The antiviral effect of metformin on zika and dengue virus infection

AbstractThe Dengue (DENV) and zika (ZIKV) virus infections are currently a public health concern. At present, there is no treatment or a safe and effective vaccine for these viruses. Hence, the development of new strategies as host-directed therapy is required. In this sense, Metformin (MET), an FDA-approved drug used for the treatment of type 2 diabetes, has shown an anti-DENV effect in vitro by activating AMPK and reducing HMGCR activity. In this study, MET treatment was evaluated during in vitro and in vivo ZIKV infection and compared to MET treatment during DENV infection. Our results demonstrated that MET has a broad in vitro antiviral spectrum. MET inhibited ZIKV infection in different cell lines, but it was most effective in inhibiting DENV and yellow fever virus (YFV) infection in Huh-7 cells. However, the drug failed to protect against ZIKV infection when AG129 immunodeficient mice were used as in vivo model. Interestingly, MET increased DENV-infected male mice's survival time, reducing the severe signs of the disease. Together, these findings indicate that, although MET was an effective antiviral agent to inhibit in vitro and in vivo DENV infection, it could only inhibit in vitro ZIKV infection.

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Macrophages prevent human red blood cell reconstitution in immunodeficient mice

Blood ◽

10.1182/blood-2010-11-321414 ◽

2011 ◽

Vol 118 (22) ◽

pp. 5938-5946 ◽

Cited By ~ 84

Author(s):

Zheng Hu ◽

Nico Van Rooijen ◽

Yong-Guang Yang

Keyword(s):

Fetal Liver ◽

In Vivo Model ◽

Thymic Tissue ◽

Immunodeficient Mice ◽

Human Erythropoietin ◽

Human Cd34 ◽

Biologic Function ◽

Human Rbcs

Abstract An animal model supporting human erythropoiesis will be highly valuable for assessing the biologic function of human RBCs under physiologic and disease settings, and for evaluating protocols of in vitro RBC differentiation. Herein, we analyzed human RBC reconstitution in NOD/SCID or NOD/SCID/γc−/− mice that were transplanted with human CD34+ fetal liver cells and fetal thymic tissue. Although a large number of human CD45−CD71+ nucleated immature erythroid cells were detected in the bone marrow, human RBCs were undetectable in the blood of these mice. Human RBCs became detectable in blood after macrophage depletion but disappeared again after withdrawal of treatment. Furthermore, treatment with human erythropoietin and IL-3 significantly increased human RBC reconstitution in macrophage-depleted, but not control, humanized mice. Significantly more rapid rejection of human RBCs than CD47-deficient mouse RBCs indicates that mechanisms other than insufficient CD47-SIRPα signaling are involved in human RBC xenorejection in mice. All considered, our data demonstrate that human RBCs are highly susceptible to rejection by macrophages in immunodeficient mice. Thus, strategies for preventing human RBC rejection by macrophages are required for using immunodeficient mice as an in vivo model to study human erythropoiesis and RBC function.

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AT-752, a double prodrug of a guanosine nucleotide analog, inhibits yellow fever virus in a hamster model

10.1101/2021.10.25.465665 ◽

2021 ◽

Author(s):

Kai Lin ◽

Steven S Good ◽

Justin G. Julander ◽

Abbie Weight ◽

Adel Moussa

Keyword(s):

Yellow Fever ◽

Yellow Fever Virus ◽

Limit Of Detection ◽

Virus Titer ◽

Fever Virus ◽

Effective Vaccine ◽

Hamster Model ◽

Nucleotide Analog

Yellow fever virus (YFV) is a zoonotic pathogen re-emerging in parts of the world, causing a viral hemorrhagic fever associated with high mortality rates. While an effective vaccine is available, having an effective antiviral against YFV is critical against unexpected outbreaks, or when vaccination is not recommended. We have previously identified AT-281, the free base of AT-752, an orally available double prodrug of a guanosine nucleotide analog, as a potent inhibitor of YFV in vitro , with a 50% effective concentration (EC 50 ) of 0.31 µM. In hamsters infected with YFV (Jimenez strain), viremia rose about 4 log 10 -fold and serum alanine aminotransferase (ALT) 2-fold compared to sham-infected animals. Treatment with 1000 mg/kg AT-752 for 7 days, initiated 4 h prior to viral challenge, reduced viremia to below the limit of detection by day 4 post infection (pi) and returned ALT to normal levels by day 6 pi. When treatment with AT-752 was initiated 2 days pi, the virus titer and ALT dropped >2 log 10 and 53% by day 4 and 6 pi, respectively. In addition, at 21 days pi, 70 – 100% of the infected animals in the treatment groups survived compared to 0% of the untreated group (p<0.001). Moreover, in vivo formation of the active triphosphate metabolite AT-9010 was measured in the animal tissues, with the highest concentrations in liver and kidney, organs that are vulnerable to the virus. The demonstrated in vivo activity of AT-752 suggests that it is a promising compound for clinical development in the treatment of YFV infection.

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Antitumor Effects of Systemic DNAse I and Proteases in an In Vivo Model

Integrative Cancer Therapies ◽

10.1177/1534735416631102 ◽

2016 ◽

Vol 15 (4) ◽

pp. NP35-NP43 ◽

Cited By ~ 10

Author(s):

Catalina Trejo-Becerril ◽

Enrique Pérez-Cardenas ◽

Blanca Gutiérrez-Díaz ◽

Desiree De La Cruz-Sigüenza ◽

Lucía Taja-Chayeb ◽

...

Keyword(s):

Cancer Patients ◽

Antitumor Effect ◽

Dnase I ◽

In Vivo Model ◽

Circulating Dna ◽

Healthy Individuals ◽

Antitumor Effects ◽

Immunodeficient Mice

Background. Cell-free DNA circulates in cancer patients and induces in vivo cell transformation and cancer progression in susceptible cells. Based on this, we hypothesized that depletion of circulating DNA with DNAse I and a protease mix could have antitumor effects. Study design. The study aimed to demonstrate that DNAse I and a protease mix can degrade in vitro DNA and proteins from the serum of healthy individuals and cancer patients, and in vivo in serum of Wistar rats,. Moreover, the antitumor effect of the systemically administered enzyme mix treatmentwas evaluated in nude mice subcutaneously grafted with the human colon cancer cell line SW480. Results. The serum DNA of cancer patients or healthy individuals was almost completely degraded in vitro by the enzymatic treatment, but no degradation was found with the enzymes given separately. The intravenous administration of the enzymes led to significant decreases in DNA and proteins from rat serum. No antitumor effect was observed in immunodeficient mice treated with the enzymes given separately. In contrast, the animals that received both enzymes exhibited a marked growth inhibition of tumors, 40% of them having pathological complete response. Conclusion. This study demonstrated that systemic treatment with DNAse I and a protease mix in rats decreases DNA and proteins from serum and that this treatment has antitumor effects. Our results support the hypothesis that circulating DNA could have a role in tumor progression, which can be offset by depleting it. Further studies are needed to prove this concept.

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Immature human cord blood progenitors engraft and proliferate to high levels in severe combined immunodeficient mice

Blood ◽

10.1182/blood.v83.9.2489.2489 ◽

1994 ◽

Vol 83 (9) ◽

pp. 2489-2497 ◽

Cited By ~ 14

Author(s):

J Vormoor ◽

T Lapidot ◽

F Pflumio ◽

G Risdon ◽

B Patterson ◽

...

Keyword(s):

Cord Blood ◽

Dna Analysis ◽

Hematopoietic Cells ◽

In Vivo Model ◽

Erythroid Progenitors ◽

Human Cord Blood ◽

Immunodeficient Mice ◽

High Level

Abstract Unseparated or Ficoll-Hypaque (Pharmacia, Piscataway, NJ)--fractionated human cord blood cells were transplanted into sublethally irradiated severe combined immunodeficient (SCID) mice. High levels of multilineage engraftment, including myeloid and lymphoid lineages, were obtained with 80% of the donor samples as assessed by DNA analysis, fluorescence-activated cell sorting (FACS), and morphology. In contrast to previous and concurrent studies with adult human bone marrow (BM), treatment with human cytokines was not required to establish high-level human cell engraftment, suggesting that neonatal cells either respond differently to the murine microenvironment or they provide their own cytokines in a paracrine fashion. Committed and multipotential myelo- erythroid progenitors were detected using in vitro colony assays and FACS analysis of the murine BM showed the presence of immature CD34+ cells. In addition, human hematopoiesis was maintained for at least 14 weeks providing further evidence that immature hematopoietic precursors had engrafted the murine BM. This in vivo model for human cord blood- derived hematopoiesis will be useful to gain new insights into the biology of neonatal hematopoietic cells and to evaluate their role in gene therapy. There is growing evidence that there are ontogeny-related changes in immature human hematopoietic cells, and therefore, the animal models we have developed for adult and neonatal human hematopoiesis provide useful tools to evaluate these changes in vivo.

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Cocculus hirsutus-derived phytopharmaceutical drug has potent anti-dengue activity

10.1101/2020.09.18.303149 ◽

2020 ◽

Author(s):

Ankur Poddar ◽

Rahul Shukla ◽

Hemalatha Beesetti ◽

Upasana Arora ◽

Ravi Kant Rajpoot ◽

...

Keyword(s):

At Risk ◽

Aqueous Extract ◽

Aerial Part ◽

Lethal Dose ◽

Drug Substance ◽

Health Concern ◽

Effective Vaccine ◽

Cocculus Hirsutus

AbstractBackgroundDengue is a serious public health concern worldwide, with ~3 billion people at risk of contracting dengue virus (DENV) infections. Currently, no effective vaccine or drug is available for the prevention or treatment of dengue, which leaves only anti-mosquito strategies to combat this disease. The present study was initiated to determine the in-vitro and in vivo protective effects of a plant-derived phytopharmaceutical drug for the treatment of dengue.Methodology/Principal FindingsIn our previous report, we had identified methanolic extract of the aerial parts of Cissampelos pareira to exhibit in vitro and in vivo anti-dengue activity against all the four DENV serotypes. In the current study, we have identified another Indian medicinal plant, Cocculus hirsutus, which has a more potent anti-dengue activity than C. pareira. The activity has been evaluated through flow-cytometry-based virus inhibition assay. Interestingly, the stem of C. hirsutus was found to be more potent than the aerial part irrespective of the extraction solvent used viz., denatured spirit, hydro-alcohol (50:50) and water. Hence, the aqueous extract of stem of C. hirsutus (AQCH) was further advanced for investigations because of greater regulatory acceptance. The AQCH exhibited dose-dependent inhibition of release of DENV and its secretory antigen, NS1. Five chemical markers viz. Sinococuline, 20-Hydroxyecdysone, Makisterone-A, Magnoflorine and Coniferyl alcohol were identified as the major chemical ingredients of the AQCH extract. These chemicals were subsequently used for extract standardisation. Importantly, AQCH completely protected AG129 mice at 25 mg/kg/dose body weight when fed 4 times a day post-infection with a lethal dose of DENV-2 S221 strain. Because of its potential as an effective phytopharmaceutical drug against dengue, AQCH, has been formulated into tablets for further pre-clinical and clinical developments.Conclusions/SignificanceWe provide evidence of the pan anti-dengue potential of C. hirsutus-based phytopharmaceutical drug as determined through in vitro and in vivo experiments. We have also characterized five chemical entities in the drug substance, which provides means for standardization of drug substance and drug product. Based on these findings, a program to develop a safe and effective C. hirsutus-derived phytopharmaceutical drug for the treatment of dengue has been initiated.Author summaryThere is an urgent need to develop a safe and effective drug against dengue, which is a rapidly expanding mosquito-borne viral disease. Half of the world’s population has been estimated to be at risk of contracting this disease and the situation remains grim due to lack of an approved drug. We aimed to develop an ethnopharmacological drug against dengue by exploring traditional Indian medicinal science, Ayurveda. This led us to identify a creeper, Cocculus hirsutus, as a more potent anti-dengue plant than Cissampelos pareira, reported in our earlier published study. The stem part of C. hirsutus was found to be more efficacious in inhibiting the propagation of dengue viruses (DENVs) in cell culture than its aerial part. Hence, we chose to advance aqueous extract of stem of C. hirsutus (AQCH) for further studies. Importantly, AQCH also protected immune-compromised mice from lethal DENV infection, which is suggestive of its potential clinical relevance. We have identified five chemical marker compounds in AQCH to gauge the quality and consistency of extract preparation and its formulation into stable tablets. Based on the findings of this study, we have undertaken the development of a safe and effective C. hirsutus-derived phytopharmaceutical drug for the treatment of dengue.

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Immature human cord blood progenitors engraft and proliferate to high levels in severe combined immunodeficient mice

Blood ◽

10.1182/blood.v83.9.2489.bloodjournal8392489 ◽

1994 ◽

Vol 83 (9) ◽

pp. 2489-2497 ◽

Cited By ~ 199

Author(s):

J Vormoor ◽

T Lapidot ◽

F Pflumio ◽

G Risdon ◽

B Patterson ◽

...

Keyword(s):

Cord Blood ◽

Dna Analysis ◽

Hematopoietic Cells ◽

In Vivo Model ◽

Erythroid Progenitors ◽

Human Cord Blood ◽

Immunodeficient Mice ◽

High Level

Unseparated or Ficoll-Hypaque (Pharmacia, Piscataway, NJ)--fractionated human cord blood cells were transplanted into sublethally irradiated severe combined immunodeficient (SCID) mice. High levels of multilineage engraftment, including myeloid and lymphoid lineages, were obtained with 80% of the donor samples as assessed by DNA analysis, fluorescence-activated cell sorting (FACS), and morphology. In contrast to previous and concurrent studies with adult human bone marrow (BM), treatment with human cytokines was not required to establish high-level human cell engraftment, suggesting that neonatal cells either respond differently to the murine microenvironment or they provide their own cytokines in a paracrine fashion. Committed and multipotential myelo- erythroid progenitors were detected using in vitro colony assays and FACS analysis of the murine BM showed the presence of immature CD34+ cells. In addition, human hematopoiesis was maintained for at least 14 weeks providing further evidence that immature hematopoietic precursors had engrafted the murine BM. This in vivo model for human cord blood- derived hematopoiesis will be useful to gain new insights into the biology of neonatal hematopoietic cells and to evaluate their role in gene therapy. There is growing evidence that there are ontogeny-related changes in immature human hematopoietic cells, and therefore, the animal models we have developed for adult and neonatal human hematopoiesis provide useful tools to evaluate these changes in vivo.

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A single dose of recombinant VSV-∆G-spike vaccine provides protection against SARS-CoV-2 challenge

Nature Communications ◽

10.1038/s41467-020-20228-7 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Yfat Yahalom-Ronen ◽

Hadas Tamir ◽

Sharon Melamed ◽

Boaz Politi ◽

Ohad Shifman ◽

...

Keyword(s):

Single Dose ◽

Neutralizing Antibodies ◽

Rapid Development ◽

Body Weight Loss ◽

Spike Protein ◽

Effective Vaccine ◽

In Vivo Model ◽

Golden Syrian Hamster

AbstractThe COVID-19 pandemic caused by SARS-CoV-2 imposes an urgent need for rapid development of an efficient and cost-effective vaccine, suitable for mass immunization. Here, we show the development of a replication competent recombinant VSV-∆G-spike vaccine, in which the glycoprotein of VSV is replaced by the spike protein of SARS-CoV-2. In-vitro characterization of this vaccine indicates the expression and presentation of the spike protein on the viral membrane with antigenic similarity to SARS-CoV-2. A golden Syrian hamster in-vivo model for COVID-19 is implemented. We show that a single-dose vaccination results in a rapid and potent induction of SARS-CoV-2 neutralizing antibodies. Importantly, vaccination protects hamsters against SARS-CoV-2 challenge, as demonstrated by the abrogation of body weight loss, and alleviation of the extensive tissue damage and viral loads in lungs and nasal turbinates. Taken together, we suggest the recombinant VSV-∆G-spike as a safe, efficacious and protective vaccine against SARS-CoV-2.

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Zika Virus-Specific IgY Results Are Therapeutic Following a Lethal Zika Virus Challenge without Inducing Antibody-Dependent Enhancement

Viruses ◽

10.3390/v11030301 ◽

2019 ◽

Vol 11 (3) ◽

pp. 301 ◽

Cited By ~ 2

Author(s):

Kyle O’Donnell ◽

Bernadette Meberg ◽

James Schiltz ◽

Matthew Nilles ◽

David Bradley

Keyword(s):

Zika Virus ◽

Denv Infection ◽

Western Hemisphere ◽

World Health ◽

Zikv Infection ◽

Antibody Dependent Enhancement ◽

Virus Challenge ◽

Health Organization

The Zika virus (ZIKV) is a newly emerged pathogen in the Western hemisphere. It was declared a global health emergency by the World Health Organization in 2016. There have been 223,477 confirmed cases, including 3720 congenital syndrome cases since 2015. ZIKV infection symptoms range from asymptomatic to Gullain–Barré syndrome and extensive neuropathology in infected fetuses. Passive and active vaccines have been unsuccessful in the protection from or the treatment of flaviviral infections due to antibody-dependent enhancement (ADE). ADE causes an increased viral load due to an increased monocyte opsonization by non-neutralizing, low-avidity antibodies from a previous dengue virus (DENV) infection or from a previous exposure to ZIKV. We have previously demonstrated that polyclonal avian IgY generated against whole-killed DENV-2 ameliorates DENV infection in mice while not inducing ADE. This is likely due to the inability of the Fc portion of IgY to bind to mammalian Fc receptors. We have shown here that ZIKV oligoclonal IgY is able to neutralize the virus in vitro and in IFNAR−/− mice. The concentration of ZIKV-specific IgY yielding 50% neutralization (NT50) was 25 µg/mL. The exposure of the ZIKV, prior to culture with ZIKV-specific IgY or 4G2 flavivirus-enveloped IgG, demonstrated that the ZIKV-specific IgY does not induce ADE. ZIKV IgY was protective in vivo when administered following a lethal ZIKV challenge in 3-week-old IFNAR−/− mice. We propose polyclonal ZIKV-specific IgY may provide a viable passive immunotherapy for a ZIKV infection without inducing ADE.

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The Bioactive Lipid 4-Hydroxyphenyl Retinamide Inhibits Flavivirus Replication

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04177-14 ◽

2014 ◽

Vol 59 (1) ◽

pp. 85-95 ◽

Cited By ~ 30

Author(s):

Margot Carocci ◽

Stephen M. Hinshaw ◽

Mary A. Rodgers ◽

Valerie A. Villareal ◽

Dominique J. Burri ◽

...

Keyword(s):

Cell Culture ◽

Antiviral Activity ◽

Mammalian Cell Culture ◽

Antiviral Agent ◽

Denv Infection ◽

Effective Vaccine ◽

Bioactive Lipids ◽

Content Type ◽

Long Chain

ABSTRACTDengue virus (DENV), a member of theFlaviviridaefamily, is a mosquito-borne pathogen and the cause of dengue fever. The increasing prevalence of DENV worldwide heightens the need for an effective vaccine and specific antivirals. Due to the dependence of DENV upon the lipid biosynthetic machinery of the host cell, lipid signaling and metabolism present unique opportunities for inhibiting viral replication. We screened a library of bioactive lipids and modulators of lipid metabolism and identified 4-hydroxyphenyl retinamide (4-HPR) (fenretinide) as an inhibitor of DENV in cell culture. 4-HPR inhibits the steady-state accumulation of viral genomic RNA and reduces viremia when orally administered in a murine model of DENV infection. The molecular target responsible for this antiviral activity is distinct from other known inhibitors of DENV but appears to affect other members of theFlaviviridae, including the West Nile, Modoc, and hepatitis C viruses. Although long-chain ceramides have been implicated in DENV replication, we demonstrate that DENV is insensitive to the perturbation of long-chain ceramides in mammalian cell culture and that the effect of 4-HPR on dihydroceramide homeostasis is separable from its antiviral activity. Likewise, the induction of reactive oxygen species by 4-HPR is not required for the inhibition of DENV. The inhibition of DENVin vivoby 4-HPR, combined with its well-established safety and tolerability in humans, suggests that it may be repurposed as a pan-Flaviviridaeantiviral agent. This work also illustrates the utility of bioactive lipid screens for identifying critical interactions of DENV and other viral pathogens with host lipid biosynthesis, metabolism, and signal transduction.

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Yellow fever virus is susceptible to sofosbuvir both in vitro and in vivo

10.1101/266361 ◽

2018 ◽

Cited By ~ 3

Author(s):

Caroline S. de Freitas ◽

Luiza M. Higa ◽

Carolina Sacramento ◽

André C. Ferreira ◽

Patrícia A. Reis ◽

...

Keyword(s):

Yellow Fever ◽

Yellow Fever Virus ◽

Clinical Results ◽

Fever Virus ◽

Health Concern ◽

Public Health Concern ◽

Human Hepatoma Cells ◽

Attractive Option

AbstractYellow fever virus (YFV) is a member of the Flaviviridae family, that causes major mortality. In Brazil, YFV activity increased in the last years. It has been registered that sylvatic, instead of urban, yellow fever (YF) leads our contemporary public health concern. Low vaccinal coverage leaves the human population near the jangle vulnerable to the outbreak, making it necessary to identify therapeutic options. Repurposing of clinically approved antiviral drugs represents an alternative for such identification. Other Flaviviruses, such Zika (ZIKV) and dengue (DENV) viruses, are susceptible to Sofosbuvir, a clinically approved drug against hepatitis C virus (HCV). Moreover, sofosbuvir has a safety record on critically ill hepatic patients, making it an attractive option. Our data show that YFV RNA polymerase uses conserved amino acid resides for nucleotide binding to dock sofosbuvir. This drug inhibited YFV replication in different lineages of human hepatoma cells, Huh-7 and HepG2, with EC50 value of 4.8 µM. Sofosbuvir protected YFV-infected neonatal Swiss mice from mortality and weight loss. Our pre-clinical results indicate that sofosbuvir could represent an option against YFV.

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