed by DNA polymerase I. We also attempted to transfer each of the mutations into the herpes simplex virus genome using a marker rescue protocol. Although wild-type sequences could be transferred readily, recombinant viruses carrying mutant sequences were not recovered. We discuss the possibility that the mutations are lethal and suggest mechanisms by which a deficiency in 3'-5' exonuclease might cause loss of viability.

The BamHI fragment 9 of pseudorabies virus contains genes homologous to the UL24, UL25, UL26, and UL 26.5 genes of herpes simplex virus type 1.

The genomes of pseudorabies virus (PrV) and of herpes simplex virus type 1 (HSV1) are colinear, excepting an inversion in the unique long region, of which one extremity resides within the BamHI fragment 9. This fragment (4088 bp) encodes the counterparts of HSV1 UL24, UL25, UL26 and UL26.5 that are transcribed into four 3'-coterminal mRNAs. Multiple alignments of UL24, UL25 and UL26 protein homologs from alpha-, beta- and gamma-herpes viruses were performed. The PrV UL24 protein is shorter than its counterparts, missing the non-conserved COOH-terminal region. The region which is common to all viruses contains a basic NH2-terminus and a hydrophobic COOH-end, suggesting that UL24 may function as a matrix protein. The UL25 proteins are well conserved, particularly among the alpha-herpes viruses. All the domains involved in the proteolytic activity of theUL26 protein are highly conserved, as well as the two cleavage sites. Thus, its function and processing may be similar in PrV as in other herpes simplex viruses. Due to the fact that in PrV the UL26 and UL44 genes are adjacent and their ends are conserved, the right border of the inversion must lie within their intergenic region.

Development of a polymerase chain reaction and restriction typing assay for the diagnosis of bovine herpes simplex virus 1, bovine herpes simplex virus 2, and bovine herpes simplex virus 4 infections.

A multiplex polymerase chain reaction (PCR) method coupled with a restriction analysis of PCR products (PCR with restriction fragment length polymorphism) was developed for the simultaneous detection of bovine herpes simplex virus 1, bovine herpes simplex virus 2, and bovine herpes simplex virus 4 infections. The specificity, sensitivity, and practical diagnostic applicability of this method were evaluated. This assay may be also adapted to the diagnosis of suid herpes simplex virus 1 and equine herpes simplex viruses 1 and 3 and could become a powerful diagnostic tool.

Otarine herpes simplex virus-1: a novel gammaherpes virus associated with urogenital carcinoma in California sea lions (Zalophus californianus).

The incidence of neoplasia in California sea lions (CSLs) is considered to be unusually high. Electron microscopic examination of some of these urogenital tumours revealed the presence of virions with typical herpes-like structure. While current attempts to cultivate this virus have not been successful, molecular studies employing DNA extracted from tumour tissues allowed both the classification of the agent and its identification in tumours and archived tissue samples. Two genome fragments generated using degenerate primers in PCR demonstrated highest identities with other mammalian gammaherpes viruses. Phylogenetic analysis showed that this novel virus, tentatively designated Otarine herpes simplex virus-1 (OtHV-1), grouped with members of the gammaherpes virus subfamily and was distinct from PHV-2, a previously described pinniped gammaherpes virus. An OtHV-1 specific PCR was established and used to investigate the presence of this virus in CSL tissues. PCR of DNA isolated from animals with these tumours, demonstrated that this virus was present in 100% (16/16) of tumours. Furthermore, DNA extracted from archived brain and muscle tissues was also positive in 29% (4/14) and 50% (7/14) of cases examined. This preliminary study provides evidence to support the hypothesis that the presence of this novel gammaherpes virus is a factor in the development of urogenital carcinoma in CSLs.

The sequelae of herpes zoster.

BACKGROUND: The last 40 years was a period during which the incidence of herpes zoster appears to have increased substantially. OBJECTIVE: To determine whether the risk of complications of herpes zoster has changed during the last 40 years. METHODS: The automated medical records of a health maintenance organization were screened for diagnosis codes suggesting herpes zoster and potentially complicated cases of zoster. The predictive value of a herpes zoster diagnosis was calculated from sampling full-text records. Records of all patients with codes suggesting complications were reviewed in full. RESULTS: Of 859 individuals with herpes zoster who met the eligibility criteria, 101 were identified who experienced at least 1 complication, corresponding to a 60-day risk of 12%. Corrected for the sensitivity of the complication-finding strategy, the risk estimate was 14%. Risk increased markedly with age, with those older than 64 years having more than 6 times the risk of complications of those younger than 25 years (odds ratio, 8.3; 95% confidence interval, 2.5-29.3). Trigeminal distribution of rash and the presence of certain conditions associated with immune compromise appeared to increase risk. CONCLUSIONS: The apparent increase in the incidence of herpes zoster was not accompanied by a change in the risk of specific or overall complications in a population-based sample. Advanced age and other conditions associated with waning cellular immunity may confer an increased risk of experiencing a complicated course of herpes zoster.

Three-dimensional structure of the human herpes simplex virus 8 capsid.

Human herpes simplex virus 8 (HHV-8), or Kaposi's sarcoma-associated herpes simplex virus, is a gammaherpes virus implicated in all forms of Kaposi's sarcoma and certain lymphomas. HHV-8 has been extensively characterized, both biochemically and immunologically, since its first description in 1994. However, its three-dimensional (3D) structure remained heretofore undetermined largely due to difficulties in viral purification. We have used log-phase cultures of body cavity-based lymphoma 1 cells induced with 12-O-tetradecanoylphorbol-13-acetate to obtain HHV-8 capsids for electron cryomicroscopy and computer reconstruction. The 3D structure of the HHV-8 capsids revealed a capsid shell composed of 12 pentons, 150 hexons, and 320 triplexes arranged on a T=16 icosahedral lattice. This structure is similar to those of herpes simplex virus type 1 (HSV-1) and human cytomegalovirus (HCMV), which are prototypical members of alpha- and betaherpes viruses, respectively. The inner radius of the HHV-8 capsid is identical to that of the HSV-1 capsid but is smaller than that of the HCMV capsid, which is consistent with the relative sizes of the genomes they enclose. While the HHV-8 capsid exhibits many structural similarities to the HSV-1 capsid, our reconstruction shows two major differences: its hexons lack the "horn-shaped" VP26 densities bound to the HSV-1 hexon subunits, and the HHV-8 triplexes appear smaller and less elongated than those of HSV-1. These differences are in excellent agreement with our sequence comparisons of HHV-8 and HSV-1 capsid proteins. This gammaherpes virus capsid structure complements previous structural studies on alpha- and betaherpes viruses in providing an account of structural similarities and differences among capsids representing all human herpes simplex virus subfamilies.

A role for a new herpes simplex virus (KSHV) in different forms of Kaposi's sarcoma.

PIP: Samples were examined by polymerase chain reaction (PCR) for the presence of the putative Kaposi's sarcoma herpes simplex virus (KSHV). KS DNA from HIV-negative, African, endemic (EKS) samples, and epidemic HIV-positive KS (AKS), and sporadic KS (SKS) samples were tested from Tanzania and Sweden. All of the HIV KS (18 African EKS and 4 Swedish SKS) as well as the HIV-positive AIDS-related KS (16 African and 7 Swedish AKS) biopsies were shown to contain the previously described DNA sequences. KS lesions from children, females, and males in various tissues were analyzed including skin, lymph nodes, gut and oral mucosa. All forms of KS showed a single PCR product of the expected size (233 base pairs). To exclude amplification of other types of herpes simplex virus, virus preparations of Epstein-Barr virus (EBV), herpes simplex virus, cytomegalovirus, vesicular stomatitis, and human herpes simplex virus type 6 (HHV6) were assayed, again by PCR, using the KSHV primers. No PCR products were obtained with any of these virus strains. However, most HIV-positive and HIV-negative KS DNA samples also contained either EBV and/or HHV6 sequences. All biopsies from non-KS tissues (cells) of HIV-positive and HIV-negative individuals were consistently negative for KSHV by PCR. The observation that the same herpes simplex virus-like DNA sequence is present in endemic and sporadic, as well as AIDS-related, Kaposi's sarcoma cases suggests a possible pathogenic association between this putative novel, herpes-like virus and KS. The herpes simplex virus-like DNA sequences described by Y. Chang in 1994 may indeed represent a novel herpes simplex (KSHV), etiopathologically associated with various clinical forms of Kaposi's sarcoma. Its pathogenic importance is indicated by its presence in different KS tissues with various clinical types of KS and its absence from non-KS-involved tissues. Furthermore, the presence of KSHV in KS of children suggests a nonsexual mode of transmission.