Dimethyl sulfoxide blocks herpes simplex virus-1 productive infection in vitro acting at different stages with positive cooperativity. Application of micro-array analysis

Dimethyl sulfoxide (DMSO): a solvent that may solve selected cutaneous clinical challenges

Dimethyl sulfoxide (DMSO) is a clear, odorless liquid, inexpensively produced as a by-product of the wood pulp industry. DMSO's unique chemical properties allow for its broad applications in a wide variety of cutaneous challenges. Widely available in the USA as a solvent, DMSO is FDA-approved only for the treatment of interstitial cystitis and for use as a preservative for organ transplant. DMSO readily penetrates and diffuses through biological membranes. At low concentrations, DMSO exhibits anti-inflammatory, analgesic, diuretic, vasodilator, anti-platelet aggregation, radio-protective, and muscle-relaxing properties. DMSO is also a vigorous scavenger of hydroxyl free radicals, which may explain its observed beneficial effects on skin rejuvenation and recovery from thermal injury. DMSO has a relatively low level of toxicity. DMSO has shown promise in the off-label treatment of basal cell carcinoma, pressure ulcers, scleroderma, herpes simplex, cutaneous fungal infections, and amyloidosis. The potential of DMSO to serve as an independent or adjuvant topical treatment for these conditions is explored in this review.

Dimethyl Sulfoxide Enhances Kaposi’s Sarcoma-Associated Herpesvirus Production During Lytic Replication

Kaposi’s sarcoma-associated herpesvirus (KSHV) is an etiologic agent of Kaposi’s sarcoma, primary effusion lymphoma, and multicentric Castleman disease. In studies of KSHV, efficient virus production and isolation are essential. Reactivation of KSHV can be initiated by treating latently infected cells with chemicals, such as 12-O-tetradecanoyl-phorbol-13-acetate and sodium butyrate. These chemicals have been used as tools to induce lytic replication and viral production in KSHV-producing cell lines. Dimethyl sulfoxide (DMSO) is an organosulfur compound that is frequently used as an aprotic solvent similar to water. In experiments exploring signaling pathways in KSHV-infected cells, DMSO treatment alone as a vehicle affected the lytic gene expression of KSHV. However, to the best of our knowledge, the effects of DMSO on KSHV-producing cells have not yet been reported. Therefore, in this study, we investigated whether DMSO could be used as a reagent to enhance viral production during lytic replication in KSHV-producing cells and assessed the underlying mechanisms. The effects of DMSO on KSHV production were analyzed in iSLK BAC16 cells, which have been widely used for recombinant KSHV production. We found that the production of KSHV virions was significantly increased by treatment with DMSO during the induction of lytic replication. Mechanistically, lytic genes of KSHV were enhanced by DMSO treatment, which was correlated with virion production. Additionally, DMSO induced the phosphorylation of JNK during lytic replication, and inhibition of JNK abolished the effects of DMSO on lytic replication and virion production. Our findings showed that additional treatment with DMSO during the induction of lytic replication significantly improved the yield of KSHV production.

In Vitro Model Systems of Coxsackievirus B3-Induced Myocarditis: Comparison of Commonly Used Cell Lines and Characterization of CVB3-Infected iCell® Cardiomyocytes

Coxsackievirus B3 (CVB3) belongs to the enteroviruses, which are a well-known cause of acute and chronic myocarditis, primarily infecting cardiac myocytes. As primary human cardiomyocytes are difficult to obtain, viral myocarditis is quite frequently studied in vitro in different non-cardiac and cardiac-like cell lines. Recently, cardiomyocytes that have been differentiated from human-induced pluripotent stem cells have been described as a new model system to study CVB3 infection. Here, we compared iCell^® Cardiomyocytes with other cell lines that are commonly used to study CVB3 infection regarding their susceptibility and patterns of infection and the mode of cell death. iCell^® Cardiomyocytes, HeLa cells, HL-1 cells and H9c2 cells were infected with CVB3 (Nancy strain). The viral load, CVB3 RNA genome localization, VP1 expression (including the intracellular localization), cellular morphology and the expression of cell death markers were compared. The various cell lines clearly differed in their permissiveness to CVB3 infection, patterns of infection, viral load, and mode of cell death. When studying the mode of cell death of CVB3-infected iCell^® Cardiomyocytes in more detail, especially regarding the necroptosis key players RIPK1 and RIPK3, we found that RIPK1 is cleaved during CVB3 infection. iCell^® Cardiomyocytes represent well the natural host of CVB3 in the heart and are thus the most appropriate model system to study molecular mechanisms of CVB3-induced myocarditis in vitro. Doubts are raised about the suitability of commonly used cell lines such as HeLa cells, HL-1 cells and H9c2 cells to evaluate molecular pathways and processes occurring in vivo in enteroviral myocarditis.

Application of Dimethyl Sulfoxide as a Therapeutic Agent and Drug Vehicle for Eye Diseases

Dimethyl sulfoxide (DMSO) is an amphipathic molecule widely used as a solvent for water-insoluble substances, cryopreserving, and cell-biological therapies. It has known properties as an inducer of cellular differentiation, a free radical scavenger, and a radioprotectant. In addition, DMSO is used for its various therapeutic and pharmaceutical properties, such as anti-inflammatory, local and systemic analgesic, antibacterial, antifungal, antiviral, and membrane penetration enhancement agents. DMSO treatment can be given orally, intravenously, or topically for a wide range of indications. The administration of DMSO exhibits favorable outcomes in human eye diseases with low to none observed ocular or systemic ocular toxicity. Nevertheless, DMSO is an essential and nonpatentable potential therapeutic agent that remains underexplored and ignored by pharmaceutical developers and ophthalmologists. This current review takes data from experimental and clinical studies that have been published to substantiate the potential therapeutic efficacy of DMSO and stimulate the research of its application in clinical ophthalmology. Given that DMSO is inexpensive, safe, and easily formulated into therapeutic medicinal products and conventional ophthalmological drugs, this compound should be further explored and studied in the treatment of a variety of acute and chronic ocular disorders.

Dual-Acting Zeta-Potential-Changing Micelles for Optimal Mucus Diffusion and Enhanced Cellular Uptake after Oral Delivery

Context: Overcoming the intestinal mucosal barrier can be a challenge in drug delivery. Nanoemulsions with negative zeta potentials can effectively permeate the mucus layer, but those with positive zeta potentials are better taken up by cells; a nanoemulsion with capricious zeta potential from negative to positive can achieve both good permeation and high uptake. Objective: This study aimed to develop dual-acting zeta-potential-amphoteric micelles enabling optimal muco-permeation and enhancement of cellular uptake. Methods: A micellar pre-concentrate was prepared from 15% Labrasol, 15% Kolliphor EL, 30% Kolliphor RH 40, and 40% dimethylsulfoxide. The micellar pre-concentrate was loaded with anionic stearic acid (SA), forming ionic complexes with cationic polymers at a ratio of 25:1 with Eudragit RS 100 and Eudragit RL 100. Blank micelles and those containing complexes were separately diluted in physiological buffers and examined for their droplet sizes, polydispersity indices (PDIs), zeta potentials, and cytotoxicity. The SA release from the micellar complexes was evaluated in 0.1 mM phosphate buffer (pH 6.8) containing 0.001% fluorescein, thereby enabling an instant decrease in fluorescence. Finally, the micelles were loaded with the model drug fluorescein diacetate (FDA) and evaluated for their muco-permeation behavior and cellular uptake. Results: The micellar dilutions formed micelles at the critical micelle concentration (CMC) of 312 µg/mL and showed a uniform average droplet size of 14.2 nm, with a PDI < 0.1. Micellar dilutions were non-cytotoxic when used at 1:100 in a physiological medium. Micelles loaded with ionic complexes achieved a sustained release of 95.5 ± 3.7% of the SA in 180 min. Moreover, the zeta potential of the complex-loaded micelles shifted from −5.4 to +1.8 mV, whereas the blank micelles showed a stabilized zeta potential of −10 mV. Furthermore, the negatively charged blank and complex-loaded micelles exhibited comparable muco-permeation, with an overall average of 58.2 ± 3.7% diffusion of FDA. The complex-loaded micellar droplets, however, provided a significantly higher cellular uptake of the model drug FDA (2.2-fold, p ≤ 0.01) Conclusion: Due to undergoing a shift in zeta potential, the modified micelles significantly enhanced cellular uptake while preserving mucus-permeating properties.

Environmental pollutants modulate RNA and DNA virus-activated miRNA-155 expression and innate immune system responses: Insights into new immunomodulative mechanisms

Many persistent organic pollutants, such as polychlorinated biphenyls (PCBs), have high immunomodulating potentials. Exposure to them, in combination with virus infections, has been shown to aggravate outcomes of the infection, leading to increased viral titers and host mortality. Expression of immune-related microRNA (miR) signaling pathways (by host and/or virus) have been shown to be important in determining these outcomes; there is some evidence to suggest pollutants can cause dysregulation of miRNAs. It was thus hypothesized here that modulation of miRNAs (and associated cytokine genes) by pollutants exerts negative effects during viral infections. To test this, an in vitro study on chicken embryo fibroblasts (CEF) exposed to a PCB mixture (Aroclor 1260) and then stimulated with a synthetic RNA virus (poly(I:C)) or infected with a lymphoma-causing DNA virus (Gallid Herpes Virus 2 [GaHV-2]) was conducted. Using quantitative real-time PCR, expression patterns for mir-155, pro-inflammatory TNFα and IL-8, transcription factor NF-κB1, and anti-inflammatory IL-4 were investigated 8, 12, and 18 h after virus activation. The study showed that Aroclor1260 modulated mir-155 expression, such that a down-regulation of mir-155 in poly(I:C)-treated CEF was seen up to 12 h. Aroclor1260 exposure also increased the mRNA expression of pro-inflammatory genes after 8 h in poly(I:C)-treated cells, but levels in GaHV-2-infected cells were unaffected. In contrast to with Aroclor1260/poly(I:C), Aroclor1260/GaHV-2-infected cells displayed an increase in mir-155 levels after 12 h compared to levels seen with either individual treatment. While after 12 h expression of most evaluated genes was down-regulated (independent of treatment regimen), by 18 h, up-regulation was evident again. In conclusion, this study added evidence that mir-155 signaling represents a sensitive pathway to chemically-induced immunomodulation and indicated that PCBs can modulate highly-regulated innate immune system signaling pathways important in determining host immune response outcomes during viral infections.

Noble Metal Organometallic Complexes Display Antiviral Activity against SARS-CoV-2

SARS-CoV-2 emerged in 2019 as a devastating viral pathogen with no available preventative or treatment to control what led to the current global pandemic. The continued spread of the virus and increasing death toll necessitate the development of effective antiviral treatments to combat this virus. To this end, we evaluated a new class of organometallic complexes as potential antivirals. Our findings demonstrate that two pentamethylcyclopentadienyl (Cp*) rhodium piano stool complexes, Cp*Rh(1,3-dicyclohexylimidazol-2-ylidene)Cl₂ (complex 2) and Cp*Rh(dipivaloylmethanato)Cl (complex 4), have direct virucidal activity against SARS-CoV-2. Subsequent in vitro testing suggests that complex 4 is the more stable and effective complex and demonstrates that both 2 and 4 have low toxicity in Vero E6 and Calu-3 cells. The results presented here highlight the potential application of organometallic complexes as antivirals and support further investigation into their activity.

Synthesis and Evaluation of Some Uracil Nucleosides as Promising Anti-Herpes Simplex Virus 1 Agents

Since herpes simplex virus type 1 (HSV-1) infection is so widespread, several antiviral drugs have been developed to treat it, among which are uracil nucleosides. However, there are major problems with the current medications such as severe side-effects and drug resistance. Here we present some newly synthesized cyclic and acyclic uracil nucleosides that showed very promising activity against HSV-1 compared to acyclovir.

Equine Alphaherpesviruses Require Activation of the Small GTPases Rac1 and Cdc42 for Intracellular Transport

Viruses utilize host cell signaling to facilitate productive infection. Equine herpesvirus type 1 (EHV-1) has been shown to activate Ca2+ release and phospholipase C upon contact with α4β1 integrins on the cell surface. Signaling molecules, including small GTPases, have been shown to be activated downstream of Ca2+ release, and modulate virus entry, membrane remodeling and intracellular transport. In this study, we show that EHV-1 activates the small GTPases Rac1 and Cdc42 during infection. The activation of Rac1 and Cdc42 is necessary for virus-induced acetylation of tubulin, effective viral transport to the nucleus, and cell-to-cell spread. We also show that inhibitors of Rac1 and Cdc42 did not block virus entry, but inhibited overall virus infection. The Rac1 and Cdc42 signaling is presumably orthogonal to Ca2+ release, since Rac1 and Cdc42 inhibitors affected the infection of both EHV-1 and EHV-4, which do not bind to integrins.

RNA Polymerase II Promoter-Proximal Pausing and Release to Elongation Are Key Steps Regulating Herpes Simplex Virus 1 Transcription

Herpes simplex virus 1 (HSV-1) genes are transcribed by cellular RNA polymerase II (Pol II). Expression of viral immediate early (α) genes is followed sequentially by early (β), late (γ₁), and true late (γ₂) genes. We used precision nuclear run-on with deep sequencing to map and to quantify Pol II on the HSV-1(F) genome with single-nucleotide resolution. Approximately 30% of total Pol II relocated to viral genomes within 3 h postinfection (hpi), when it occupied genes of all temporal classes. At that time, Pol II on α genes accumulated most heavily at promoter-proximal pause (PPP) sites located ∼60 nucleotides downstream of the transcriptional start site, while β genes bore Pol II more evenly across gene bodies. At 6 hpi, Pol II increased on γ₁ and γ₂ genes while Pol II pausing remained prominent on α genes. At that time, average cytoplasmic mRNA expression from α and β genes decreased, relative to levels at 3 hpi, while γ₁ relative expression increased slightly and γ₂ expression increased more substantially. Cycloheximide treatment during the first 3 h reduced the amount of Pol II associated with the viral genome and confined most of the remaining Pol II to α gene PPP sites. Inhibition of both cyclin-dependent kinase 9 activity and viral DNA replication reduced Pol II on the viral genome and restricted much of the remaining Pol II to PPP sites.IMPORTANCE These data suggest that viral transcription is regulated not only by Pol II recruitment to viral genes but also by control of elongation into viral gene bodies. We provide a detailed map of Pol II occupancy on the HSV-1 genome that clarifies features of the viral transcriptome, including the first identification of Pol II PPP sites. The data indicate that Pol II is recruited to late genes early in infection. Comparing α and β gene occupancy at PPP sites and gene bodies suggests that Pol II is released more efficiently into the bodies of β genes than α genes at 3 hpi and that repression of α gene expression late in infection is mediated by prolonged promoter-proximal pausing. In addition, DNA replication is required to maintain full Pol II occupancy on viral DNA and to promote elongation on late genes later in infection.

Modification of pH Conferring Virucidal Activity on Dental Alginates

To formulate an alginate dental impression material with virucidal properties, experimental alginate dental impression materials were developed and the formulations adjusted in order to study the effect on pH profiles during setting. Commercially available materials served as a comparison. Eight experimental materials were tested for antiviral activity against Herpes Simplex Virus type 1 (HSV-1). Changing the amount of magnesium oxide (MgO) used in the experimental formulations had a marked effect on pH. Increasing MgO concentration corresponded with increased pH values. All experimental materials brought about viral log reductions ranging between 0.5 and 4.0 over a period of 4 h. The material with the lowest pH was the most effective. The current work highlights the very important role of MgO in controlling pH profiles. This knowledge has been applied to the formulation of experimental alginates; where materials with pH values of approximately 4.2-4.4 are able to achieve a significant log reduction when assayed against HSV-1.

Volatile emanations from in vitro airway cells infected with human rhinovirus

Respiratory viral infections such as human rhinovirus (HRV) can lead to substantial morbidity and mortality, especially in people with underlying lung diseases such as asthma and COPD. One proposed strategy to detect viral infections non-invasively is by volatile organic compound (VOC) assessment via analysis of exhaled breath. The epithelial cells are one of the most important cell lines affected during respiratory infections as they are the first line of pathogen defense. Efforts to discover infection-specific biomarkers can be significantly aided by understanding the VOC emanations of respiratory epithelial cells. Here we test the hypothesis that VOCs obtained from the headspace of respiratory cell culture will differentiate healthy cells from those infected with HRV. Primary human tracheobronchial cells were cultured and placed in a system designed to trap headspace VOCs. HRV-infected cells were compared to uninfected control cells. In addition, cells treated with heat-killed HRV and poly(I:C), a TLR3 agonist, were compared to controls. The headspace was sampled with solid-phase microextraction fibers and VOCs were analyzed by gas chromatography/mass spectrometry. We determined differential expression of compounds such as aliphatic alcohols, branched hydrocarbons, and dimethyl sulfide by the infected cells, VOCs previously associated with oxidative stress and bacterial infection. We saw no major differences between the killed-HRV, poly(I:C), and control cell VOCs. We postulate that these compounds may serve as biomarkers of HRV infection, and that the production of VOCs is not due to TLR3 stimulation but does require active viral replication. Our novel approach may be used for the in vitro study of other important respiratory viruses, and ultimately it may aid in identifying VOC biomarkers of viral infection for point-of-care diagnostics.

Dimethyl sulfoxide: history, chemistry, and clinical utility in dermatology

Dimethyl sulfoxide is a colorless liquid derived as a by-product from wood pulp in the production of paper. This colorless liquid found immediate application as a polar, aprotic solvent miscible with water and able to dissolve an enormous catalog of polar and nonpolar small molecules. It is presently scarcely used in dermatology, but given its useful properties as a penetration-enhancing solvent excipient and active anti-inflammatory pharmaceutical agent, dimethyl sulfoxide has the potential to be used in a much broader capacity. The authors review the history, chemistry, and clinical utility of dimethyl sulfoxide as it pertains to dermatology.

Evaluation of antiviral activities of curcumin derivatives against HSV-1 in Vero cell line

Antiviral drug resistance is one of the most common problems in medicine, and, therefore, finding new antiviral agents, especially from natural resources, seems to be necessary. This study was designed to assay the antiviral activity of curcumin and its new derivatives like gallium-curcumin and Cu-curcumin on replication of HSV-1 in cell culture. The research was performed as an in vitro study in which the antiviral activity of different concentrations of three substances including curcumin, Gallium-curcumin and Cu-curcumin were tested on HSV-1. The cytotoxicity of the tested compounds was also evaluated on the Vero cell line. The CC50 values for curcumin, gallium-curcumin and Cu-curcumin were 484.2 microg/mL, 255.8 microg/mL and 326.6 microg/mL, respectively, and the respective IC50 values 33.0 microg/mL, 13.9 microg/mL and 23.1 microg/mL. The calculated SI values were 14.6, 18.4 and 14.1, respectively. The results showed that curcumin and its new derivatives have remarkable antiviral effects on HSV-1 in cell culture.

A simple method for Alexa Fluor dye labelling of dengue virus

Dengue virus causes frequent and cyclical epidemics throughout the tropics, resulting in significant morbidity and mortality rates. There is neither a specific antiviral treatment nor a vaccine to prevent epidemic transmission. The lack of a detailed understanding of the pathogenesis of the disease complicates these efforts. The development of methods to probe the interaction between the virus and host cells would thus be useful. Direct fluorescence labelling of virus would facilitate the visualization of the early events in virus-cell interaction. This report describes a simple method of labelling of dengue virus with Alexa Fluor succinimidyl ester dye dissolved directly in the sodium bicarbonate buffer that yielded highly viable virus after labelling. Alexa Fluor dyes have superior photostability and are less pH-sensitive than the common dyes, such as fluorescein and rhodamine, making them ideal for studies on cellular uptake and endosomal transport of the virus. The conjugation of Alexa Fluor dye did not affect the recognition of labelled dengue virus by virus-specific antibody and its putative receptors in host cells. This method could have useful applications in virological studies.

Quantitative comparison of the HSV-1 and HSV-2 transcriptomes using DNA microarray analysis

The genomes of human herpes virus type-1 and type-2 share a high degree of sequence identity; yet, they exhibit important differences in pathology in their natural human host as well as in animal host and cell cultures. Here, we report the comparative analysis of the time and relative abundance profiles of the transcription of each virus type (their transcriptomes) using parallel infections and microarray analysis using HSV-1 probes which hybridize with high efficiency to orthologous HSV-2 transcripts. We have confirmed that orthologous transcripts belong to the same kinetic class; however, the temporal pattern of accumulation of 4 transcripts (U(L)4, U(L)29, U(L)30, and U(L)31) differs in infections between the two virus types. Interestingly, the protein products of these transcripts are all involved in nuclear organization and viral DNA localization. We discuss the relevance of these findings and whether they may have potential roles in the pathological differences of HSV-1 and HSV-2.

The cellular response to herpes simplex virus type 1 (HSV-1) during latency and reactivation

In order to learn more about the cellular response to viral gene activity during latency and reactivation of herpes simplex virus type 1 (HSV-1), the authors have employed microarray analysis. On an array of about 1200 cellular genes, approximately 56 genes were found to be differentially regulated in infected trigeminal ganglia of mice, compared to uninfected mice, during latency and reactivation. Of these genes, 10 were examined more closely using quantitative real-time polymerase chain reaction (PCR) to confirm the microarray results. Genes involved in interferon and other signaling pathways appeared to predominate in response to a latent or reactivating HSV infection. Interestingly, some genes found to be differentially regulated in latently infected ganglia are neuronal-specific genes (pro-opiomelanocortinin; zinc finger proteins of the cerebellum 1 and 2). During reactivation, the involvement of several cell signaling molecules that may be important for the initiation of an HSV infection was observed, including various receptors and molecules involved in cell-cell spread.

The TATGARAT box of the HSV-1 ICP27 gene is essential for immediate early expression but not critical for efficient replication in vitro or in vivo

We constructed a recombinant virus containing a promoter mutation altering the immediate-early expression of the HSV-1 ICP27 transcript, ICP27DeltaSma, which contains a deletion of the "TATGARAT" and surrounding sequences, but retains the rest of the ICP27 promoter. This mutant does not exhibit immediate-early expression of ICP27 using criteria of expression in the absence of de novo protein synthesis and earliest expression in the kinetic cascade. While transcript abundance at 1h after infection at 0.1 PFU/cell in mouse embryo fibroblasts was significantly altered compared to infections with wt -rescues, by 4 h after infection these differences were diminished or absent. Consistent with this observation, levels of some critical proteins were reduced in the mutant as compared to rescue infections at the earliest times tested, but were equivalent by 8-12 h pi. Further, both single and multi-step virus replication was equivalent with both mutants and rescues. Thus, altering the immediate early kinetics of ICP27 leads to a sub-optimal quantitative lag-phase in gene expression but without consequence to replication fitness in vitro . Infections in vivo also revealed the ability of mutant and rescue virus to invade the CNS of mice following footpad injections was equivalent. The nature of the role of immediate-early ICP27 expression is discussed in light of these observations.

Immediate-early expression of the herpes simplex virus type 1 ICP27 transcript is not critical for efficient replication in vitro or in vivo

We constructed a promoter mutation altering the immediate-early expression of the herpes simplex virus type 1 (HSV-1) ICP27 transcript and its cognate wild-type rescue viruses in order to assess the role of the ICP27 protein in the earliest stages of viral infection by global transcriptional analysis with a DNA microarray. This mutant, ICP27/VP16, replaces the whole ICP27 promoter/enhancer with the VP16 promoter. It demonstrates loss of immediate-early expression of ICP27 according to the criteria expression in the absence of de novo protein synthesis and earliest expression in the kinetic cascade. Significant differences in relative transcript abundances between the mutant and wild-type rescue viruses were limited at the earliest times measured and not evident at all by 4 h after infection. Consistent with this observation, levels of some critical proteins were reduced in the mutant as compared to rescue virus infections at the earliest times tested, but were equivalent by 8 h postinfection. Further, both single and multistep levels of virus replication were equivalent with both mutant and rescue viruses. Thus, altering the immediate-early kinetics of ICP27 leads to a suboptimal quantitative lag phase in gene expression but without consequence for replication fitness in vitro. Infections in vivo also revealed equivalent ability of mutant and rescue viruses to invade the central nervous system of mice following footpad injections. Limitations to an immediate-early role of ICP27 in the biology of HSV are discussed in light of these observations.

Gene expression profiling in the HSV-1 latently infected mouse trigeminal ganglia following hyperthermic stress

PURPOSE

To assess gene expression in herpes simplex virus type 1 (HSV-1) latent mouse trigeminal ganglia (TG) at 6 and 24 hours after hyperthermic stress.

METHODS

Uninfected and HSV-1 latently infected mice were heat stressed (43 degrees C, 10 min). TG from six groups of mice were studied: 1) uninfected, not stressed, 2) uninfected, heat-stressed, sacrificed at 6 hours after hyperthermia, 3) uninfected, heat-stressed, sacrificed at 24 hours after hyperthermia, 4) latently infected, not stressed, 5) latently infected, heat-stressed, sacrificed at 6 hours after hyperthermia, 6) latently infected, heat-stressed, sacrificed at 24 hours after hyperthermia. Poly A(+) mRNA from the TG of each group of mice was reverse transcribed, labeled with (32)P, and incubated on a nylon gene array membrane. The genes showing the largest signal-to-control changes (varying by a factor of at least 1.27-fold) were considered to have undergone significant change in expression.

RESULTS

Six hours after heat stress the genes whose expression was altered included the FK506-binding protein gene (decreased), the T-complex protein 1 alpha subunit gene (increased), and the 94-kDa glucose-regulated protein gene (increased in uninfected TG, decreased in infected TG). Heat stress increased expression of the DNA excision repair protein ERCC5 gene 24 hours after the treatment. Genes previously reported to exhibit increased transcription 1 hour after stress did not continue to show significant transcriptional activation at 6 or 24 hours.

CONCLUSION

Altered gene expression at 6 and 24 hours after heat stress was different from previously reported changes in gene expression 1 hour after hyperthermia in HSV-1 latently infected mice.