The interplay of T cell responses to viral and autoimmune epitopes

The examination of the immune T cell response to herpes simplex virus (HSV) antigen glycoprotein D (gD) in an ongoing infection has revealed a uniquely broad range of antigenic determinants seen. This has been shown in the murine T cell response to gD determinants where over 60% of the overlapping peptides are recognized as opposed to 1 of 30 peptides seen when gD was injected in Freund’s adjuvant. This has also been seen in the response to local autoantigens when the HSV infection is produced by corneal scarification. Furthermore, analysis of the response to the autoantigen, Golli myelin basic protein (MBP), present in the developing thymus is explored.     

Functional activity of peritoneal macrophages from sensitive and resistant mouse strains during intravaginal infection with herpes simplex virus type 2 and mucosal vaccination

In the early period after intravaginal infection with herpes simplex virus type 2 (2 h), macrophages from sensitive DBA/2 mice were characterized by higher capacity to engulf the antigen, decreased function of the lysosomal apparatus, lower activity of cathepsin D, and reduced oxygen metabolism compared to cells from resistant BALB/c mice. Mucosal vaccination with herpes vaccine and hyaluronic acid promoted the increase in functional activity of macrophages and improved survival of sensitive mice (by 60%). __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 2, pp. 196–200, February, 2008     

Herpes simplex virus type 1 DNA is located within Alzheimer's disease amyloid plaques

The brains of Alzheimer's disease sufferers are characterized by amyloid plaques and neurofibrillary tangles. However, the cause(s) of these features and those of the disease are unknown, in sporadic cases. We previously showed that herpes simplex virus type 1 is a strong risk factor for Alzheimer's disease when in the brains of possessors of the type 4 allele of the apolipoprotein E gene (APOE-epsilon4), and that beta-amyloid, the main component of plaques, accumulates in herpes simplex virus type 1-infected cell cultures and mouse brain. The present study aimed to elucidate the relationship of the virus to plaques by determining their proximity in human brain sections. We used in situ polymerase chain reaction to detect herpes simplex virus type 1 DNA, and immunohistochemistry or thioflavin S staining to detect amyloid plaques. We discovered a striking localization of herpes simplex virus type 1 DNA within plaques: in Alzheimer's disease brains, 90% of the plaques contained the viral DNA and 72% of the DNA was associated with plaques; in aged normal brains, which contain amyloid plaques at a lower frequency, 80% of plaques contained herpes simplex virus type 1 DNA but only 24% of the viral DNA was plaque-associated (p < 0.001). We suggest that this is because in aged normal individuals, there is a lesser production and/or greater removal of beta-amyloid (Abeta), so that less of the viral DNA is seen to be associated with Abeta in the brain. Our present data, together with our finding of Abeta accumulation in herpes simplex virus type 1-infected cells and mouse brain, suggest that this virus is a major cause of amyloid plaques and hence probably a significant aetiological factor in Alzheimer's disease. They point to the usage of antiviral agents to treat the disease and possibly of vaccination to prevent it.     

Malpighian epithelia infected by DNA viruses and Langerhans cells

Malpighian epithelia exhibit an immune surveillance through Langerhans cells (LC) against the DNA viruses, which induce various epithelial lesions, mainly on the skin, conjunctiva, mouth, uterine cervix. These viral infections are usual during childhood. The most common DNA viruses are: adenoviruses (more than 40 types), human papillomaviruses (HPV, more than 50 types) and Herpes viruses (herpes simplex type 1 and 2, varicella and Zooster, Epstein-Barr virus). Different clinical aspects are observed (exanthema, erythema, eruption, papillomas, vesicle, bullous) are well as histological signs. All of these viruses are replicating in the nuclei of epithelial cells which show eosinophilic inclusions and finally cell degeneresence with a typical aspect for each virus such as koilocyte for HPV infection. These lesions are commonly infiltrated with T lymphocytes; the intensity of the local cellular immune response varies with the lesion. LC are reduced in infected epithelia; they are sometimes found in conjunctive tissues and their morphology can be altered; their role in antigen presentation to T lymphocytes has only been demonstrated in herpes simplex virus infections. Profound modifications of membrane antigens of epithelial cells (loss of HLA class 1 antigen) might contribute to the disappearance of LC or to their functional inability. Most of the DNA virus infections are inapparent, benign and transient. However some lesions can evolve towards malignancy; this progression depends on the oncogenic potential of the viruses (such as HPV types 16 and 18 or herpes simplex virus type 2) associated to a local or a general immune deficiency of the patient as well as to other exogenous factors (UV for example).     

T cell response to viral antigens in adults and children with common variable immunodeficiency and specific antibody deficiency

Several T cell abnormalities have been described in common variable immunodeficiency (CVID), a B cell disorder of mainly unknown origin. A subset of CVID patients suffers from frequent reactivations of herpes viruses. We studied T cell function in CVID [and in a subset of paediatric patients with specific antibody deficiency (SAD)] by measuring T cell proliferation and cytokine production in response to herpes virus‐antigens in paediatric CVID patients (n = 9) and paediatric SAD patients (n = 5), in adult CVID patients (n = 14) and in healthy controls. Paediatric CVID patients, but not SAD patients, displayed moderately increased CD8⁺ T cell proliferation in response to cytomegalovirus, human herpes virus type 6B (HHV6‐B) and herpes simplex virus compared to controls. CD8⁺ T cell responses in adult CVID patients tended to be increased in response to cytomegalovirus and herpes simplex virus. In response to stimulation with herpes virus antigens, the proinflammatory cytokines interleukin (IL)‐1β, IL‐6, tumour necrosis factor (TNF)‐α and interferon inducible protein (IP)‐10 were produced. Overall, no major differences were detected in cytokine production upon stimulation between patients and controls, although higher IL‐10 and IL‐12 production was detected in paediatric patients. In conclusion, cellular immunity against herpes virus antigens appears undisturbed in CVID patients, although defects in subpopulations of CVID patients cannot be excluded.     

Consequences of CXCL10 and IL-6 induction by the murine IFN-α1 transgene in ocular herpes simplex virus type 1 infection

Herpes simplex virus type 1 infection of the mouse eye results in an impressive inflammatory response culminating in the death of the animal or the establishment of a “latent” infection depending on a number of ill-defined variables that include components of the innate and adaptive immune system. The application of type I interferon transgenes has been found to antagonize viral replication and spread from the eye to the nervous system. Associated with the in situ transfection of the cornea is the upregulation of two inflammatory molecules, interleukin-6 and CXCL10. In this article, we will further examine the contribution these molecules may have in the host response to ocular infection with herpes simplex virus type 1.     

Combined antiherpetic effect of complex preparation “Viferon® — eye drops” and modified nucleosides

Ready dosage form (eye drops) prepared on the basis of recombinant α₂-IFN exhibits high activity towards herpes simplex type 1 virus in vitro. Systematic study of the antiherpesvirus effect of this drug in combination with modified nucleosides showed an inhibitory effect of the synergic type. Combination of IFN preparation with some nucleosides, including ribavirin, proved to be highly effective towards drug-resistant herpes virus. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 141, No. 6, pp. 672–675, June, 2006     

Trichostatin-A enhances adaptive immune responses to DNA vaccination.

BACKGROUND: The efficacy of DNA vaccines to date has overall been disappointing, especially in large animal models and in humans, which might be partially explained by the chromatinization of the administered foreign DNA. Trichostatin-A (TSA) is a specific inhibitor for histone deacetylase (HDAC) and a gene expression enhancer in in vitro DNA viral infection, including herpes simplex type 1 (HSV-1) and cytomegalovirus (CMV). OBJECTIVES: We sought to determine if increasing antigen expression of DNA vaccines through inhibition of HDAC-induced chromatin silencing using TSA would enhance DNA vaccine efficacy in vivo. STUDY DESIGN: A luciferase assay was used to detect effects of TSA on different promoters in vitro. The effects of TSA on DNA vaccination of mice were determined by neutralization assays for antibody production and interleukin staining for detection of specific T cell responses. RESULTS: Mice receiving TSA in combination with a DNA vaccine exhibited higher antibody responses to the vaccine than mice not given TSA. Co-administration of TSA also enhanced specific CD8 T cells response. CONCLUSION: Drugs such as TSA that reduce initial gene silencing by preventing histone deacetylation can increase immune responses to DNA vaccination.     

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.     

Recovery of mice from herpes simplex virus type 2 hepatitis: adoptive transfer of recovery with immune spleen cells.

Young BALB/c mice inoculated intraperitoneally with herpes simplex virus type 2 develop focal necrotizing hepatitis. After infection, the livers of these mice show increasing virus titers, which reach a maximum on day 3 after infection; this is followed by a dramatic decrease in the amount of virus recovered on days 4 and 5. This decrease in virus content is accompanied by a progressive infiltration of the lesions with mononuclear leukocytes and an apparent resolution of the lesions. Adoptive transfer of immune spleen cells from mice infected 6 days earlier accelerated this process. When 50 x 10(6) to 100 x 10(6) immune spleen cells were transferred 24 h after infection, the inflammatory response and the clearance of virus from the livers were advanced by almost 2 days. As few as 12 x 10(6) immune spleen cells accelerated the healing process, whereas fewer immune cells, disrupted immune cells, or normal spleen cells did not have an effect. The protection conferred by herpes simplex virus type 2-sensitized immune spleen cells was specific since mouse cytomegalovirus- or vaccinia virus-sensitized immune spleen cells had no effect on the course of infection with herpes simplex virus type 2, whereas some cross-reactivity was observed between herpes simplex virus types 1 and 2. This model seems to be suitable for examining the immunological mechanisms that are active during recovery from visceral herpes simplex virus infections.     

Lymphocyte transformation and interferon production in human mononuclear cell microcultures for assay of cellular immunity to herpes simplex virus.

Interferon production and transformation in response to herpes simplex virus antigen were studied in microcultures of human mononuclear cells. Mononuclear cells consisting of monocytes and both T and B lymphocytes were purified by Ficoll-Hypaque gradients. Lymphocytes, predominantly T with 5% B, were obtained by passage of buffy-coat cells through nylon fiber columns. For some experiments, autochthonous macrophages and column-purified lymphocytes were stimulated with herpesvirus antigen. The effect of specific antibody and cell concentration on reactivity is described. Crude and purified antigens were compared as cell culture stimulants. Significant differences in transformation and interferon were observed between donors with a history of herpes labialis and donors with no detectable antibody, both in cultures prepared by Ficoll-Hypaque gradients and by column purification of lymphocytes. Cultures from seronegative donors prepared by Ficoll-Hypaque gradients produced interferon but did not transform when stimulated by herpes simplex antigen. "Immune" interferon production, that is, type II as opposed to type I, occurred only with autochthonous macrophage and column-purified lymphocyte cultures. Interferon produced by Ficoll-Hypaque-purified mononuclear cultures was type I, and its production was unrelated to immune status. Similarly, column-purified lymphocytes responded to herpes simplex virus antigen with type I interferon if obtained from a seropositive donor.     

Current developments in viral DNA vaccines: shall they solve the unsolved?

This review describes the mechanisms of immune response following DNA vaccination. The efficacy of DNA vaccines in animal models is highlighted, especially in viral diseases against which no widely accepted vaccination is currently available. Emphasis is given to possible therapeutic vaccination in chronic infections due to persisting virus genomes, such as recurrent herpes (HSV-1 and HSV-2), pre-AIDS (HIV-1) and/or chronic hepatitis B (HBV). In these, the problem of introducing foreign viral DNA may not be of crucial importance, since the immunised subject is already a viral DNA (or provirus) carrier. The DNA-based immunisation strategies may overcome several problems of classical viral vaccines. Novel DNA vaccines could induce immunity against multiple viral epitopes including the conservative type common ones, which do not undergo antigenic drifts. Within the immunised host, they mimic the effect of live attenuated viral vaccines when continuously expressing the polypeptide in question. For this reason they directly stimulate the antigen-presenting cells, especially dendritic cells. The antigen encoded by plasmid elicits T helper cell activity (Th1 and Th2 type responses), primes the cytotoxic T cell memory and may induce a satisfactory humoral response. The efficacy of DNA vaccines can be improved by adding plasmids encoding immunomodulatory cytokines and/or their co-receptors.     

Herpes simplex virus infection of human T-cell subpopulations.

The ability of herpes simplex virus type 1 to productively infect human T-cell subpopulations was examined. Unstimulated helper/inducer (T4+) and cytotoxic/suppressor (T8+) lymphocytes limited herpes simplex virus replication as effectively as unseparated peripheral blood T cells (T3+). Phytohemagglutinin stimulation before infection resulted in equivalently productive herpes simplex virus infections in the three cell fractions.     

Preparation and efficacy of antiherpes type 1 and 2 subunit vaccines

DNA free antiherpes subunit vaccines were prepared from diploid human embryonic lung cells infected either with type 1 or type 2 herpes simplex viruses (HSV). Virion and membrane-bound virus-specific glycoproteins were solubilized with Nonidet P-40 and separated by ultracentrifugation. The antigenic properties of the vaccine were tested in guinea pigs. Antibody response was followed by virus neutralization and complement fixation. The vaccine itself was low-immunogenic, however its immunogenicity has considerably increased by usage of suitable adjuvants. In virus neutralization test higher antibody titre was found against homologous virus. The antibody response was related to protein content and to the frequency of vaccination.     

Detection of type 2 herpes simplex virus in cells of spermatogenic epithelium in infected testes of guinea pigs

We developed a model of herpetic orchitis in guinea pigs. Intratesticular inoculation of type 2 herpes simplex virus suspension results in infection of the testicular spermatocytes and spermatides. The possibility of viral infection dissemination from infected into intact testis is proven. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 7, pp. 79–83, July, 2007     

DNA polymerase in pseudorabies virus infected cells.

The DNA polymerase activity in BHK 21/C13 cells infected with pseudorabies virus is inhibited by incubation with antiserum to pseudorabies but not by incubation with pre-immune serum or by antiserum to herpes simplex virus type 1 (HSV-1) or herpes simplex virus type 2 (HSV-2). It also differs from the cell enzyme and the enzymes in HSV-1 or HSV-2 infected cells in its requirement for KCl in the in vitro assay. It seems likely, therefore, that pseudorabies virus specifies its own DNA polymerase.     

Synergic antiherpetic effect of para-aminobenzoic acid and modified nucleosides

New results of combined therapy of herpetic infection in Vero cells infected with herpes simplex type I virus resistant to acyclovir (acycloguanosine, Zovirax) are presented. Paraaminobenzoic acid stimulates antiherpetic effects of acycloguanosine, 5-(2-bromovinyl)-2′-deoxyuridine and adenine 9-β-d-arabinofuranoside. para-aminobenzoic acid alone is incapable of suppressing type I herpes simplex virus reproduction in cell culture. Modified nucleosides combined with it exert a higher selective antiherpetic effect. Para-aminobenzoic acid is capable of inactivating herpes viruses in culture medium. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 8, pp. 188–191, August, 1997     

Pathogenetic aspects of severe course of herpetic infection

We studied the state of antiviral defense in patients with severe course of herpetic infection of anogenital and labial localization and the frequency of its combination with other herpes virus infections. It was found that severe course of herpetic infection caused by herpes simplex virus occurs against the background of combined secondary immunodeficiency and its complication. We first demonstrated that severe course of the disease is associated with mixed viral infection. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Supplement 2, pp. 76–81, April, 2007     

Systemic T cell expansion during localized viral infection

In a local immune response, the priming and expansion of the antigen-specific T cell population has been thought to largely take place in the draining lymphoid tissue. This model was primarily based on indirect enumeration of antigen-specific T cells by limiting dilution analyses. Here, tetrameric MHC class I complexes were used to evaluate the contribution of different secondary lymphoid organs in a local immune response by following the CD8+ T cell responses against the immunodominant epitopes of influenza A virus and herpes simplex virus-1. Mice were either intranasally infected with influenza A virus and developed pneumonia or were intradermally injected with herpes simplex virus-1. Remarkably, even though these viruses cause a local infection, the spleen of infected animals contains approximately 50-fold more antigen-specific cytotoxic T cells than the draining lymph nodes. Although antigen-specific T cells in spleen appear not to have experienced any recent encounter with antigen, this population is actively dividing, and over time, the formation of a memory T cell population is observed. These data reveal that there is a remarkably large and distinct population of antigen-specific T cells in spleen in the course of a local antigenic challenge. This T cell compartment may not only form the foundation of a memory T cell pool but could also provide a safeguard against systemic spreading of an infection.     

Characterization of immunogenic properties of polyclonal T cell vaccine intended for the treatment of rheumatoid arthritis

Two-staged technology for obtaining polyclonal T cell vaccine intended for the treatment of rheumatoid arthritis is described. Stage 1 includes antigen-dependent cultural selection of patient’s T cells and stage 2 consists in their reproduction in the needed amounts by nonspecific mitogenic stimulation. T cell vaccination induces an effective specific anti-idiotypic immune response against T cells reactive to joint antigens. Vaccine therapy significantly reduces plasma level of IFN-γ and increases IL-4 level. The results indicate immunological efficiency and safety of polyclonal T cell vaccine in patients with rheumatoid arthritis. __________ Translated from Kletochnye Tehnologii v Biologii i Medicine, No. 4, pp. 221–225, October, 2007