Influenza virus (IV) infections are considered to cause severe diseases of the respiratory tract. Beyond mild symptoms, the infection can lead to respiratory distress syndrome and multiple organ ...failure. Occurrence of resistant seasonal and pandemic strains against the currently licensed antiviral medications points to the urgent need for new and amply available anti-influenza drugs. Interestingly, the virus-supportive function of the cellular phosphatidylinositol 3-kinase (PI3K) suggests that this signaling module may be a potential target for antiviral intervention. In the sense of repurposing existing drugs for new indications, we used Pictilisib, a known PI3K inhibitor to investigate its effect on IV infection, in mono-cell-culture studies as well as in a human chip model. Our results indicate that Pictilisib is a potent inhibitor of IV propagation already at early stages of infection. In a murine model of IV pneumonia, the in vitro key findings were verified, showing reduced viral titers as well as inflammatory response in the lung after delivery of Pictilisib. Our data identified Pictilisib as a promising drug candidate for anti-IV therapies that warrant further studying. These results further led to the conclusion that the repurposing of previously approved substances represents a cost-effective and efficient way for development of novel antiviral strategies.
There is agreement that the infectivity assay with the duck hepatitis B virus (DHBV) is a suitable surrogate test to validate disinfectants for hepatitis B virucidal activity. However, since this ...test is not widely used, information is necessary whether disinfectants with limited virucidal activity also inactivate DHBV. In general, disinfectants with limited virucidal activity are used for skin and sensitive surfaces while agents with full activity are more aggressive. The present study compares the activity of five different biocides against DHBV and the classical test virus for limited virucidal activity, the vaccinia virus strain Lister Elstree (VACV) or the modified vaccinia Ankara strain (MVA).
Virucidal assay was performed as suspension test according to the German DVV/RKI guideline. Duck hepatitis B virus obtained from congenitally infected Peking ducks was propagated in primary duck embryonic hepatocytes and was detected by indirect immunofluorescent antigen staining.
The DHBV was inactivated by the use of 40% ethanol within 1-min and 30% isopropanol within 2-min exposure. In comparison, 40% ethanol within 2-min and 40% isopropanol within 1-min exposure were effective against VACV/MVA. These alcohols only have limited virucidal activity, while the following agents have full activity. 0.01% peracetic acid inactivated DHBV within 2 min and a concentration of 0.005% had virucidal efficacy against VACV/MVA within 1 min. After 2-min exposure, 0.05% glutardialdehyde showed a comparable activity against DHBV and VACV/MVA. This is also the case for 0.7% formaldehyde after a contact time of 30 min.
Duck hepatitis B virus is at least as sensitive to limited virucidal activity as VACV/MVA. Peracetic acid is less effective against DHBV, while the alcohols are less effective against VACV/MVA. It can be expected that in absence of more direct tests the results may be extrapolated to HBV.
Pneumonia is the leading cause of hospitalization worldwide. Besides viruses, bacterial co-infections dramatically exacerbate infection. In general, surfactant protein-A (SP-A) represents a first ...line of immune defense. In this study, we analyzed whether influenza A virus (IAV) and/or
(
) infections affect SP-A expression. To closely reflect the situation in the lung, we used a human alveolus-on-a-chip model and a murine pneumonia model. Our results show that
can reduce extracellular levels of SP-A, most likely attributed to bacterial proteases. Mono-epithelial cell culture experiments reveal that the expression of SP-A is not directly affected by IAV or
. Yet, the mRNA expression of SP-A is strongly down-regulated by TNF-α, which is highly produced by professional phagocytes in response to bacterial infection. By using the human alveolus-on-a-chip model, we show that the down-regulation of SP-A is strongly dependent on macrophages. In a murine model of pneumonia, we can confirm that
decreases SP-A levels in vivo. These findings indicate that (I) complex interactions of epithelial and immune cells induce down-regulation of SP-A expression and (II) bacterial mono- and super-infections reduce SP-A expression in the lung, which might contribute to a severe outcome of bacterial pneumonia.
Background The presence of viral genome in the myocardium of patients with dilated cardiomyopathy (DCM) has been suggested as causative for the underlying cardiac disease. Nevertheless, the results ...of present studies are conflicting regarding the natural course of heart diseases associated with detection of viral genome. This study was undertaken to determine if the detection of viral genome in the myocardium of patients with DCM is of functional and prognostic relevance under modern treatment strategies of heart insufficiency. Methods In 197 patients with DCM, left ventricular endomyocardial biopsies were performed. Analysis for genome of adenovirus, enterovirus (EV), and parvovirus B19 as well as enteroviral replication and immunohistology was performed. Results The increase in ejection fraction (EF) was 14.5 ± 12.4% in the EV-positive group compared with 11.1 ± 14.2 in the EV-negative group ( P = not significant NS) after a mean follow-up (FU) of 19.5 and 17.6 months. The increase in EF in the virus-positive group (positive for EV, adenovirus, or parvovirus B19) was 15.3 ± 13.3% compared with 12.3 ± 11.9% in the virus-negative group ( P = NS) after a mean FU of 17.6 and 11.5 months. There was no significant difference in the change of EF between the EV-positive and virus-negative groups. Detection of enteroviral RNA replication (detection of EV minus-strand RNA) did not result in a deterioration of left ventricular function compared with the virus-negative group ( P = NS) after mean FU of 11.2 and 12.0 months. The transplantation-free survival of the patients was not influenced by detection of viral genome. Conclusions Our results favor the view that the presence of viral genome in the myocardium of patients with DCM is of no functional and prognostic relevance.
•Sphingosine-1-phosphate signaling facilitates successful HSV-1 replication.•Reduction of downstream mediator activities decreases HSV-1 production.•Targeting cellular proteins represent efficient ...anti-HSV-1 strategies.
Infections with the herpes simplex virus type 1 (HSV-1) are common and widespread. Most infections remain undetected but severe forms may develop in newborns and in immunocompromised patients. Moreover, HSV-1 might be involved in the pathogenesis of atherosclerosis, which may include viral infection of the endothelium. Antiviral therapy is efficient to treat symptomatic patients. However, an increasing accumulation of resistance-associated mutations has been observed in the viral genome. Thus, new antiviral strategies are focused on host factors. Among others, signaling of bioactive sphingolipids seems to be important in mediating HSV-1 replication. With the present study, regulation and function of sphingosine-1-phosphate (S1P)-based signaling were analyzed in HSV-1-infected human umbilical vein endothelial cells (HUVEC). Our data indicate that viral replication in endothelial cells relies on sphingosine kinase (SK) activity and S1P receptor (S1PR)1,3-5 signaling, which involves the activation of phosphatidylinositol-3-kinase (PI3K) and the small GTPase Ras-related C3 botulinum toxin substrate 1 (Rac-1). Inhibitor- or siRNA-meditated reduction of Rac-1 activity decreased HSV-1 replication. In general, targeting S1P-related signaling may be a successful strategy to establish new anti-HSV-1 therapies.
Up to now, three distinct genotypes, A, B and C, of herpes simplex virus type 1 (HSV-1), based on polymorphisms in the US4 and US7 genes, have been reported. Here, we propose to include an additional ...polymorphism of the US2 gene. The refined genotyping method was validated using 423 clinical isolates from patients with different HSV-1 diseases. The proportions of three US2 genotypes were A, 46.6 %; B, 23.2 %; and C, 30.2 %. Genotype A of US2 and US4/US7 showed a highly significant correlation. In addition, the frequency of genotype A was significantly higher in women than in men with herpes labialis.
The human cytomegalovirus (HCMV) is a common pathogen, which causes severe or even deadly diseases in immunocompromised patients. In addition, congenital HCMV infection represents a major health ...concern affecting especially the lung tissue of the susceptible individuals. Antivirals are a useful strategy to treat HCMV-caused diseases. However, all approved drugs target viral proteins but significant toxicity and an increasing resistance against these compounds have been observed. In infected cells, numerous host molecules have been identified to play important roles during HCMV replication. Among others, HCMV infection depends on the presence of bioactive sphingolipids. In this study, the role of sphingosine-1-phosphate (S1P) signaling in HCMV-infected human embryonal lung fibroblasts (HELF) was analyzed. Viral replication depended on the functional activity of sphingosine kinases (SK). During SK inhibition, addition of extracellular S1P restored HCMV replication. Moreover, neutralization of extracellular S1P by anti-S1P antibodies decreased HCMV replication as well. While the application of FTY720 as an functional antagonist of S1P receptor (S1PR)
1,3−5
signaling did not reduce HCMV replication significantly, JTE-013, an inhibitor of S1PR
2
, decreased viral replication. Furthermore, inhibition of Rac-1 activity reduced HCMV replication, whereas inhibition of the Rac-1 effector protein Rac-1-activated kinase 1 (PAK1) had no influence. In general, targeting S1P-induced pathways, which are essential for a successful HCMV replication, may represent a valuable strategy to develop new antiviral drugs.
While myocardial parvovirus B19 (B19V), aside from enteroviruses (EV) and adenoviruses (ADV), has recently been found often in patients with myocarditis and idiopathic dilated cardiomyopathy (IDC), ...the pathogenetic significance of B19V genomes in those patients has not yet been sufficiently elucidated. In the present study, left ventricular endomyocardial biopsies from 24 patients with left ventricular ejection fraction (LVEF) below 55% due to IDC, and tissue from the right atrial appendage of 10 control patients undergoing bypass surgery with normal LVEF (>55%) were investigated for B19V, ADV, and EV genomes by specific nested polymerase chain reaction (PCR), by real time PCR or by reverse-transcription PCR, respectively. The myocardial tissue samples from the 10 controls were analyzed each in three different virological laboratories for B19V. In the IDC group, the frequency of the myocardial virus genomes found in 54% (13/24) of the patients was as follows: B19V: 50% (12/24), EV: 8% (2/24), including one patient with B19V and EV, and ADV: 0% (0/24). For comparison, the prevalence of B19V genomes was between 30% and 60% in the control group as detected in three different laboratories, but all these control subjects were EV- and ADV-negative. The number of B19V gene copies, however, was very low and similar both in the IDC and control group. In the majority of patients myocardial B19V persistence was associated with a low virus load irrespective of the underlying heart disease so that it may be of no importance in the pathogenesis of IDC. J. Med. Virol. 82:1449-1457, 2010.
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