scholarly journals Temporal Analysis of Andes Virus and Sin Nombre Virus Infections of Syrian Hamsters

2007 ◽  
Vol 81 (14) ◽  
pp. 7449-7462 ◽  
Author(s):  
Victoria Wahl-Jensen ◽  
Jennifer Chapman ◽  
Ludmila Asher ◽  
Robert Fisher ◽  
Michael Zimmerman ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Disease Onset ◽  
Treatment Strategies ◽  
Hemorrhagic Fever ◽  
Temporal Analysis ◽  
Sin Nombre Virus ◽  
Virus Infections ◽  
Syrian Hamsters ◽  
Time To Death ◽  
Andes Virus

ABSTRACT Andes virus (ANDV) and Sin Nombre virus (SNV) are rodent-borne hantaviruses that cause a highly lethal hemorrhagic fever in humans known as hantavirus pulmonary syndrome (HPS). There are no vaccines or specific drugs to prevent or treat HPS, and the pathogenesis is not understood. Syrian hamsters infected with ANDV, but not SNV, develop a highly lethal disease that closely resembles HPS in humans. Here, we performed a temporal pathogenesis study comparing ANDV and SNV infections in hamsters. SNV was nonpathogenic and viremia was not detected despite the fact that all animals were infected. ANDV was uniformly lethal with a mean time to death of 11 days. The first pathology detected was lymphocyte apoptosis starting on day 4. Animals were viremic and viral antigen was first observed in multiple organs by days 6 and 8, respectively. Levels of infectious virus in the blood increased 4 to 5 logs between days 6 and 8. Pulmonary edema was first detected ultrastructurally on day 6. Ultrastructural analysis of lung tissues revealed the presence of large inclusion bodies and substantial numbers of vacuoles within infected endothelial cells. Paraendothelial gaps were not observed, suggesting that fluid leakage was transcellular and directly attributable to infecting virus. Taken together, these data imply that HPS treatment strategies aimed at preventing virus replication and dissemination will have the greatest probability of success if administered before the viremic phase; however, because vascular leakage is associated with infected endothelial cells, a therapeutic strategy targeting viral replication might be effective even at later times (e.g., after disease onset).

A key role for Toll-like receptor-3 in disrupting the hemostasis balance on endothelial cells

Blood ◽  
2009 ◽  
Vol 113 (3) ◽  
pp. 714-722 ◽  
Author(s):  
Aya Shibamiya ◽  
Karin Hersemeyer ◽  
Thomas Schmidt Wöll ◽  
Daniel Sedding ◽  
Jan-Marcus Daniel ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tissue Factor ◽  
Hemorrhagic Fever ◽  
Poly I:C ◽  
Toll Like Receptor ◽  
Virus Infections ◽  
Direct Stimulation ◽  
Viral Dsrna ◽  
Stimulation Of

AbstractVarious virus infections cause dysfunctional hemostasis and in some instances lead to the development of viral hemorrhagic fever syndrome. How do diverse viruses induce the expression of tissue factor on vascular cells? We hypothesize that a direct stimulation of pattern recognition receptors (PRR) by viral nucleic acids may be the key. Double-stranded RNA (dsRNA) is produced by many viruses and is recognized by various PRR, including Toll-like receptor-3 (TLR3). We have investigated whether poly I:C, a model for viral dsRNA, can influence cellular hemostasis. Poly I:C could up-regulate tissue factor and down-regulate thrombomodulin expression on endothelial cells but not on monocytes. The response to poly I:C was diminished upon small interfering RNA (siRNA)–mediated inhibition of TLR3, but not other PRR. In vivo, application of poly I:C induced similar changes in the aortic endothelium of mice as determined by enface microscopy. D-dimer, a circulating marker for enhanced coagulation and fibrinolysis, and tissue fibrin deposition was elevated. All the hemostasis-related responses to poly I:C, but not cytokine secretion, were blunted in TLR3−/− mice. Hence, the activation of TLR3 can induce the procoagulant state in the endothelium, and this could be relevant for understanding the mechanisms of viral stimulation of hemostasis.

scholarly journals Innate immune responses elicited by Sin Nombre virus or type I IFN agonists protect hamsters from lethal Andes virus infections

2018 ◽  
Vol 99 (10) ◽  
pp. 1359-1366 ◽  
Author(s):  
Rebecca L. Brocato ◽  
Victoria Wahl ◽  
Christopher D. Hammerbeck ◽  
Matthew D. Josleyn ◽  
Anita K. McElroy ◽  
...  
Keyword(s):  
Immune Responses ◽  
Innate Immune ◽  
Sin Nombre Virus ◽  
Type I ◽  
Type I Ifn ◽  
Innate Immune Responses ◽  
Virus Infections ◽  
Andes Virus

scholarly journals Andes and Prospect Hill Hantaviruses Differ in Early Induction of Interferon although Both Can Downregulate Interferon Signaling

2007 ◽  
Vol 81 (6) ◽  
pp. 2769-2776 ◽  
Author(s):  
Christina F. Spiropoulou ◽  
César G. Albariño ◽  
Thomas G. Ksiazek ◽  
Pierre E. Rollin
Keyword(s):  
Endothelial Cells ◽  
Nuclear Translocation ◽  
Sin Nombre Virus ◽  
Hantavirus Infection ◽  
Interferon Signaling ◽  
Interferon Induction ◽  
Andes Virus ◽  
Main Target ◽  
Infected Cells ◽  
Lung Endothelial Cells

ABSTRACT Hantavirus pulmonary syndrome (HPS) is a severe respiratory disease which is thought to result from a dysregulated immune response to infection with pathogenic hantaviruses, such as Sin Nombre virus or Andes virus (ANDV). Other New World hantaviruses, such as Prospect Hill virus (PHV), have not been associated with human disease. Activation of an antiviral state and cell signaling in response to hantavirus infection were examined using human primary lung endothelial cells, the main target cell infected in HPS patients. PHV, but not ANDV, was found to induce a robust beta interferon (IFN-β) response early after infection of primary lung endothelial cells. The level of IFN induction correlated with IFN regulatory factor 3 (IRF-3) activation, in that IRF-3 dimerization and nuclear translocation were detected in PHV but not ANDV infection. In addition, phosphorylated Stat-1/2 levels were significantly lower in the ANDV-infected cells relative to PHV. Presumably, this reflects the lower level of IRF-3 activation and initial IFN induced by ANDV relative to PHV. To determine whether, in addition, ANDV interference with IFN signaling also contributed to the low Stat-1/2 activation seen in ANDV infection, the levels of exogenous IFN-β-induced Stat-1/2 activation detectable in uninfected versus ANDV- or PHV-infected Vero-E6 cells were examined. Surprisingly, both viruses were found to downregulate IFN-induced Stat-1/2 activation. Analysis of cells transiently expressing only ANDV or PHV glycoproteins implicated these proteins in this downregulation. In conclusion, while both viruses can interfere with IFN signaling, there is a major difference in the initial interferon induction via IRF-3 activation between ANDV and PHV in infected primary endothelial cells, and this correlates with the reported differences in pathogenicity of these viruses.

scholarly journals Vascular Inflammation Is Associated with Loss of Aquaporin 1 Expression on Endothelial Cells and Increased Fluid Leakage in SARS-CoV-2 Infected Golden Syrian Hamsters

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 639
Author(s):  
Lisa Allnoch ◽  
Georg Beythien ◽  
Eva Leitzen ◽  
Kathrin Becker ◽  
Franz-Josef Kaup ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Inflammation ◽  
Intercellular Junctions ◽  
Edema Formation ◽  
Vascular Integrity ◽  
Syrian Hamsters ◽  
Aquaporin 1 ◽  
Vascular Walls ◽  
Transmission Electron ◽  
Mock Infection

Vascular changes represent a characteristic feature of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection leading to a breakdown of the vascular barrier and subsequent edema formation. The aim of this study was to provide a detailed characterization of the vascular alterations during SARS-CoV-2 infection and to evaluate the impaired vascular integrity. Groups of ten golden Syrian hamsters were infected intranasally with SARS-CoV-2 or phosphate-buffered saline (mock infection). Necropsies were performed at 1, 3, 6, and 14 days post-infection (dpi). Lung samples were investigated using hematoxylin and eosin, alcian blue, immunohistochemistry targeting aquaporin 1, CD3, CD204, CD31, laminin, myeloperoxidase, SARS-CoV-2 nucleoprotein, and transmission electron microscopy. SARS-CoV-2 infected animals showed endothelial hypertrophy, endothelialitis, and vasculitis. Inflammation mainly consisted of macrophages and lower numbers of T-lymphocytes and neutrophils/heterophils infiltrating the vascular walls as well as the perivascular region at 3 and 6 dpi. Affected vessels showed edema formation in association with loss of aquaporin 1 on endothelial cells. In addition, an ultrastructural investigation revealed disruption of the endothelium. Summarized, the presented findings indicate that loss of aquaporin 1 entails the loss of intercellular junctions resulting in paracellular leakage of edema as a key pathogenic mechanism in SARS-CoV-2 triggered pulmonary lesions.

scholarly journals Exacerbation of Influenza Virus Infections in Mice by Intranasal Treatments and Implications for Evaluation of Antiviral Drugs

2012 ◽  
Vol 56 (12) ◽  
pp. 6328-6333 ◽  
Author(s):  
Donald F. Smee ◽  
Mark von Itzstein ◽  
Beenu Bhatt ◽  
E. Bart Tarbet
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
H1n1 Virus ◽  
Antiviral Agent ◽  
Virus Production ◽  
Lung Pathology ◽  
Virus Infections ◽  
Challenge Dose ◽  
Virus Challenge ◽  
Time To Death

ABSTRACTCompounds lacking oral activity may be delivered intranasally to treat influenza virus infections in mice. However, intranasal treatments greatly enhance the virulence of such virus infections. This can be partially compensated for by giving reduced virus challenge doses. These can be 100- to 1,000-fold lower than infections without such treatment and still cause equivalent mortality. We found that intranasal liquid treatments facilitate virus production (probably through enhanced virus spread) and that lung pneumonia was delayed by only 2 days relative to a 1,000-fold higher virus challenge dose not accompanied by intranasal treatments. In one study, zanamivir was 90 to 100% effective at 10 mg/kg/day by oral, intraperitoneal, and intramuscular routes against influenza A/California/04/2009 (H1N1) virus in mice. However, the same compound administered intranasally at 20 mg/kg/day for 5 days gave no protection from death although the time to death was significantly delayed. A related compound, Neu5Ac2en (N-acetyl-2,3-dehydro-2-deoxyneuraminic acid), was ineffective at 100 mg/kg/day. Intranasal zanamivir and Neu5Ac2en were 70 to 100% protective against influenza A/NWS/33 (H1N1) virus infections at 0.1 to 10 and 30 to 100 mg/kg/day, respectively. Somewhat more difficult to treat was A/Victoria/3/75 virus that required 10 mg/kg/day of zanamivir to achieve full protection. These results illustrate that treatment of influenza virus infections by the intranasal route requires consideration of both virus challenge dose and virus strain in order to avoid compromising the effectiveness of a potentially useful antiviral agent. In addition, the intranasal treatments were shown to facilitate virus replication and promote lung pathology.

scholarly journals Pathogen Dose in Animal Models of Hemorrhagic Fever Virus Infections and the Potential Impact on Studies of the Immune Response

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 275
Author(s):  
Bryce M. Warner
Keyword(s):  
Immune Response ◽  
Animal Models ◽  
Hemorrhagic Fever ◽  
Virus Infections ◽  
Critical Determinant ◽  
Animal Models Of Disease ◽  
Hemorrhagic Fever Virus ◽  
Immune Correlates ◽  
Clinical Drug Development ◽  
Wide Range

Viral hemorrhagic fever viruses come from a wide range of virus families and are a significant cause of morbidity and mortality worldwide each year. Animal models of infection with a number of these viruses have contributed to our knowledge of their pathogenesis and have been crucial for the development of therapeutics and vaccines that have been approved for human use. Most of these models use artificially high doses of virus, ensuring lethality in pre-clinical drug development studies. However, this can have a significant effect on the immune response generated. Here I discuss how the dose of antigen or pathogen is a critical determinant of immune responses and suggest that the current study of viruses in animal models should take this into account when developing and studying animal models of disease. This can have implications for determination of immune correlates of protection against disease as well as informing relevant vaccination and therapeutic strategies.

scholarly journals Two Complex, Adenovirus-Based Vaccines That Together Induce Immune Responses to All Four Dengue Virus Serotypes

2006 ◽  
Vol 14 (2) ◽  
pp. 182-189 ◽  
Author(s):  
David H. Holman ◽  
Danher Wang ◽  
Kanakatte Raviprakash ◽  
Nicholas U. Raja ◽  
Min Luo ◽  
...  
Keyword(s):  
Immune Responses ◽  
Dengue Virus ◽  
Vaccine Development ◽  
De Novo ◽  
Natural Infection ◽  
Hemorrhagic Fever ◽  
Virus Infections ◽  
Dengue Vaccine ◽  
Membrane Antigens ◽  
Dengue Virus Serotypes

ABSTRACT Dengue virus infections can cause hemorrhagic fever, shock, encephalitis, and even death. Worldwide, approximately 2.5 billion people live in dengue-infested regions with about 100 million new cases each year, although many of these infections are believed to be silent. There are four antigenically distinct serotypes of dengue virus; thus, immunity from one serotype will not cross-protect from infection with the other three. The difficulties that hamper vaccine development include requirements of the natural conformation of the envelope glycoprotein to induce neutralizing immune responses and the necessity of presenting antigens of all four serotypes. Currently, the only way to meet these requirements is to use a mixture of four serotypes of live attenuated dengue viruses, but safety remains a major problem. In this study, we have developed the basis for a tetravalent dengue vaccine using a novel complex adenovirus platform that is capable of expressing multiple antigens de novo. This dengue vaccine is constructed as a pair of vectors that each expresses the premembrane and envelope genes of two different dengue virus serotypes. Upon vaccination, the vaccine expressed high levels of the dengue virus antigens in cells to mimic a natural infection and induced both humoral and cellular immune responses against multiple serotypes of dengue virus in an animal model. Further analyses show the humoral responses were indeed neutralizing against all four serotypes. Our studies demonstrate the concept of mimicking infections to induce immune responses by synthesizing dengue virus membrane antigens de novo and the feasibility of developing an effective tetravalent dengue vaccine by vector-mediated expression of glycoproteins of the four serotypes.

Characterization of dengue virus infections in a sample of patients suggests unique clinical, immunological, and virological profiles that impact on the diagnosis of dengue and dengue hemorrhagic fever

2016 ◽  
Vol 88 (10) ◽  
pp. 1703-1710 ◽  
Author(s):  
Thamarasi Senaratne ◽  
Harith Wimalaratne ◽  
D. G. S. Alahakoon ◽  
Nirmali Gunawardane ◽  
Jillian Carr ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Dengue Hemorrhagic Fever ◽  
Hemorrhagic Fever ◽  
Virus Infections

Treatment strategies for protein-losing enteropathy in Fontan-palliated patients

2020 ◽  
Vol 30 (5) ◽  
pp. 698-709
Author(s):  
Anastasia Schleiger ◽  
Stanislav Ovroutski ◽  
Björn Peters ◽  
Stephan Schubert ◽  
Joachim Photiadis ◽  
...  
Keyword(s):  
Cardiac Transplantation ◽  
Fontan Procedure ◽  
Disease Onset ◽  
Treatment Strategies ◽  
Individual Treatment ◽  
Interventional Treatment ◽  
Vasodilator Therapy ◽  
Protein Losing Enteropathy ◽  
Pulmonary Vasodilator

AbstractObjective:Protein-losing enteropathy is an infrequent but severe condition occurring after Fontan procedure. The multifactorial pathogenesis remains unclear and no single proposed treatment strategy has proven universally successful. Therefore, we sought to describe different treatment strategies and their effect on clinical outcome and mortality.Material and Methods:We performed a retrospective observational study. From the total cohort of 439 Fontan patients treated in our institution during the study period 1986–2019, 30 patients (6.8%) with protein-losing enteropathy were identified. Perioperative, clinical, echocardiographic, laboratory, and invasive haemodynamic findings and treatment details were analysed.Results:Median follow-up after disease onset was 13.1 years [interquartile range 10.6]. Twenty-five patients received surgical or interventional treatment for haemodynamic restrictions. Medical treatment, predominantly pulmonary vasodilator and/or systemic anti-inflammatory therapy with budesonide, was initiated in 28 patients. In 15 patients, a stable remission could be achieved by medical or surgical procedures (n = 3 each), by combined multimodal therapy (n = 8), or ultimately by cardiac transplantation (n = 1). Phrenic palsy, bradyarrhythmia, Fontan pathway stenosis, and absence of a fenestration were significantly associated with development of protein-losing enteropathy (p = 0.001–0.48). Ten patients (33.3%) died during follow-up; 5-year survival estimate was 96.1%. In unadjusted analysis, medical therapy with budesonide and pulmonary vasodilator therapy in combination was associated with improved survival.Conclusions:Protein-losing enteropathy is a serious condition limiting survival after the Fontan procedure. Comprehensive assessment and individual treatment strategies are mandatory to achieve best possible outcome. Nevertheless, relapse is frequent and long-term mortality substantial. Cardiac transplantation should be considered early as treatment option.

Sign in / Sign up

Export Citation Format

Share Document