Curcumol inhibits encephalomyocarditis virus by promoting IFN-ß secretion.

BACKGROUND: Encephalomyocarditis virus (EMCV) infection can cause reproductive failure in sows and acute myocarditis and sudden death in piglets. It has caused huge economic losses to the global pig industry and that is why it is necessary to develop effective new treatment compounds. Zedoary turmeric oil has been used for treating myocarditis. Curcumol extracted from the roots of curcuma is one of the main active ingredient of zedoary turmeric oil. The anti-EMCV activity of curcumol along with the molecular mechanisms involved with a focus on IFN-ß signaling pathway was investigated in this study. METHOD: 3-(4,5-dimethyithiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the maximum non-toxic concentration (MNTC), 50% cytotoxic concentration (CC50), maximum inhibition rate (MIR) and 50% effective concentration (EC50) against EMCV. Through EMCV load, the anti-viral effect of curcumol was quantitatively determined using real-time quantitative PCR (qPCR). The effect of curcumol on the expression of IFN-ß was investigated using real-time quantitative PCR and ELISA. Western blot was used to determine the amounts of MDA5, MAVS, TANK, IRF3 and P-IRF3 proteins in human embryonic kidney 293 T (HEK-293 T) cells infected with EMCV. RESULTS: The results of MTT showed that compared with the ribavirin positive control group, the maximum inhibition ratio (MIR) of curcumol was greater but the selection index (SI) value was much smaller than that of ribavirin. The results of qPCR showed that curcumol and ribavirin significantly reduced the replication of EMCV in HEK-293 T cells. The curcumol (0.025 mg/mL) treatment has significantly increased IFN-ß mRNA expression in the EMCV-infected HEK-293 T cells while ribavirin treatment did not. The results of ELISA showed that curcumol (0.025 mg/mL and 0.0125 mg/mL) has significantly increased the expression of IFN-ß protein in EMCV-infected HEK-293 T cells. The results of Western blot showed that curcumol can inhibit the degradation of TANK protein mediated by EMCV and promote the expression of MDA5 and P-IRF3, while the protein expression level of MAVS and IRF3 remain unchanged. CONCLUSION: Curcumol has biological activity against EMCV which we suggest that IFN-ß signaling pathway is one of its mechanisms.

Inhibition of oxidative metabolism by nitric oxide restricts EMCV replication selectively in pancreatic beta-cells.

Environmental factors, such as viral infection, are proposed to play a role in the initiation of autoimmune diabetes. In response to encephalomyocarditis virus (EMCV) infection, resident islet macrophages release the pro-inflammatory cytokine IL-1ß, to levels that are sufficient to stimulate inducible nitric oxide synthase (iNOS) expression and production of micromolar levels of the free radical nitric oxide in neighboring ß-cells. We have recently shown that nitric oxide inhibits EMCV replication and EMCV-mediated ß-cell lysis and that this protection is associated with an inhibition of mitochondrial oxidative metabolism. Here we show that the protective actions of nitric oxide against EMCV infection are selective for ß-cells and associated with the metabolic coupling of glycolysis and mitochondrial oxidation that is necessary for insulin secretion. Inhibitors of mitochondrial respiration attenuate EMCV replication in ß-cells, and this inhibition is associated with a decrease in ATP levels. In mouse embryonic fibroblasts (MEFs), inhibition of mitochondrial metabolism does not modify EMCV replication or decrease ATP levels. Like most cell types, MEFs have the capacity to uncouple the glycolytic utilization of glucose from mitochondrial respiration, allowing for the maintenance of ATP levels under conditions of impaired mitochondrial respiration. It is only when MEFs are forced to use mitochondrial oxidative metabolism for ATP generation that mitochondrial inhibitors attenuate viral replication. In a ß-cell selective manner, these findings indicate that nitric oxide targets the same metabolic pathways necessary for glucose stimulated insulin secretion for protection from viral lysis.

Impaired upregulation of Stat2 gene restrictive to pancreatic ß-cells is responsible for virus-induced diabetes in DBA/2 mice.

Viral infection is a putative causal factor for the development of type 1 diabetes, but the exact pathogenic mechanism of virus-induced diabetes (VID) remains unclear. Here, to identify the critical factors that regulate VID, we analyzed encephalomyocarditis D (EMC-D) VID-sensitive DBA/2 mice in comparison with resistant B6 mice. EMC-D virus-induced cell death occurred more frequently in DBA/2 ß-cells than in B6 ß-cells with 100U/ml IFN-ß priming in vitro. We therefore purified ß-cells using flow cytometry from mice two days after EMC-D virus infection and subjected them to microarray analysis. As a results, innate immune response pathway was found to be enriched in B6 ß-cells. The signal transducer and activator of transcription 2 (Stat2) gene interacted with genes in the pathway. Stat2 gene expression levels were lower in DBA/2 mice than in B6 mice, restrictive to ß-cells. Moreover, administration of IFN-ß failed to upregulate Stat2 gene in DBA/2 ß-cells than in those of B6 in vivo. The viral titer significantly increased only in the DBA/2 pancreas. Thus, these provided data suggest that impaired upregulation of Stat2 gene restrictive to ß-cells at the early stage of infection is responsible for VID development in DBA/2 mice.

A polymorphic residue that attenuates the antiviral potential of interferon lambda 4 in hominid lineages.

As antimicrobial signalling molecules, type III or lambda interferons (IFNλs) are critical for defence against infection by diverse pathogens, including bacteria, fungi and viruses. Counter-intuitively, expression of one member of the family, IFNλ4, is associated with decreased clearance of hepatitis C virus (HCV) in the human population; by contrast, a natural frameshift mutation that abrogates IFNλ4 production improves HCV clearance. To further understand how genetic variation between and within species affects IFNλ4 function, we screened a panel of all known extant coding variants of human IFNλ4 for their antiviral potential and identify three that substantially affect activity: P70S, L79F and K154E. The most notable variant was K154E, which was found in African Congo rainforest 'Pygmy' hunter-gatherers. K154E greatly enhanced in vitro activity in a range of antiviral (HCV, Zika virus, influenza virus and encephalomyocarditis virus) and gene expression assays. Remarkably, E154 is the ancestral residue in mammalian IFNλ4s and is extremely well conserved, yet K154 has been fixed throughout evolution of the hominid genus Homo, including Neanderthals. Compared to chimpanzee IFNλ4, the human orthologue had reduced activity due to amino acid K154. Comparison of published gene expression data from humans and chimpanzees showed that this difference in activity between K154 and E154 in IFNλ4 correlates with differences in antiviral gene expression in vivo during HCV infection. Mechanistically, our data show that the human-specific K154 negatively affects IFNλ4 activity through a novel means by reducing its secretion and potency. We thus demonstrate that attenuated activity of IFNλ4 is conserved among humans and postulate that differences in IFNλ4 activity between species contribute to distinct host-specific responses to-and outcomes of-infection, such as HCV infection. The driver of reduced IFNλ4 antiviral activity in humans remains unknown but likely arose between 6 million and 360,000 years ago in Africa.

Treatment of Theiler's virus-induced demyelinating disease with teriflunomide.

Teriflunomide is an oral therapy approved for the treatment of relapsing remitting multiple sclerosis (MS), showing both anti-inflammatory and antiviral properties. Currently, it is uncertain whether one or both of these properties may explain teriflunomide's beneficial effect in MS. Thus, to learn more about its mechanisms of action, we evaluated the effect of teriflunomide in the Theiler's encephalomyelitis virus-induced demyelinating disease (TMEV-IDD) model, which is both a viral infection and an excellent model of the progressive disability of MS. We assessed the effects of the treatment on central nervous system (CNS) viral load, intrathecal immune response, and progressive neurological disability in mice intracranially infected with TMEV. In the TMEV-IDD model, we showed that teriflunomide has both anti-inflammatory and antiviral properties, but there seemed to be no impact on disability progression and intrathecal antibody production. Notably, benefits in TMEV-IDD were mostly mediated by effects on various cytokines produced in the CNS. Perhaps the most interesting result of the study has been teriflunomide's antiviral activity in the CNS, indicating it may have a role as an antiviral prophylactic and therapeutic compound for CNS viral infections.

Neuroprotection mediated by inhibition of calpain during acute viral encephalitis.

Neurologic complications associated with viral encephalitis, including seizures and cognitive impairment, are a global health issue, especially in children. We previously showed that hippocampal injury during acute picornavirus infection in mice is associated with calpain activation and is the result of neuronal death triggered by brain-infiltrating inflammatory monocytes. We therefore hypothesized that treatment with a calpain inhibitor would protect neurons from immune-mediated bystander injury. C57BL/6J mice infected with the Daniel's strain of Theiler's murine encephalomyelitis virus were treated with the FDA-approved drug ritonavir using a dosing regimen that resulted in plasma concentrations within the therapeutic range for calpain inhibition. Ritonavir treatment significantly reduced calpain activity in the hippocampus, protected hippocampal neurons from death, preserved cognitive performance, and suppressed seizure escalation, even when therapy was initiated 36 hours after disease onset. Calpain inhibition by ritonavir may be a powerful tool for preserving neurons and cognitive function and preventing neural circuit dysregulation in humans with neuroinflammatory disorders.

Substance P receptor antagonism: a potential novel treatment option for viral-myocarditis.

Viral-myocarditis is an important cause of heart failure for which no specific treatment is available. We previously showed the neuropeptide substance P (SP) is associated with the pathogenesis of murine myocarditis caused by encephalomyocarditis virus (EMCV). The current studies determined if pharmacological inhibition of SP-signaling via its high affinity receptor, NK1R and downstream G-protein, Ras homolog gene family, member-A (RhoA), will be beneficial in viral-myocarditis. Aprepitant (1.2 mg/kg), a SP-receptor antagonist, or fasudil (10 mg/kg), a RhoA inhibitor, or saline control was administered daily to mice orally for 3 days, prior to, or 5 days following, intraperitoneal infection with and without 50 PFU of EMCV, following which disease assessment studies, including echocardiogram and cardiac Doppler were performed in day 14 after infection. Pretreatment and posttreatment with aprepitant significantly reduced mortality, heart and cardiomyocyte size, and cardiac viral RNA levels (P < 0.05 all, ANOVA). Only aprepitant pretreatment improved heart functions; it significantly decreased end systolic diameter, improved fractional shortening, and increased peak aortic flow velocity (P < 0.05 all, ANOVA). Pre- or posttreatment with fasudil did not significantly impact disease manifestations. These findings indicate that SP contributes to cardiac-remodeling and dysfunction following ECMV infection via its high affinity receptor, but not through the Rho-A pathway. These studies suggest that SP-receptor antagonism may be a novel therapeutic-option for patients with viral-myocarditis.

[Substances from pyrolised tissues of reptile carcases differently modulate immunity of mammals of both sexes].

Substances with gender action on immunity were detected in water soluble hydrolised matter from reptile carcases. The gender action was shown on isolated blood neutrophils, whole blood and in vivo by the antiviral activity on experimental animals, contaminated with three types of viruses: Herpes simplex type 1, the virus of encephalomyocarditis and the virus of hepatitis of mice. The possible mechanism of the inhibitory action on the male immunity was associated with the protein kinase cascade, including protein kinase C, activated by phorbolmyristate in the cells of the immune system.

IFNγ influences type I interferon response and susceptibility to Theiler's virus-induced demyelinating disease.

Theiler's murine encephalomyelitis virus (TMEV) induces a demyelinating disease in susceptible SJL mice that has similarities to multiple sclerosis in humans. TMEV infection of susceptible mice leads to a persistent virus infection of the central nervous system (CNS), which promotes the development of demyelinating disease associated with an inflammatory immune response in the CNS. TMEV infection of resistant C57BL6 mice results in viral clearance without development of demyelinating disease. Interestingly, TMEV infection of resistant mice deficient in IFNγ leads to a persistent virus infection in the CNS and development of demyelinating disease. We have previously shown that the innate immune response affects development of TMEV- induced demyelinating disease, thus we wanted to determine the role of IFNγ during the innate immune response. TMEV-infected IFNγ-deficient mice had an altered innate immune response, including reduced expression of innate immune cytokines, especially type I interferons. Administration of type I interferons, IFNα and IFNß, to TMEV-infected IFNγ-deficient mice during the innate immune response restored the expression of innate immune cytokines. Most importantly, administration of type I interferons to IFNγ-deficient mice during the innate immune response decreased the virus load in the CNS and decreased development of demyelinating disease. Microglia are the CNS resident immune cells that express innate immune receptors. In TMEV-infected IFNγ-deficient mice, microglia had reduced expression of innate immune cytokines, and administration of type I interferons to these mice restored the innate immune response by microglia. In the absence of IFNγ, microglia from TMEV-infected mice had reduced expression of some innate immune receptors and signaling molecules, especially IRF1. These results suggest that IFNγ plays an important role in the innate immune response to TMEV by enhancing the expression of innate immune cytokines, especially type I interferons, which directly affects the development of demyelinating disease.

Therapeutic effects of anti-Delta1 mAb on Theiler's murine encephalomyelitis virus-induced demyelinating disease.

We examined the role of Notch ligand Delta-like 1 (Delta1) in the development of Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease (TMEV-IDD). Blocking of Delta1 by anti-Delta1 monoclonal antibody (mAb) in the effector phase significantly suppressed the disease development of TMEV-IDD both clinically and histologically. The number of infiltrating inflammatory mononuclear cells in the spinal cords was also decreased in mice treated with anti-Delta1 mAb at the effector phase. Flow cytometric analysis of cytokine staining revealed that IFN-γ- or IL-4-producing CD4(+) splenocytes were significantly decreased in mice treated with anti-Delta1 mAb in the spleens, whereas IL-10-producing CD4(+) splenocytes were increased. Furthermore, IFN-γ-, TNF-α-, IL-4-, or IL-10-producing CD4(+) cells were decreased in spinal cords, and IL-17-producing CD4(+) cells were increased. These data suggest that Delta1 may play important roles in the development of TMEV-IDD and that antibodies to Delta1 could be used as a novel therapeutic treatment of demyelinating diseases such as human multiple sclerosis.

A cannabigerol quinone alleviates neuroinflammation in a chronic model of multiple sclerosis.

Phytocannabinoids like ∆(9)-tetrahydrocannabinol (THC) and cannabidiol (CBD) show a beneficial effect on neuroinflammatory and neurodegenerative processes through cell membrane cannabinoid receptor (CBr)-dependent and -independent mechanisms. Natural and synthetic cannabinoids also target the nuclear receptor peroxisome proliferator-activated receptor-gamma (PPARγ), an attractive molecular target for the treatment of neuroinflammation. As part of a study on the SAR of phytocannabinoids, we have investigated the effect of the oxidation modification in the resorcinol moiety of cannabigerol (CBG) on CB(1), CB(2) and PPARγ binding affinities, identifying cannabigerol quinone (VCE-003) as a potent anti-inflammatory agent. VCE-003 protected neuronal cells from excitotoxicity, activated PPARγ transcriptional activity and inhibited the release of pro-inflammatory mediators in LPS-stimulated microglial cells. Theiler's murine encephalomyelitis virus (TMEV) model of multiple sclerosis (MS) was used to investigate the anti-inflammatory activity of this compound in vivo. Motor function performance was evaluated and the neuroinflammatory response and gene expression pattern in brain and spinal cord were studied by immunostaining and qRT-PCR. We found that VCE-003 ameliorated the symptoms associated to TMEV infection, decreased microglia reactivity and modulated the expression of genes involved in MS pathophysiology. These data lead us to consider VCE-003 to have high potential for drug development against MS and perhaps other neuroinflammatory diseases.

The effect of FTY720 in the Theiler's virus model of multiple sclerosis.

FTY720 (fingolimod) has demonstrated efficacy in multiple sclerosis (MS). We evaluated the effects of FTY720 on progressive disability, viral load, and antibody responses in mice infected with Theiler's murine encephalomyocarditis virus (TMEV). FTY720 and phosphorylated FTY720 (FTY720-P) were detected in the brain after intraperitoneal injection of the drug. Bioactivity of FTY720 was confirmed by reduced numbers of mononuclear cells in the spleen and blood after treatment. No significant differences were found in disability progression, viral load, and serum antibody responses between the FTY720-treated versus the PBS-treated mice. There was less production of IgG within the CNS in the FTY-treated group on some measures.

The endocannabinoid anandamide downregulates IL-23 and IL-12 subunits in a viral model of multiple sclerosis: evidence for a cross-talk between IL-12p70/IL-23 axis and IL-10 in microglial cells.

Theiler's virus (TMEV) infection of the central nervous system (CNS) induces an immune-mediated demyelinating disease in susceptible mouse strains and serves as a relevant infection model for human multiple sclerosis (MS). The endocannabinoid system represents a novel therapeutic target for autoimmune and chronic inflammatory diseases due to its anti-inflammatory properties by regulating cytokine network. IL-12p70 and IL-23 are functionally related heterodimeric cytokines that play a crucial role in the pathogenesis of MS. In the present study we showed that the endocannabinoid anandamide (AEA) downregulated the gene expression of IL-12p70 and IL-23 forming subunits mRNAs in the spinal cord of TMEV-infected mice and ameliorated motor disturbances. This was accompanied by significant decreases on the serological levels of IL-12p70/IL-23 and more interestingly, of IL-17A. In contrast, serum levels of IL-10 resulted elevated. In addition, we studied the signalling pathways involved in the regulation of IL-12p70/IL-23 and IL-10 expression in TMEV-infected microglia and addressed the possible interactions of AEA with these pathways. AEA acted through the ERK1/2 and JNK pathways to downregulate IL-12p70 and IL-23 while upregulating IL-10. These effects were partially mediated by CB2 receptor activation. We also described an autocrine circuit of cross-talk between IL-12p70/IL-23 and IL-10, since endogenously produced IL-10 negatively regulates IL-12p70 and IL-23 cytokines in TMEV-infected microglia. This suggests that by altering the cytokine network, AEA could indirectly modify the type of immune responses within the CNS. Accordingly, pharmacological modulation of endocannabinoids might be a useful tool for treating neuroinflammatory diseases.

Ameliorating effects of anti-Dll4 mAb on Theiler's murine encephalomyelitis virus-induced demyelinating disease.

We examined the role of Notch ligand Delta-like 4 (Dll4) in the development of Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease (TMEV-IDD). Treatment with mAb to Dll4, especially during the effector phase, resulted in significant suppression of the disease development both clinically and histologically. The number of infiltrating mononuclear inflammatory cells in the spinal cords was also decreased in mice treated with anti-Dll4 mAb. Semi-quantitative analysis of mRNA by using real-time PCR revealed that mRNAs of T(h)1-derived cytokines such as IFN-gamma and T(h)17-derived cytokines such as IL-17 were decreased in mice treated with anti-Dll4 mAb, whereas those of T(h)2-derived cytokines such as IL-4 and IL-10 were not. Flow cytometric analysis of cytokines indicated that there were no significant differences between mAb-treated mice and control mice in the relative frequency of splenic T(h)1 and T(h)2. However, absolute cell numbers of T(h)1-derived cytokine-producing cells in spinal cord were markedly decreased in mice treated with anti-Dll4 mAb in effector phase compared with control mice treated with non-specific IgG. These data suggest that Dll4 is critically involved in the pathogenesis of TMEV-IDD and that antibodies to Dll4 could be used as a novel therapeutic treatment of demyelinating diseases such as human multiple sclerosis.

Myeloid cells are tunable by a polyanionic polysaccharide derivative and co-determine host rescue from lethal virus infection.

Insight into molecular and cellular mechanisms of innate immunity is critical to understand viral pathogenesis and immunopathology and might be exploited for therapy. Whereas the molecular mechanisms of the IFN defense are well established, cellular mechanisms of antiviral immunity are only emerging, and their pharmacological triggering remains unknown. COAM is a polysaccharide derivative with antiviral activity but without comprehension about its mechanism of action. The COAM mixture was fractionated, and prophylactic treatment of mice with COAM polymers of high MW resulted in a conversion from 100% lethal mengovirus infection to an overall survival rate of 93% without obvious clinical sequelae. Differential and quantitative analysis of peritoneal leukocytes demonstrated that COAM induced a profound influx of neutrophils. Selective cell depletion experiments pointed toward neutrophils and macrophages as key effector cells in the rescue of mice from lethal mengovirus. COAM was able to induce mRNA and protein expression of the mouse neutrophil chemokine GCP-2. Binding of GCP-2 to COAM was demonstrated in solution and confirmed by SPR technology. Although COAM was not chemotactic for neutrophils, COAM-anchored muGCP-2 retained chemotactic activity for human and mouse neutrophils. In conclusion, this study established that COAM rescued mice from acute and lethal mengovirus infection by recruiting antiviral leukocytes to the site of infection, as proposed through the induction, binding, and concentration of endogenous chemokines. These findings reinforce the role of neutrophils and macrophages as critical cells that can be manipulated toward antiviral defense.

Effects of free immunoglobulin light chains on viral myocarditis.

RATIONALE: In recent work, we have demonstrated a crucial role of mast cells in the development of viral myocarditis. Viral infection could lead to increased synthesis of free immunoglobulin light chains (FLC) and our earlier work showed that FLC can trigger mast cell activation. OBJECTIVE: We studied the possible involvement of FLC in the pathogenesis of viral myocarditis, and therapeutic effects of FLC using an animal model of viral myocarditis. METHODS AND RESULTS: DBA/2 mice were inoculated intraperitoneally with encephalomyocarditis (EMC) virus. Serum levels and concentrations in the heart of kappa FLC on day 14 in mice inoculated with EMC virus were significantly increased compared with controls. Myocardial viral concentration was significantly inhibited, the area of myocardial lesions was smaller in mice treated with kappa or lambda FLC, and survival of mice given FLC significantly improved. In contrast, an FLC antagonist deteriorated myocarditis. kappa and lambda FLC chains inhibited EMC viral replication in human amnion cells in vitro. lambda FLC significantly increased the gene expression of interleukin-10 in the heart which was previously shown to improve viral myocarditis when given exogenously. FLC also tended to increase the gene expressions of interferon-alpha and -gamma in the heart mice. CONCLUSIONS: FLC have antiviral and antiinflammatory effects and improved viral myocarditis in mice. FLC may be promising agents for the treatment of viral myocarditis.

Anti-inflammatory effects of eplerenone on viral myocarditis.

AIMS: Inflammation contributes to increased cardiovascular morbidity and mortality associated with activation of the renin-angiotensin-aldosterone system. The aim of this study was to investigate whether eplerenone, a selective aldosterone receptor antagonist, has anti-inflammatory effects on viral myocarditis. METHODS AND RESULTS: Four-week-old inbred male DBA/2 mice were inoculated intraperitoneally with 10 plaque-forming units (pfu) of the encephalomyocarditis (EMC) virus. Mice were fed with standard chow (control) or with chow containing 2.5 mg/kg of eplerenone, starting either on day 0 (inoculation) or day 7. Survival at 28 days was significantly higher in the mice which started eplerenone treatment on day 0 (35 vs. 15% in controls, each n = 40, P < 0.05). The area of myocardial fibrosis on day 28 was significantly smaller in the eplerenone-treated mice than in controls (19.8 +/- 2.6%, n = 14, vs. 33.4 +/- 5.4%, n = 6, mean +/- SEM, P < 0.05). Gene expression of mouse mast cell proteases-4 and -5, matrix metalloproteinase-9, and type I procollagen on day 6 after EMC virus inoculation was significantly decreased in the hearts of eplerenone-treated mice. CONCLUSION: These results suggest that eplerenone has anti-inflammatory effects, and exerts its beneficial effects on viral myocarditis by suppression of genes related to mast cells and cardiac remodelling in the hearts of mice.

Role of the innate immune system in acute viral myocarditis.

Although the adaptive immune system is thought to play an important role in the pathogenesis of viral myocarditis, the role of the innate immune system has not been well defined. To address this deficiency, we employed a unique line of mice that harbor a genomic "knock in" of a mutated TNF gene lacking the AU rich element (TNF(ARE/ARE)) that is critical for TNF mRNA stability and translation, in order to examine the contribution of the innate immune system in encephalomyocarditis-induced myocarditis (EMCV). Heterozygous mice (TNF(ARE/+)) were infected with 500 plaque-forming units of EMCV. TNF(ARE/+)mice had a significantly higher 14-day mortality and myocardial inflammation when compared to littermate control mice. Virologic studies showed that the viral load at 14 days was significantly lower in the hearts of TNF(ARE/+) mice. TNF(ARE/+) mice had an exaggerated proinflammatory cytokine and chemokine response in the heart following EMCV infection. Modulation of the innate immune response in TNF(ARE/+) mice by the late administration of prednisolone resulted in a significant improvement in survival and decreased cardiac inflammation, whereas early administration of prednisolone resulted in a blunted innate response and increased mortality in littermate control mice. Viewed together, these data suggest that the duration and degree of activation of the innate immune system plays a critical role in determining host outcomes in experimental viral myocarditis.

Detection and characterization of altered conformations of protein pharmaceuticals using complementary mass spectrometry-based approaches.

Unlike small-molecule drugs, the conformational properties of protein biopharmaceuticals in solution are influenced by a variety of factors that are not solely defined by their covalent chemical structure. Since the conformation (or higher order structure) of a protein is a major modulator of its biological activity, the ability to detect changes in both the higher order structure and conformational dynamics of a protein, induced by an array of extrinsic factors, is of central importance in producing, purifying, and formulating a commercial biopharmaceutical with consistent therapeutic properties. In this study we demonstrate that two complementary mass spectrometry-based approaches (analysis of ionic charge-state distribution and hydrogen/deuterium exchange) can be a potent tool in monitoring conformational changes in protein biopharmaceuticals. The utility of these approaches is demonstrated by detecting and characterizing conformational changes in the biopharmaceutical product interferon beta-1a (IFN-beta-1a). The protein degradation process was modeled by inducing a single chemical modification of IFN-beta1a (alkylation of its only free cysteine residue with N-ethylmaleimide), which causes significant reduction in its antiviral activity. Analysis of IFN-beta1a ionic charge-state distributions unequivocally reveals a significant decrease of conformational stability in the degraded protein, while hydrogen/deuterium exchange measurements provide a clear indication that the higher order structure is affected well beyond the covalent modification site. Importantly, neither technique required that the location or indeed the nature of the chemical modification be known prior to or elucidated in the process of the analysis. In contrast, application of the standard armamentarium of biophysical tools, which are commonly employed for quality control of protein pharmaceuticals, met with very limited success in detection and characterization of conformational changes in the modified IFN-beta1a. This work highlights the role mass spectrometry can and should play in the biopharmaceutical industry beyond the presently assigned task of primary structure analysis.

Modulation of viral replication in macrophages persistently infected with the DA strain of Theiler's murine encephalomyelitis virus.

BACKGROUND: Demyelinating strains of Theiler's murine encephalomyelitis virus (TMEV) such as the DA strain are the causative agents of a persistent infection that induce a multiple sclerosis-like disease in the central nervous system of susceptible mice. Viral persistence, mainly associated with macrophages, is considered to be an important disease determinant that leads to chronic inflammation, demyelination and autoimmunity. In a previous study, we described the establishment of a persistent DA infection in RAW macrophages, which were therefore named DRAW. RESULTS: In the present study we explored the potential of diverse compounds to modulate viral persistence in these DRAW cells. Hemin was found to increase viral yields and to induce cell lysis. Enviroxime and neutralizing anti-TMEV monoclonal antibody were shown to decrease viral yields, whereas interferon-alpha and interferon-gamma completely cleared the persistent infection. We also compared the cytokine pattern secreted by uninfected RAW, DRAW and interferon-cured DRAW macrophages using a cytokine protein array. The chemokine RANTES was markedly upregulated in DRAW cells and restored to a normal expression level after abrogation of the persistent infection with interferon-alpha or interferon-gamma. On the other hand, the chemokine MCP-1 was upregulated in the interferon-cured DRAW cells. CONCLUSION: We have identified several compounds that modulate viral replication in an in vitro model system for TMEV persistence. These compounds now await further testing in an in vivo setting to address fundamental questions regarding persistent viral infection and immunopathogenesis.