scholarly journals The Characterization of chIFITMs in Avian Coronavirus Infection In Vivo, Ex Vivo and In Vitro

Genes ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 918
Author(s):  
Angela Steyn ◽  
Sarah Keep ◽  
Erica Bickerton ◽  
Mark Fife
Keyword(s):  
Post Infection ◽  
Viral Infections ◽  
Ex Vivo ◽  
Large Family ◽  
Respiratory Pathogen ◽  
Restriction Factors ◽  
Respiratory Illnesses ◽  
Bird Mortality

The coronaviruses are a large family of enveloped RNA viruses that commonly cause gastrointestinal or respiratory illnesses in the infected host. Avian coronavirus infectious bronchitis virus (IBV) is a highly contagious respiratory pathogen of chickens that can affect the kidneys and reproductive systems resulting in bird mortality and decreased reproductivity. The interferon-inducible transmembrane (IFITM) proteins are activated in response to viral infections and represent a class of cellular restriction factors that restrict the replication of many viral pathogens. Here, we characterize the relative mRNA expression of the chicken IFITM genes in response to IBV infection, in vivo, ex vivo and in vitro using the pathogenic M41-CK strain, the nephropathogenic QX strain and the nonpathogenic Beaudette strain. In vivo we demonstrate a significant upregulation of chIFITM1, 2, 3 and 5 in M41-CK- and QX-infected trachea two days post-infection. In vitro infection with Beaudette, M41-CK and QX results in a significant upregulation of chIFITM1, 2 and 3 at 24 h post-infection. We confirmed a differential innate response following infection with distinct IBV strains and believe that our data provide new insights into the possible role of chIFITMs in early IBV infection.

scholarly journals Non-Toxic Virucidal Macromolecules Show High Efficacy Against Influenza Virus Ex Vivo and In Vivo

2020 ◽  
Author(s):  
Ozgun Kocabiyik ◽  
Valeria Cagno ◽  
Paulo Jacob Silva ◽  
Yong Zhu ◽  
Laura Sedano ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Viral Infections ◽  
Ex Vivo ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
New Class ◽  
Influenza Strain ◽  
Low Toxicity

AbstractInfluenza is one of the most widespread viral infections worldwide and represents a major public health problem. The risk that one of the next pandemics is caused by an influenza strain is very high. It is very important to develop broad-spectrum influenza antivirals to be ready for any possible vaccine shortcomings. Anti-influenza drugs are available but they are far from ideal. Arguably, an ideal antiviral should target conserved viral domains and be virucidal, i.e. irreversibly inhibit viral infectivity. Here, we describe a new class of broad-spectrum anti-influenza macromolecules that meets these criteria and displays exceedingly low toxicity. These compounds are based on a cyclodextrin core modified on its primary face with long hydrophobic linkers terminated in 6’sialyl-N-acetyllactosamine (6’SLN) or 3’SLN. SLN enables nanomolar inhibition of the viruses while the hydrophobic linkers confer irreversibility to the inhibition. The combination of these two properties allows for efficacy in vitro against several human or avian influenza strains, as well as against a 2009 pandemic influenza strain ex vivo. Importantly, we show that, in mice, the compounds provide therapeutic efficacy when administered 24h post-infection allowing 90% survival as opposed to no survival for the placebo and oseltamivir..

Dendritic Cells Efficiently Induce Protective Antiviral Immunity

1998 ◽  
Vol 72 (5) ◽  
pp. 3812-3818 ◽  
Author(s):  
Burkhard Ludewig ◽  
Stephan Ehl ◽  
Urs Karrer ◽  
Bernhard Odermatt ◽  
Hans Hengartner ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
High Speed ◽  
Viral Infections ◽  
Ex Vivo ◽  
Antiviral Immunity ◽  
Recombinant Vaccinia Virus ◽  
Challenge Infection ◽  
Antiviral Immune Response

ABSTRACT Cytotoxic T lymphocytes (CTL) are essential for effective immunity to various viral infections. Because of the high speed of viral replication, control of viral infections imposes demanding functional and qualitative requirements on protective T-cell responses. Dendritic cells (DC) have been shown to efficiently acquire, transport, and present antigens to naive CTL in vitro and in vivo. In this study, we assessed the potential of DC, either pulsed with the lymphocytic choriomeningitis virus (LCMV)-specific peptide GP33-41 or constitutively expressing the respective epitope, to induce LCMV-specific antiviral immunity in vivo. Comparing different application routes, we found that only 100 to 1,000 DC had to reach the spleen to achieve protective levels of CTL activation. The DC-induced antiviral immune response developed rapidly and was long lasting. Already at day 2 after a single intravenous immunization with high doses of DC (1 × 105 to 5 × 105), mice were fully protected against LCMV challenge infection, and direct ex vivo cytotoxicity was detectable at day 4 after DC immunization. At day 60, mice were still protected against LCMV challenge infection. Importantly, priming with DC also conferred protection against infections in which the homing of CTL into peripheral organs is essential: DC-immunized mice rapidly cleared an infection with recombinant vaccinia virus-LCMV from the ovaries and eliminated LCMV from the brain, thereby avoiding lethal choriomeningitis. A comparison of DC constitutively expressing the GP33-41 epitope with exogenously peptide-pulsed DC showed that in vivo CTL priming with peptide-loaded DC is not limited by turnover of peptide-major histocompatibility complex class I complexes. We conclude that the priming of antiviral CTL responses with DC is highly efficient, rapid, and long lasting. Therefore, the use of DC should be considered as an efficient means of immunization for antiviral vaccination strategies.

scholarly journals Carrageenans as Broad-Spectrum Microbicides: Current Status and Challenges

Marine Drugs ◽  
2020 ◽  
Vol 18 (9) ◽  
pp. 435
Author(s):  
Choongho Lee
Keyword(s):  
Broad Spectrum ◽  
Red Algae ◽  
Viral Infections ◽  
Ex Vivo ◽  
Antimicrobial Activities ◽  
Current Status ◽  
Sulfated Polysaccharides ◽  
Future Research

Different kinds of red algae are enriched with chemically diverse carbohydrates. In particular, a group of sulfated polysaccharides, which were isolated from the cell walls of red algae, gained a large amount of attention due to their broad-spectrum antimicrobial activities. Within that group, carrageenans (CGs) were expected to be the first clinically applicable microbicides that could prevent various viral infections due to their superior antiviral potency and desirable safety profiles in subclinical studies. However, their anticipated beneficial effects could not be validated in human studies. To assess the value of a second attempt at pharmacologically developing CGs as a new class of preventive microbicides, all preclinical and clinical development processes of CG-based microbicides need to be thoroughly re-evaluated. In this review, the in vitro toxicities; in vivo safety profiles; and in vitro, ex vivo, and in vivo antiviral activities of CGs are summarized according to the study volume of their target viruses, which include human immunodeficiency virus, herpesviruses, respiratory viruses, human papillomavirus, dengue virus, and other viruses along with a description of their antiviral modes of action and development of antiviral resistance. This evaluation of the strengths and weaknesses of CGs will help provide future research directions that may lead to the successful development of CG-based antimicrobial prophylactics.

scholarly journals Identification of Novel Host Factors via Conserved Domain Search: Cns1 Cochaperone Is a Novel Restriction Factor of Tombusvirus Replication in Yeast

2013 ◽  
Vol 87 (23) ◽  
pp. 12600-12610 ◽  
Author(s):  
Jing-Yi Lin ◽  
Peter D. Nagy
Keyword(s):  
Viral Infections ◽  
Large Family ◽  
Cellular Proteins ◽  
Temperature Sensitive ◽  
Restriction Factors ◽  
Strong Inhibitor ◽  
Replication Assay ◽  
Inhibitory Function ◽  
Novel Host

A large number of host-encoded proteins affect the replication of plus-stranded RNA viruses by acting as susceptibility factors. Many other cellular proteins are known to function as restriction factors of viral infections. Previous studies with tomato bushy stunt tombusvirus (TBSV) in a yeast model host have revealed the inhibitory function of TPR (tetratricopeptide repeat) domain-containing cyclophilins, which are members of the large family of host prolyl isomerases, in TBSV replication. In this paper, we tested additional TPR-containing yeast proteins in a cell-free TBSV replication assay and identified the Cns1p cochaperone for heat shock protein 70 (Hsp70) and Hsp90 chaperones as a strong inhibitor of TBSV replication. Cns1p interacted with the viral replication proteins and inhibited the assembly of the viral replicase complex and viral RNA synthesisin vitro. Overexpression of Cns1p inhibited TBSV replication in yeast. The use of a temperature-sensitive (TS) mutant of Cns1p in yeast revealed that at a semipermissive temperature, TS Cns1p could not inhibit TBSV replication. Interestingly, Cns1p and the TPR-containing Cpr7p cyclophilin have similar inhibitory functions during TBSV replication, although some of the details of their viral restriction mechanisms are different. Our observations indicate that TPR-containing cellular proteins could act as virus restriction factors.

scholarly journals Bi-reporter vaccinia virus for tracking viral infections in vitro and in vivo

2021 ◽  
Author(s):  
Kevin Chiem ◽  
María Lorenzo ◽  
Javier Rangel-Moreno ◽  
Maria de la Luz Garcia-Hernandez ◽  
Jun-Gyu Park ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Viral Infections ◽  
Viral Vector ◽  
Ex Vivo ◽  
Reporter Genes ◽  
Luciferase Reporter ◽  
Recombinant Viruses ◽  
Antibody Staining

Recombinant viruses expressing reporter genes allow visualization and quantification of viral infections and can be used as valid surrogates to identify the presence of the virus in infected cells and animal models. However, one of the limitations of recombinant viruses expressing reporter genes is the use of either fluorescent or luciferase proteins that are used alternatively for different purposes. Vaccinia virus (VV) is widely used as a viral vector, including recombinant (r)VV singly expressing either fluorescent or luciferase reporter genes that are useful for specific purposes. In this report, we engineered two novel rVV stably expressing both fluorescent (Scarlet or GFP) and luciferase (Nluc) reporter genes from different loci in the viral genome. In vitro, these bi-reporter expressing rVV have similar growth kinetics and plaque phenotype than those of the parental WR VV isolate. In vivo, rVV Nluc/Scarlet and rVV Nluc/GFP effectively infected mice and were easily detected using in vivo imaging systems (IVIS) and ex vivo in the lungs from infected mice. We used these bi-reporter expressing rVV to assess viral pathogenesis, infiltration of immune cells in the lungs, and to directly identify the different subsets of cells infected by VV in the absence of antibody staining. Collectively, these rVV expressing two reporter genes open the feasibility to study the biology of viral infections in vitro and in vivo, including host-pathogen interactions and dynamics or tropism of viral infections. Moreover, they represent an excellent approach for the discovery of new prophylactics and/or therapeutics for the treatment of poxvirus infections.

scholarly journals Ethnomedicinal Use, Phytochemistry, and Pharmacology of Xylocarpus granatum J. Koenig

2021 ◽  
Vol 2021 ◽  
pp. 1-16 ◽  
Author(s):  
Dipta Dey ◽  
Cristina Quispe ◽  
Rajib Hossain ◽  
Divya Jain ◽  
Rasel Ahmed Khan ◽  
...  
Keyword(s):  
Viral Infections ◽  
Ex Vivo ◽  
Medical Science ◽  
In Vivo Studies ◽  
Human Beings ◽  
Mangrove Plant ◽  
Xylocarpus Granatum ◽  
Wide Range

The mangrove plants are the potential sources of foods and remedies for people living in the forests and nearby communities. Xylocarpus granatum J. Koenig is traditionally used to treat various diseases including diarrhea, cholera, dysentery, fever, malaria, and viral infections, among others. To summarize critically the taxonomy, ethnomedicinal, phytochemistry, and pharmacological activities of X. granatum, information was collected from different databases. An up-to-date search (till June 2020) was carried out with the help of various scientific web resources from databases such as PubMed, Science Direct, Google Scholar, and various patent offices (e.g., WIPO, CIPO, and USPTO) using the keywords “Xylocarpus granatum” and then paired with ethnomedicinal use and phytochemical, phytochemistry, and pharmacological activity (in vitro, ex vivo, and in vivo studies). Findings revealed that seeds, fruits, stem bark, leaf, and twigs of X. granatum exhibited a wide range of key phytochemicals including limonoids, phragmalin, limonoid-based alkaloids, mexicanolides, protolimonoids, flavonols, and lactones. The plant possessed potent antioxidant, anticancer, antidiabetic, antimicrobial, antimalarial, antifeedant, and neuroprotective activities. No clinical studies have been reported in the databases. Ethnomedicinal assessment indicated the application of X. granatum in various fields of medical science specially to treat various human ailments, and this was attributed to the presence of enormous alkaloids as confirmed by pharmacological studies. However, to understand the mechanism of action in-depth studies are required. In view of these findings, more research is necessary to explore and characterize the chemical compounds and toxicological aspects of this medicinal mangrove plant. Overall, it can be stated that X. granatum may be one of the hopeful medicinal herbs for the treatment of various diseases in human beings.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Significance of Platelet β-Adrenoceptors for Platelet Responses In Vivo and In Vitro

1992 ◽  
Vol 68 (06) ◽  
pp. 687-693 ◽  
Author(s):  
P T Larsson ◽  
N H Wallén ◽  
A Martinsson ◽  
N Egberg ◽  
P Hjemdahl
Keyword(s):  
Ex Vivo ◽  
High Dose ◽  
Platelet Aggregability ◽  
Adrenoceptor Agonist ◽  
Dose Infusion ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Factor Antigen

SummaryThe significance of platelet β-adrenoceptors for platelet responses to adrenergic stimuli in vivo and in vitro was studied in healthy volunteers. Low dose infusion of the β-adrenoceptor agonist isoprenaline decreased platelet aggregability in vivo as measured by ex vivo filtragometry. Infusion of adrenaline, a mixed α- and β-adrenoceptor agonist, increased platelet aggregability in vivo markedly, as measured by ex vivo filtragometry and plasma β-thromboglobulin levels. Adrenaline levels were 3–4 nM in venous plasma during infusion. Both adrenaline and high dose isoprenaline elevated plasma von Willebrand factor antigen levels β-Blockade by propranolol did not alter our measures of platelet aggregability at rest or during adrenaline infusions, but inhibited adrenaline-induced increases in vWf:ag. In a model using filtragometry to assess platelet aggregability in whole blood in vitro, propranolol enhanced the proaggregatory actions of 5 nM, but not of 10 nM adrenaline. The present data suggest that β-adrenoceptor stimulation can inhibit platelet function in vivo but that effects of adrenaline at high physiological concentrations are dominated by an α-adrenoceptor mediated proaggregatory action.

In Vivo Effect of Suloctidil as an Antiplatelet Agent

1979 ◽  
Vol 41 (03) ◽  
pp. 465-474 ◽  
Author(s):  
Marcia R Stelzer ◽  
Thomas S Burns ◽  
Robert N Saunders
Keyword(s):  
Ex Vivo ◽  
Antiplatelet Agent ◽  
Ratio Method ◽  
Platelet Aggregate ◽  
Permanent Effect ◽  
Platelet Aggregates ◽  
5 Ht Uptake ◽  
High Doses

SummaryThe relationship between the effects of suloctidil in vivo as an antiplatelet agent and in vitro as a modifier of platelet serotonin (5-HT) parameters was investigated. Suloctidil was found to be effective in reducing platelet aggregates formation in the retired breeder rat as determined using the platelet aggregate ratio method (PAR) with an ED50 of 16.1 mg/kg 24 hours post administration. In contrast to the hypothesis that 5-HT depletion is involved in the anti-aggregatory mechanism of suloctidil, no correlation was found between platelet 5- HT content and this antiplatelet activity. Reduction of platelet 5-HT content required multiple injections of high doses (100 mg/kg/day) of suloctidil. Suloctidil administration for 8 days at 100 mg/kg/day, which lowered platelet 5-HT content by 50%, resulted in no permanent effect on ex vivo platelet 5-HT uptake or thrombin-induced release, nor alteration in the plasma 5-HT level. However, these platelets exhibited a short-lived, significant increase in percent leakage of 5-HT after 30 minutes of incubation. Therefore, suloctidil treatment at high doses may with time result in platelet 5-HT depletion, however this effect is probably not related to the primary anti-aggregatory activity of the drug.

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