Andes-virus-induced cytokine storm is partially suppressed by ribavirin

Inhibition of tick-borne encephalitis virus in cell cultures by ribavirin

Tick-borne encephalitis virus (TBEV) belonging to arboviruses is a major member of zoonotic pathogens. TBEV infection causes severe human encephalitis without specific antiviral drugs. Due to its use of antiviral drug against a wide range of viruses, we investigated antiviral effect of ribavirin against TBEV in susceptible human cell lines A549 and SH-SY5Y. Ribavirin displayed minor cytotoxicity on multiple cell lines. Ribavirin obviously impaired TBEV replication and protected the infected cells from cytopathic effect. Importantly, ribavirin markedly inhibited TBEV propagation, as evidenced by impairment of TBEV production and viral RNA replication. Treatment with ribavirin (co-treatment and post-treatment) led to a dose-dependent reduction in TBEV titers as well as the viral RNA levels. Antiviral protein myxovirus resistance A mRNA expression was significantly up-regulated and signal transducer and activator of transcription 3 was activated in TBEV-infected A549 cells upon the ribavirin treatment. Induction of inflammatory cytokine tumor necrosis factor alpha by TBEV was decreased in A549 cells with the treatment of ribavirin, whereas interleukin 1 beta release appeared to be unaffected. These results suggest that ribavirin might represent a promising safe and effective antiviral drug against TBEV.

Andes Virus Genome Mutations That Are Likely Associated with Animal Model Attenuation and Human Person-to-Person Transmission

We performed whole-genome sequencing with bait enrichment techniques to analyze Andes virus (ANDV), a cause of human hantavirus pulmonary syndrome. We used cryopreserved lung tissues from a naturally infected long-tailed colilargo, including early, intermediate, and late cell culture, passages of an ANDV isolate from that animal, and lung tissues from golden hamsters experimentally exposed to that ANDV isolate. The resulting complete genome sequences were subjected to detailed comparative genomic analysis against American orthohantaviruses. We identified four amino acid substitutions related to cell culture adaptation that resulted in attenuation of ANDV in the typically lethal golden hamster animal model of hantavirus pulmonary syndrome. Changes in the ANDV nucleocapsid protein, glycoprotein, and small nonstructural protein open reading frames correlated with mutations typical for ANDV strains associated with increased virulence in the small-animal model. Finally, we identified three amino acid substitutions, two in the small nonstructural protein and one in the glycoprotein, that were only present in the clade of viruses associated with efficient person-to-person transmission. Our results indicate that there are single-nucleotide polymorphisms that could be used to predict strain-specific ANDV virulence and/or transmissibility. IMPORTANCE Several orthohantaviruses cause the zoonotic disease hantavirus pulmonary syndrome (HPS) in the Americas. Among them, HPS caused by Andes virus (ANDV) is of great public health concern because it is associated with the highest case fatality rate (up to 50%). ANDV is also the only orthohantavirus associated with relatively robust evidence of person-to-person transmission. This work reveals nucleotide changes in the ANDV genome that are associated with virulence attenuation in an animal model and increased transmissibility in humans. These findings may pave the way to early severity predictions in future ANDV-caused HPS outbreaks.

Immunogenic Properties of MVs Containing Structural Hantaviral Proteins: An Original Study

Hemorrhagic fever with renal syndrome (HFRS) is an emerging infectious disease that remains a global public health threat. The highest incidence rate is among zoonotic disease cases in Russia. Most cases of HFRS are reported in the Volga region of Russia, which commonly identifies the Puumala virus (PUUV) as a pathogen. HFRS management is especially challenging due to the lack of specific treatments and vaccines. This study aims to develop new approaches for HFRS prevention. Our goal is to test the efficacy of microvesicles (MVs) as PUUV nucleocapsid (N) and glycoproteins (Gn/Gc) delivery vehicles. Our findings show that MVs could deliver the PUUV N and Gn/Gc proteins in vitro. We have also demonstrated that MVs loaded with PUUV proteins could elicit a specific humoral and cellular immune response in vivo. These data suggest that an MV-based vaccine could control HFRS.

Comparison of transcriptional responses between pathogenic and nonpathogenic hantavirus infections in Syrian hamsters using NanoString

BACKGROUND

Syrian hamsters infected with Andes virus (ANDV) develop a disease that recapitulates many of the salient features of human hantavirus pulmonary syndrome (HPS), including lethality. Infection of hamsters with Hantaan virus (HTNV) results in an asymptomatic, disseminated infection. In order to explore this dichotomy, we examined the transcriptome of ANDV- and HTNV-infected hamsters.

RESULTS

Using NanoString technology, we examined kinetic transcriptional responses in whole blood collected from ANDV- and HTNV-infected hamsters. Of the 770 genes analyzed, key differences were noted in the kinetics of type I interferon sensing and signaling responses, complement activation, and apoptosis pathways between ANDV- and HTNV-infected hamsters.

CONCLUSIONS

Delayed activation of type I interferon responses in ANDV-infected hamsters represents a potential mechanism that ANDV uses to subvert host immune responses and enhance disease. This is the first genome-wide analysis of hantavirus-infected hamsters and provides insight into potential avenues for therapeutics to hantavirus disease.

Immunomodulatory and anti-cytokine therapeutic potential of curcumin and its derivatives for treating COVID-19 - a computational modeling

The unavailability of vaccine and medicines raised serious issues during COVID-19 pandemic and peoples from different parts of world relied on traditional medicine for their immediate recovery from COVID-19 and it found effective also. The current research aims to target COVID-19 immunological human host receptors i.e. angiotensin-converting enzyme (ACE)-2, interleukin (IL)-1β, IL-6, tumor necrosis factor-alpha (TNF-α) and protease-activated receptor (PAR)-1 using curcumin derivatives to prevent viral infection and control overproduction of early clinical responses of COVID-19. Targeting these host proteins will mitigate the infection and will filter out many complications caused by these proteins in COVID-19 patients. It is proven through computer-aided computational modeling approaches, total 30 compounds of curcumin and its derivatives were chosen. Drug-likeness parameters were calculated for curcumin and its derivatives and 20 curcumin analogs were selected for docking analysis. From docking analysis of 20 curcumin analogs against five chosen human host receptor targets reveals 11 curcumin analogs possess least binding affinity and best interaction at active sites subjected to absorption, distribution, metabolism, excretion (ADME) analysis. Density functional theory (DFT) analysis of five final shortlisted curcumin derivatives was done to show least binding affinity toward chosen host target protein. Molecular dynamics simulation (MDS) was performed to observe behavior and interaction of potential drug hydrazinocurcumin against target proteins ACE-2 and PAR-1. It was performed at 100 nanoseconds and showed satisfactory results. Finally, our investigation reveals that hydrazinocurcumin possesses immunomodulatory and anti-cytokine therapeutic potential against COVID-19 and it can act as COVID-19 warrior drug molecule and promising choice of drug for COVID-19 treatment, however, it needs further in vivo clinical evaluation to commercialize as COVID-19 drug.Communicated by Ramaswamy H. Sarma.

Hantavirus Cardiopulmonary Syndrome Due to Imported Andes Hantavirus Infection in Switzerland: A Multidisciplinary Challenge, Two Cases and a Literature Review

Two travellers returning from South America were diagnosed with Andes hantavirus infection, the only member of the Hantaviridae family known to be transmitted from person to person. We describe the clinical course and therapeutic and infection control measures. While both patients showed high viral load (VL) and shedding over several months, 1 patient recovered within 1 week from severe respiratory illness that required noninvasive ventilation, whereas the second patient developed severe hantavirus cardiopulmonary syndrome that required extracorporeal membrane oxygenation for 27 days. The clinical course in the latter patient was complicated by severe disseminated intravascular coagulopathy with diffuse hemorrhage that necessitated mass transfusions, as well as by multiple organ failure, including the need for renal replacement therapy. Results of VL in blood, respiratory secretions, and semen for the first 9 months of follow-up are reported. To our knowledge, these are the first cases of Andes hantavirus infection detected in Europe.

Hantavirus-induced disruption of the endothelial barrier: neutrophils are on the payroll

Viral hemorrhagic fever caused by hantaviruses is an emerging infectious disease for which suitable treatments are not available. In order to improve this situation a better understanding of hantaviral pathogenesis is urgently required. Hantaviruses infect endothelial cell layers in vitro without causing any cytopathogenic effect and without increasing permeability. This implies that the mechanisms underlying vascular hyperpermeability in hantavirus-associated disease are more complex and that immune mechanisms play an important role. In this review we highlight the latest developments in hantavirus-induced immunopathogenesis. A possible contribution of neutrophils has been neglected so far. For this reason, we place special emphasis on the pathogenic role of neutrophils in disrupting the endothelial barrier.

The fundamental role of endothelial cells in hantavirus pathogenesis

Hantavirus, a genus of rodent- and insectivore-borne viruses in the family Bunyaviridae, is a group of emerging zoonotic pathogens. Hantaviruses cause hemorrhagic fever with renal syndrome and hantavirus cardiopulmonary syndrome in man, often with severe consequences. Vascular leakage is evident in severe hantavirus infections, and increased permeability contributes to the pathogenesis. This review summarizes the current knowledge on hantavirus interactions with hematopoietic and endothelial cells, and their effects on the increased vascular permeability.

Effectiveness of the ribavirin in treatment of hantavirus infections in the Americas and Eurasia: a meta-analysis

Hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS) are transmitted to humans through infection with the old- and new-world hantaviruses, respectively. Together these diseases affect tens of thousands of people every year, and no specific treatment is available. To investigate whether ribavirin treatment for hantaviruses infections decreases disease severity, we conducted a meta-analysis involving human and animal studies. After defining the research protocol and criteria for inclusion/exclusion, we identified seven studies. We found that in groups with HPS who were treated with ribavirin, there was no significant reduction in mortality (RR 0.99, 95 % CI 0.60-1.61, I(2) = 0 %). On the other hand, for animal group with HPS-like disease, there was significant increase in survival (RR 0.05, 95 % CI 0.01-0.34, I(2) = 0 %). For animal group infected with the old-world hantaviruses, treated with ribavirin, there was a statistically significant increase in survival (RR 0.56, 95 % CI 0.42-0.76, I(2) = 64 %). Similarly, for humans with HFRS treated, there was increase in survival (RR 0.28, 95 % CI 0.08-1), although only a study exist. Our meta-analysis provides data that should be interpreted with caution, partly due to the limited number of studies available. Additionally, the results of the application of ribavirin in the population with HPS could not be determined, particularly in patients in the end stage of this disease.