Herpesvirus Infections In Mice Research Articles

Virally-Induced Upregulation of Heparan Sulfate on B Cells via the Action of Type I IFN

Cell surface heparan sulfate (HS) is an important coreceptor for many cytokines, chemokines, and growth factors. In this study, we report that splenic murine B cells express very little HS and that upon infection with either gammaherpesvirus (murine gammaherpesvirus 68) or betaherpesvirus (murine cytomegalovirus), HS is rapidly upregulated at the surface of B cells. HS upregulation was not observed in mice deficient for the type I IFN (IFN-I) receptor. Additionally, treatment of wild-type mice with the IFN-I inducer polyinosine polycytidylic acid triggered HS expression at the B cell surface. Similarly, incubation of purified splenic B cells with IFN-I, TLR ligands, or BCR stimulators ex vivo resulted in a drastic increase in HS surface expression. We found that IFN-I induced an increase in the surface expression of HS-modified syndecan 4 as well as that of an unidentified heparan sulfate proteoglycan. Finally, IFN-I treatment increased B cell responsiveness to APRIL, a cytokine involved in B cell survival and T cell-independent B cell responses. Enzymatic removal of HS from IFN-I-treated B cells inhibited APRIL. Altogether, our results indicate that upon herpesvirus infection in mice, HS is rapidly upregulated at the surface of B cells due to the action of IFN-I, potentially increasing B cell responsiveness to cytokines. Induction of HS expression at the B cell surface by stimulators of the innate immune response likely plays a key role in the development of a robust immune response.

Modeling of Chronic Herpesvirus Infection. Experimental Studies of Infectious Process in Mice

The dynamics of infectious process was studied by modeling chronic herpesvirus infection in mice. The infectious process ran a wave-like course with periods of relapses and remissions. Clinical manifestations and severity and duration of relapses largely depended on the disease duration. Reactivation of herpesvirus led to systemic involvement, this indicating the dissemination of infection in animals and chronic transformation of the disease.

Cholesterol Paves the Way for Topically Applied Viricides

Sexually transmitted viral infections have the potential to be prevented and treated by topical viricides. Here, Wu et al. (2009) demonstrate that cholesterol-conjugated small interfering RNAs (siRNAs) targeting a cellular receptor combined with an antiviral siRNA when topically applied to mucosal tissue blocked lethal herpes virus infections in mice.

Candidate Microbicide PPCM Blocks Human Immunodeficiency Virus Type 1 Infection in Cell and Tissue Cultures and Prevents Genital Herpes in a Murine Model

A structurally novel candidate microbicide, PPCM, which is formed from the reaction of D,L-mandelic acid with sulfuric acid, provides activity against human immunodeficiency virus (HIV) and herpes simplex virus (HSV) and is not cytotoxic. The objectives of the current studies were to comprehensively evaluate the activity of PPCM in cell and explant cultures, explore the possibility of combining PPCM with HIV-specific reverse transcriptase inhibitors, and evaluate the efficacy of a formulated gel against genital herpes in a murine model. PPCM inhibited infection by laboratory and clinical R5 and X4 clade B and clade C HIV strains in cell culture. Ectocervical and endocervical tissue explants exposed to HIV-1(BaL) in the presence of PPCM were protected (50% inhibitory concentrations [IC(50)] of 3.9 microg/ml for ectocervix and 3.1 microg/ml for endocervix), and transfer of virus to target T cells via migratory cells was significantly impaired (IC(50) of 35.7 microg/ml for ectocervix and 54.6 microg/ml for endocervix). The drug also blocked infection by cell-associated virus. Combinations of PPCM with UC-781 or PMPA in vitro exhibited additive anti-HIV activity. PPCM was incorporated into stable, low-pH gel formulations at concentrations of 0.4% and 4%. Both gels prevented genital herpesvirus infection in mice, even when virus was introduced in human seminal plasma. The abilities of PPCM to inhibit primary HIV isolates, reduce infection by cell-associated virus, and transfer of HIV from migratory to T cells, combined with the complete protection provided by formulated gel against genital herpes, indicate that this drug is an excellent candidate for inclusion in a combination microbicide and would provide protection against both HIV and HSV.

Control of Virus Reactivation Arrests Pulmonary Herpesvirus-induced Fibrosis in IFN-γ Receptor–deficient Mice

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrotic lung disorder of unknown cause. Several studies suggest an association between Epstein-Barr virus pulmonary infection and the development of IPF. To determine whether reduction of gamma-herpesvirus reactivation from latency would alter progressive lung fibrogenesis in an animal model of virus-induced pulmonary fibrosis. IFN-gamma receptor-deficient (IFN-gammaR(-/-)) mice infected intranasally with murine gamma-herpesvirus 68 (MHV68) develop lung fibrosis that progresses for up to at least 180 days after initial infection. Viral replication during the chronic phase of infection was controlled by two methods: the administration of cidofovir, an antiviral drug effective at clearing lytic but not latent virus, and by using a mutant gamma-herpesvirus defective in virus reactivation from latency. Ten percent of the asymptomatic MHV68-infected animals that received antiviral treatment beginning on Day 45 postinfection had severe pulmonary fibrosis compared with 40% of the control saline-treated animals. Absence of severe fibrosis was also observed in IFN-gammaR(-/-) mice infected with the defective reactivation mutant MHV68 v-cyclin stop. Decreased fibrosis was associated with lower levels of transforming growth factor-beta, vascular endothelial growth factor, and markers of macrophage alternative activation. When antiviral treatment was administered on Day 60 in symptomatic animals, survival improved from 20 to 80% compared with untreated symptomatic animals, but lung fibrosis persisted in 60% of the mice. MHV68-induced fibrosis is a result of viral lytic replication during chronic lung herpesvirus infection in mice. We speculate that antiviral therapy might help to control lung fibrosis in humans with IPF and associated herpesvirus infection.

Equine herpesvirus 1 glycoprotein D expressed in E. coli provides partial protection against equine herpesvirus infection in mice and elicits virus-neutralizing antibodies in the horse

The envelope glycoprotein D of EHV-1 (EHV-1 gD) is essential for virus infectivity and entry of virus into cells and is a potent inducer of virus-neutralizing antibody. In this study, truncated EHV-1 gD (gDt) was expressed with a C-terminal hexahistidine tag in E. coli using a pET vector. Western blot analysis using an anti-gD monoclonal antibody demonstrated the presence of gDt bands at 37.5, 36, 29.5 and 28 kDa. The immunogenicity and protective efficacy of partially purified gDt was compared with gD expressed in insect cells by a recombinant baculovirus (Bac gD) using a BALB/c mouse model of EHV-1 respiratory infection. The proteins were also compared in a prime-boost protocol following an initial inoculation with gD DNA. gDt elicited similar levels of gD-specific antibody and neutralizing antibody compared with Bac gD and also provided a similar level of protection against EHV-1 challenge in mice. Inoculation of horses with gDt elicited EHV-1 gD-specific antibodies including virus-neutralizing antibody, suggesting that despite the lack of glycosylation, E. coli may be a useful vehicle for large scale production of EHV-1 gD for vaccine studies.

Effect of Polyanionic Compounds on Intracutaneous and Intravaginal Herpesvirus Infection in Mice

Several polyanionic compounds were found to suppress intracutaneous infection of hairless mice with herpes simplex virus type 2 (HSV-2) only when present at the time of inoculation. Because (a) sexual intercourse is a major route of infection with human immunodeficiency virus (HIV); (b) due to the species-specificity of HIV, there is no small animal model to study intra-vaginal HIV infection; (c) HIV is equally or even more sensitive than HSV-2 to several polyanions; and (d) sulfated polymers may prevent the adhesion of (HIV-infected) lymphocytes to epithelial cells, we evaluated the effect of the compounds on intravaginal infection of mice with HSV-2. To this end, mice were infected intravaginally with a virus-compound mixture. Under the conditions used, the polysulfate dextran sulfate conferred only partial protection against infection and virus-induced mortality. However, PAVAS (a co-polymer of acrylic acid with vinylalcohol sulfate) completely protected against the infection. These results should be taken into account when planning clinical studies with a vaginal polysulfate formulation for the prevention of sexually transmitted HIV and/or HSV-2 infections.

Effect of polyanionic compounds on intracutaneous and intravaginal herpes virus infection in mice: Impact on the search for vaginal microbicides

Effect of polyanionic compounds on intracutaneous and intravaginal herpes virus infection in mice: Impact on the search for vaginal microbicides

Effect of Benzoylmesaconine on Opportunistic Herpesvirus Infections in Mice with Acquired Immunodeficiency Syndrome

Effect of Benzoylmesaconine on Opportunistic Herpesvirus Infections in Mice with Acquired Immunodeficiency Syndrome

Evaluation of SQ 34,514: pharmacokinetics and efficacy in experimental herpesvirus infections in mice.

The new antiviral nucleoside SQ 34,514 [(1R-1 alpha, 2 beta, 3 alpha)-2-amino-9- [2,3-bis(hydroxymethyl)cyclobutyl]-6H-purin-6-one], the active R isomer of racemic SQ 33,054 (cyclobut-G), was evaluated for efficacy in the treatment of herpesvirus infections in mice. SQ 34,514 was orally efficacious in a herpes simplex virus type 1 (HSV-1) systemic infection, an intracerebral HSV-2 infection, a vaginally induced HSV-2 infection in ovariectomized mice, and in a systemic murine cytomegalovirus infection. SQ 34,514 compared favorably with acyclovir and ganciclovir in the treatment of these experimental infections. In mice, SQ 34,514 had an oral bioavailability of 80% based on urinary excretion. SQ 34,514 may have potential value in the therapy of HSV and cytomegalovirus infections in humans.

Effect of antibody to interferon on genital herpesvirus infection in mice

The effect of anti-mouse interferon (IFN) antibody on the course of genital herpes infection was studied in C57BI/6J mice. As we have previously described, intravaginal inoculation of C57 mice with herpes simplex virus type 2 (HSV-2) results in the development of genital lesions, subsequent encephalitis and death, with the mortality rate dependent on virus dose. In the present study, we found that intravaginal application of 1 × 10 5 units of anti-mouse ( α β ) IFN antibody did not significantly affect the course of infection. However, intraperitoneal or intravenous injection (the latter to a lesser extent) of anti-IFN antibody resulted in increased morbidity and mortality. In addition, intraperitoneal injection of anti-IFN antibody decreased the level of detectable endogenous IFN in peripheral blood and at the site of infection. The clear effect of anti-IFN antibody during early stages of infection points to the possible significance of early endogenous IFN production in ameliorating HSV-2 genital infection.

Erythro-9-(2-hydroxy-3-nonyl) Adenine alone and in combination with 9-beta-D-arabinofuranosyladenine in treatment of systemic herpesvirus infections in mice.

Although the antiviral activity of erythro-9-(2-hydroxy-3-nonyl)adenine, a potent adenosine deaminase inhibitor, against herpes simplex virus type 1 in cell culture was readily confirmed, the compound was found to be totally ineffective in the treatment of experimentally induced systemic herpes simplex virus type 1 infections in Swiss mice. Data were obtained, however, which clearly indicated that the antiviral potency of 9-beta-D-arabinofuranosyladenine in vivo could be enhanced by the co-administration of low, nontoxic doses of erythro-9-(2-hydroxy-3-nonyl)adenine.

Preparation and efficacy of an inactivated subunit vaccine (NFUI BHK) against type 2Herpes simplex virus infection

A vaccine against Herpes simplex virus infection was prepared by Nonidet NP 40 and formalin treatment of a type 1, infected-cell extract; virus particles were removed by ultracentrifugation over sucrose. These procedures were not detrimental to the antigenic quality of the vaccine preparation. The vaccine afforded significant protection to experimental type 2 genital herpes virus infection in mice, as adjudged by clinical observations, cytopathological change, and virus yields.

EFFECT OF A NOVEL ADENOSINE DEAMINASE INHIBITOR (CO‐VIDARABINE, CO‐V) UPON THE ANTIVIRAL ACTIVITY IN VITRO AND IN VIVO OF VIDARABINE (VIRA‐ATM) FOR DNA VIRUS REPLICATION

A new potent inhibitor of adenosine deaminase (co-vidarabine) was used in combination studies with adenine arabinoside (vidarabine, Vira-ATM) to protect this purine nucleoside from enzymatic deamination to the more weakly active metabolite, hypoxanthine arabinoside. Comparing the combination to vidarabine alone, a significant increase (10-fold) of the antiviral activity of the combined drugs was observed against herpes and vaccinia viruses in tissue culture and subcutaneously, against cranial herpesvirus infections in mice. Several other investigators have also recently reported several-fold enhancement of vidarabine activity by newly described deaminase inhibitors. They observed that plaque formation by several large DNA-containing viruses (herpes, vaccinia, varicella zoster) and an RNA-containing oncogenic virus was markedly prevented by the combination compared to vidarabine alone. In animals, enhanced protection (increased survivors) and/or highly significant increase in the life span of dying mice treated with the 2-drug combination, was also observed compared to vidarabine administered singly. These observations in animals clearly indicate that combination studies with vidarabine (Vira-ATM) and co-vidarabine (deaminase inhibitor) deserve serious consideration as future therapy for systemic virus infections in man including herpesvirus encephalitis.

Genetics of natural resistance to herpesvirus infections in mice

INHERITED resistance to virus infections has been demonstrated in several murine systems1–6. Susceptibility to mouse hepatitis virus3 and resistance to arbovirus7 infections in mice are dominant traits associated with the capacity of macrophages from the susceptible strains to replicate virus. Resistance to Friend leukaemia virus- and Gross leukaemia virus-induced leukaemogenesis is determined by at least two genes, one closely linked to the immune response genes of the mouse8. Conversely, susceptibility to lymphocytic choriomeningitis (LCM) virus infections in mice has been associated with a gene closely linked to the immune response genes9. The latter seems to be associated with the cell-mediated immune response to LCM which causes tissue damage and leads to death. Cell-mediated immunity seems to be important in resistance against herpes simplex virus (HSV) infections10–12. Analysis of the aspects of cell-mediated immunity which might be involved in resistance in man is complicated by the uncontrollable factors associated with activation of latent herpesvirus infections. I have developed a mouse model which has shown that at least three genes are responsible for resistance to HSV. Although preliminary evidence suggests that resistance is immunologically mediated, resistance genes do not seem to be closely linked to the histocompatibility region of the mouse.