scholarly journals Influence of FcγRIIa-Expressing Cells on the Assessment of Neutralizing and Enhancing Serum Antibodies Elicited by a Live-Attenuated Tetravalent Dengue Vaccine

2015 ◽  
Vol 2 (4) ◽  
Author(s):  
Anthony M. Byers ◽  
Ryan Broder ◽  
Kelly Haupfear ◽  
Tatyana M. Timiryasova ◽  
Branda T. Hu ◽  
...  
Keyword(s):  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Vero Cells ◽  
Denv Infection ◽  
Dengue Vaccine ◽  
Fcγ Receptors ◽  
Dengue Disease ◽  
Point Estimates ◽  
High Dilutions

Abstract Background.  Recent trials of recombinant, live-attenuated chimeric yellow fever-dengue tetravalent dengue vaccine (CYD-TDV) demonstrated efficacy against symptomatic, virologically confirmed dengue disease with higher point estimates of efficacy toward dengue virus (DENV)3 and DENV4 and moderate levels toward DENV1 and DENV2. It is interesting to note that serotype-specific efficacy did not correlate with absolute neutralizing antibody (nAb) geometric mean titer (GMT) values measured in a Vero-based plaque reduction neutralization test assay. The absence of Fcγ receptors on Vero cells may explain this observation. Methods.  We performed parallel seroneutralization assays in Vero cells and CV-1 cells that express FcγRIIa (CV-1-Fc) to determine the neutralizing and enhancing capacity of serotype-specific DENV Abs present in CYD-TDV clinical trial sera. Results.  Enhancement of DENV infection was observed in CV-1-Fc cells in naturally exposed nonvaccine sera, mostly for DENV3 and DENV4, at high dilutions. The CYD-TDV-vaccinated sera showed similar enhancement patterns. The CV-1-Fc nAb GMT values were 2- to 9-fold lower than Vero for all serotypes in both naturally infected individuals and CYD-TDV-vaccinated subjects with and without previous dengue immunity. The relative (CV-1-Fc/Vero) GMT decrease for anti-DENV1 and anti-DENV2 responses was not greater than for the other serotypes. Conclusions.  In vitro neutralization assays utilizing FcγRIIa-expressing cells provide evidence that serotype-specific Ab enhancement may not be a primary factor in the serotype-specific efficacy differences exhibited in the CYD-TDV trials.

scholarly journals Enhanced dengue vaccine virus replication and neutralizing antibody responses in immune primed rhesus macaques

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Michael K. McCracken ◽  
Caitlin H. Kuklis ◽  
Chandrika B. Kannadka ◽  
David A. Barvir ◽  
Mark A. Sanborn ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Rhesus Macaques ◽  
Neutralizing Antibody ◽  
Denv Infection ◽  
Vaccine Virus ◽  
Dengue Vaccine ◽  
Live Attenuated Vaccine ◽  
Vaccination Strategies ◽  
Inactivated Vaccines

AbstractAntibody-dependent enhancement (ADE) is suspected to influence dengue virus (DENV) infection, but the role ADE plays in vaccination strategies incorporating live attenuated virus components is less clear. Using a heterologous prime-boost strategy in rhesus macaques, we examine the effect of priming with DENV purified inactivated vaccines (PIVs) on a tetravalent live attenuated vaccine (LAV). Sera exhibited low-level neutralizing antibodies (NAb) post PIV priming, yet moderate to high in vitro ADE activity. Following LAV administration, the PIV primed groups exhibited DENV-2 LAV peak viremias up to 1,176-fold higher than the mock primed group, and peak viremia correlated with in vitro ADE. Furthermore, PIV primed groups had more balanced and higher DENV-1–4 NAb seroconversion and titers than the mock primed group following LAV administration. These results have implications for the development of effective DENV vaccine prime-boost strategies and for our understanding of the role played by ADE in modulating DENV replication.

scholarly journals Epitope Determinants of a Chimpanzee Dengue Virus Type 4 (DENV-4)-Neutralizing Antibody and Protection against DENV-4 Challenge in Mice and Rhesus Monkeys by Passively Transferred Humanized Antibody

2007 ◽  
Vol 81 (23) ◽  
pp. 12766-12774 ◽  
Author(s):  
Ching-Juh Lai ◽  
Ana P. Goncalvez ◽  
Ruhe Men ◽  
Claire Wernly ◽  
Olivia Donau ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Virus Type ◽  
High Titer ◽  
Neutralizing Antibody ◽  
Denv Infection ◽  
Passive Transfer ◽  
Escape Mutant ◽  
Protective Capacity

ABSTRACT The chimpanzee monoclonal antibody (MAb) 5H2 is specific for dengue virus type 4 (DENV-4) and neutralizes the virus at a high titer in vitro. The epitope detected by the antibody was mapped by sequencing neutralization escape variants of the virus. One variant contained a Lys174-Glu substitution and another contained a Pro176-Leu substitution in domain I of the DENV-4 envelope protein (E). These mutations reduced binding affinity for the antibody 18- to >100-fold. Humanized immunoglobulin G (IgG) 5H2, originally produced from an expression vector, has been shown to be a variant containing a nine-amino-acid deletion in the Fc region which completely ablates antibody-dependent enhancement of DENV replication in vitro. The variant MAb, termed IgG 5H2 ΔD, is particularly attractive for exploring its protective capacity in vivo. Passive transfer of IgG 5H2 ΔD at 20 μg/mouse afforded 50% protection of suckling mice against challenge with 25 50% lethal doses of mouse neurovirulent DENV-4 strain H241. Passive transfer of antibody to monkeys was conducted to demonstrate proof of concept for protection against DENV challenge. Monkeys that received 2 mg/kg of body weight of IgG 5H2 ΔD were completely protected against 100 50% monkey infectious doses (MID50) of DENV-4, as indicated by the absence of viremia and seroconversion. A DENV-4 escape mutant that contained a Lys174-Glu substitution identical to that found in vitro was isolated from monkeys challenged with 106 MID50 of DENV-4. This substitution was also present in all naturally occurring isolates belonging to DENV-4 genotype III. These studies have important implications for possible antibody-mediated prevention of DENV infection.

A drug-drug interaction (DDI) study to assess the effect of oral galeterone on the pharmacokinetics (PK) of oral midazolam.

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 316-316
Author(s):  
Karen J. Ferrante ◽  
Douglas B Jacoby ◽  
Daryl Sonnichsen
Keyword(s):  
Geometric Mean ◽  
Point Estimate ◽  
Open Label ◽  
Fixed Sequence ◽  
Geometric Means ◽  
Fda Guidance ◽  
Point Estimates ◽  
Oral Midazolam ◽  
Androgen Binding

316 Background: Galeterone (gal) is a semisynthetic steroid that targets androgen receptor (AR) signaling via increased AR protein degradation, inhibition of CYP17 activity, and inhibition of androgen binding to AR. Gal is a novel potential treatment for prostate cancer. In vitro, gal competitively inhibits CYP3A4 (IC50 = 5.5 μM; midazolam as substrate). This clinical study evaluated whether multiple daily doses of gal alter the single-dose PK of midazolam, a sensitive probe substrate for functional CYP3A4 intestinal and hepatic activity. Methods: In an open-label, fixed sequence, DDI study, 18 healthy male volunteers received midazolam 2 mg Day 1 and Day 5 and gal 2550 mg Days 2-5. Midazolam plasma PK was determined on Days 1 and 5. The effect of gal on the natural log-transformed Cmax, AUC0-inf, and AUC0-t of midazolam was assessed with a linear mixed-effects model; point estimates for geometric means, geometric mean ratios with 90% confidence intervals were determined. Safety was also monitored. Results: The Tmax of midazolam was not altered by gal coadministration. The < 2-fold increases in midazolam Cmax and AUCs were statistically significant. For Cmax, the point estimate of the geometric least squares (LS) mean ratio between the 2 treatments was 1.25 (90% CI: 1.05, 1.48). Higher ratios were observed for the AUC ratios, with LS mean ratio for AUC0-t of 1.57 (90% CI: 1.43, 1.73) and for AUC0-inf of 1.58 (90% CI: 1.42, 1.75). The mean midazolam t1/2 was approximately 76% higher with gal coadministration. Multiple doses of gal were well tolerated with no apparent effect on the safety of midazolam. Conclusions: Per FDA guidance, < 2-fold increases in midazolam Cmax and AUCs observed with gal coadministration support its classification as a weak inhibitor of CYP3A4. Given the similar or higher in vitro IC50’s for CYP2C8 and CYP2C19, respectively, a comparable or lesser degree of enzyme inhibition is expected for gal 2550 mg daily. Based on these results, concurrent CYP3A4, CYP2C8, and CYP2C19 substrates are not contraindicated in patients taking gal; caution is advised in patients receiving or initiating sensitive CYP3A4, CYP2C8, and CYP2C19 substrates, especially those with a narrow therapeutic range.

scholarly journals Novel Benzoxazole Inhibitor of Dengue Virus Replication That Targets the NS3 Helicase

2013 ◽  
Vol 57 (4) ◽  
pp. 1902-1912 ◽  
Author(s):  
Chelsea M. Byrd ◽  
Douglas W. Grosenbach ◽  
Aklile Berhanu ◽  
Dongcheng Dai ◽  
Kevin F. Jones ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Molecular Beacon ◽  
Single Point ◽  
Denv Infection ◽  
Geographic Region ◽  
Single Point Mutation ◽  
Helicase Domain ◽  
Viral Pathogen ◽  
Dengue Disease

ABSTRACTDengue virus (DENV) is the predominant mosquito-borne viral pathogen that infects humans with an estimated 50 to 100 million infections per year worldwide. Over the past 50 years, the incidence of dengue disease has increased dramatically and the virus is now endemic in more than 100 countries. Moreover, multiple serotypes of DENV are now found in the same geographic region, increasing the likelihood of more severe forms of disease. Despite extensive research, there are still no approved vaccines or therapeutics commercially available to treat DENV infection. Here we report the results of a high-throughput screen of a chemical compound library using a whole-virus assay that identified a novel small-molecule inhibitor of DENV, ST-610, that potently and selectively inhibits all four serotypes of DENV replicationin vitro. Sequence analysis of drug-resistant virus isolates has identified a single point mutation, A263T, in the NS3 helicase domain that confers resistance to this compound. ST-610 inhibits DENV NS3 helicase RNA unwinding activity in a molecular-beacon-based helicase assay but does not inhibit nucleoside triphosphatase activity based on a malachite green ATPase assay. ST-610 is nonmutagenic, is well tolerated (nontoxic) in mice, and has shown efficacy in a sublethal murine model of DENV infection with the ability to significantly reduce viremia and viral load compared to vehicle controls.

scholarly journals An Immunogenic and Protective Alphavirus Replicon Particle-Based Dengue Vaccine Overcomes Maternal Antibody Interference in Weanling Mice

2007 ◽  
Vol 81 (19) ◽  
pp. 10329-10339 ◽  
Author(s):  
Laura J. White ◽  
Melissa M. Parsons ◽  
Alan C. Whitmore ◽  
Brandon M. Williams ◽  
Aravinda de Silva ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Protective Efficacy ◽  
Neutralizing Antibody ◽  
Gene Cassette ◽  
Vero Cells ◽  
Envelope Proteins ◽  
Maternal Antibodies ◽  
Booster Immunization ◽  
Replicon Particle

ABSTRACT A candidate pediatric dengue virus (DENV) vaccine based on nonpropagating Venezuelan equine encephalitis virus replicon particles (VRP) was tested for immunogenicity and protective efficacy in weanling mice in the presence and absence of potentially interfering maternal antibodies. A gene cassette encoding envelope proteins prM and E from mouse-adapted DENV type 2 (DENV2) strain NGC was cloned into a VEE replicon vector and packaged into VRP, which programmed proper in vitro expression and processing of DENV2 envelope proteins upon infection of Vero cells. Primary immunization of 3-week-old weanling BALB/c mice in the footpad with DENV2 VRP resulted in high levels of DENV-specific serum immunoglobulin G antibodies and significant titers of neutralizing antibodies in all vaccinates. A booster immunization 12 weeks after the prime immunization resulted in increased neutralizing antibodies that were sustained for at least 30 weeks. Immunization at a range of doses of DENV2 VRP protected mice from an otherwise-lethal intracranial DENV2 challenge. To model vaccination in the presence of maternal antibodies, weanling pups born to DENV2-immune or DENV2-naïve dams were immunized with either DENV2 VRP or live DENV2 given peripherally. The DENV2 VRP vaccine induced neutralizing-antibody responses in young mice regardless of the maternal immune status. In contrast, live-DENV2 vaccination performed poorly in the presence of preexisting anti-DENV2 antibodies. This study demonstrates the feasibility of a VRP vaccine approach as an early-life DENV vaccine in populations with high levels of circulating DENV antibodies and suggests the utility of VRP-based vaccines in other instances where maternal antibodies make early vaccination problematic.

scholarly journals Targeting the Annexin A1-FPR2/ALX pathway for host-directed therapy in dengue disease

2021 ◽  
Author(s):  
Vivian Vasconcelos Costa ◽  
Michelle A Sugimoto ◽  
Josy Hubner ◽  
Caio S Bonilha ◽  
Celso Martins Queiroz-Junior ◽  
...  
Keyword(s):  
Immune Responses ◽  
Denv Infection ◽  
Annexin A1 ◽  
Cytokine Storm ◽  
Dengue Disease ◽  
Host Immune Responses ◽  
Inflammation Resolution ◽  
Circulating Levels

Host immune responses contribute to dengue's pathogenesis and severity, yet the possibility that failure in endogenous inflammation resolution pathways could characterise the disease has not been contemplated. The pro-resolving protein Annexin A1 (AnxA1) is known to counterbalance overexuberant inflammation and mast cell (MC) activation. We hypothesised that inadequate AnxA1 engagement underlies the cytokine storm and vascular pathologies associated with dengue disease. Levels of AnxA1 were examined in the plasma of dengue patients and infected mice. Immunocompetent, IFNα/βR-/-, AnxA1-/- and FPR2/ALX-/- mice were infected with Dengue virus (DENV) and treated with the AnxA1 mimetic peptide Ac2-26 for analysis. Additionally, the effect of Ac2-26 on DENV-induced MC degranulation was assessed in vitro and in vivo. We observed that circulating levels of AnxA1 were reduced in dengue patients and DENV-infected mice. While the absence of AnxA1 or its receptor FPR2/ALX aggravated illness in infected mice, treatment with AnxA1 agonistic peptide attenuated disease manifestations. Both clinical outcomes were attributed to modulation of DENV-mediated viral load-independent MC degranulation. We have thereby identified that altered levels of the pro-resolving mediator AnxA1 are of pathological relevance in DENV infection, suggesting FPR2/ALX agonists as a therapeutic target for dengue disease.

scholarly journals Antiviral activities of curcumin and 6‐gingerol against infection of four dengue virus serotypes in A549 human cell line in vitro

2021 ◽  
Vol 26 (1) ◽  
pp. 41
Author(s):  
Jonathan Alvin Nugraha Halim ◽  
Stefanie Natalia Halim ◽  
Dionisius Denis ◽  
Sotianingsih Haryanto ◽  
Edi Dharmana ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Cell Line ◽  
Curcuma Longa ◽  
Treatment Strategies ◽  
A549 Cells ◽  
Denv Infection ◽  
Active Constituent ◽  
Dengue Disease ◽  
Denv Serotypes

Dengue virus (DENV) is the most geographically widespread arbovirus causing dengue disease epidemics in tropical and subtropical regions. Nature provides abundant plants as a source for lead molecules against various diseases including DENV infection. We investigated the antiviral effect of curcumin and 6‐gingerol, the major active constituent of turmeric (Curcuma longa Linn.) and ginger (Zingiber officinale Roscoe), respectively, against all four serotypes of DENV infecting human lung epithelial carcinoma (A549) cell line in vitro. Both compounds generated cell cytotoxicity to A549 cells at CC50 values of 108 µM for curcumin and 210 µM for 6‐gingerol. The compound curcumin showed antiviral properties as described by IC50 of 20.60, 13.95, 25.54, and 12.35 µM, while 6‐gingerol of 14.70, 14.17, 78.76, and 112.84 µM for DENV‐1, ‐2, ‐3, and ‐4, respectively. Different levels of antiviral properties were observed between DENV serotypes. Our findings suggest that the antiviral assay of compounds against DENV should be performed to all four serotypes and not limited to a particular serotype. In conclusion, curcumin and 6‐gingerol exhibit antiviral properties against DENV infection and could provide a new therapeutic approach for dengue disease treatment strategies.

scholarly journals 2586. Human Breast Milk Inhibits the Replication of Parechovirus-A3

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S899-S899
Author(s):  
Ryohei Izumita ◽  
Kazuki Kon ◽  
Yuta Aizawa ◽  
Kanako Watanabe ◽  
Akihiko Saitoh
Keyword(s):  
Breast Milk ◽  
Neutralizing Antibody ◽  
Antiviral Effect ◽  
Vero Cells ◽  
Human Breast Milk ◽  
Strong Positive Correlation ◽  
Human Breast ◽  
Mature Milk ◽  
Young Infants

Abstract Background Parechovirus-A3 (PeV-A3) is an emerging pathogen causing sepsis and meningoencephalitis in neonates and young infants. We previously reported that maternal antibodies against PeV-A3 are important to protect neonates and young infants from the infection. Recent studies showed that (1) breastfeeding had a protective effect against enterovirus, which is closely-related virus to PeV-A, and (2) human breast milk (HBM) neutralized enterovirus in vitro. Currently, no report is available related to the antiviral effect of HBM against PeV-A3. Methods HBM (colostrum, 3–5 days after childbirth; mature milk, 1 month after childbirth) and serum (within ± 1 week of child’s birthday) samples were obtained from mothers at obstetrics clinic in Niigata, Japan. Neutralizing antibody titers (NATs) against PeV-A3 were measured using the Vero cells. Results The anti-PeV-A3 NATs of colostrum (n = 32) ranged from 1:8 to 1:2048, those ≥1:32 was 59% (19/32). Whereas, the anti-PeV-A3 NATs of mature milk ranged from 1:8 to 1:96. and those ≥1:32 was 20% (2/20) (P < 0.001). The median NATs anti-PeV-A3 was higher in colostrum (1:32) compared with mature milk (1:8) (P < 0.001). There was a strong positive correlation between the NATs of colostrum and serum (r = 0.604, P < 0.001, Figure). Conclusion This study showed that HBM had high NATs against PeV-A3, which was correlated with serum NATs. Further studies are necessary to investigate which components of HBM has antiviral effects against PeV-A3. Disclosures All authors: No reported disclosures.

scholarly journals Delivery of antiviral small interfering RNA with gold nanoparticles inhibits dengue virus infection in vitro

2014 ◽  
Vol 95 (8) ◽  
pp. 1712-1722 ◽  
Author(s):  
Amber M. Paul ◽  
Yongliang Shi ◽  
Dhiraj Acharya ◽  
Jessica R. Douglas ◽  
Amanda Cooley ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Dengue Virus ◽  
Sirna Delivery ◽  
Vero Cells ◽  
Denv Infection ◽  
Small Interfering Rnas ◽  
Virion Release ◽  
Life Threatening

Dengue virus (DENV) infection in humans can cause flu-like illness, life-threatening haemorrhagic fever or even death. There is no specific anti-DENV therapeutic or approved vaccine currently available, partially due to the possibility of antibody-dependent enhancement reaction. Small interfering RNAs (siRNAs) that target specific viral genes are considered a promising therapeutic alternative against DENV infection. However, in vivo, siRNAs are vulnerable to degradation by serum nucleases and rapid renal excretion due to their small size and anionic character. To enhance siRNA delivery and stability, we complexed anti-DENV siRNAs with biocompatible gold nanoparticles (AuNPs) and tested them in vitro. We found that cationic AuNP–siRNA complexes could enter Vero cells and significantly reduce DENV serotype 2 (DENV-2) replication and infectious virion release under both pre- and post-infection conditions. In addition, RNase-treated AuNP–siRNA complexes could still inhibit DENV-2 replication, suggesting that AuNPs maintained siRNA stability. Collectively, these results demonstrated that AuNPs were able to efficiently deliver siRNAs and control infection in vitro, indicating a novel anti-DENV strategy.

scholarly journals Dengue 2 PDK-53 Virus as a Chimeric Carrier for Tetravalent Dengue Vaccine Development

2003 ◽  
Vol 77 (21) ◽  
pp. 11436-11447 ◽  
Author(s):  
Claire Y.-H. Huang ◽  
Siritorn Butrapet ◽  
Kiyotaka R. Tsuchiya ◽  
Natth Bhamarapravati ◽  
Duane J. Gubler ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Neutralizing Antibody ◽  
Vero Cells ◽  
Vaccine Virus ◽  
Wild Type ◽  
Dengue Vaccine ◽  
Virus Challenge ◽  
Viral Interference ◽  
Antibody Titers ◽  
Virus Expression

ABSTRACT Attenuation markers of the candidate dengue 2 (D2) PDK-53 vaccine virus are encoded by mutations that reside outside of the structural gene region of the genome. We engineered nine dengue virus chimeras containing the premembrane (prM) and envelope (E) genes of wild-type D1 16007, D3 16562, or D4 1036 virus within the genetic backgrounds of wild-type D2 16681 virus and the two genetic variants (PDK53-E and PDK53-V) of the D2 PDK-53 vaccine virus. Expression of the heterologous prM-E genes in the genetic backgrounds of the two D2 PDK-53 variants, but not that of wild-type D2 16681 virus, resulted in chimeric viruses that retained PDK-53 characteristic phenotypic markers of attenuation, including small plaque size and temperature sensitivity in LLC-MK2 cells, limited replication in C6/36 cells, and lack of neurovirulence in newborn ICR mice. Chimeric D2/1, D2/3, and D2/4 viruses replicated efficiently in Vero cells and were immunogenic in AG129 mice. Chimeric D2/1 viruses protected adult AG129 mice against lethal D1 virus challenge. Two tetravalent virus formulations, comprised of either PDK53-E- or PDK53-V-vectored viruses, elicited neutralizing antibody titers in mice against all four dengue serotypes. These antibody titers were similar to the titers elicited by monovalent immunizations, suggesting that viral interference did not occur in recipients of the tetravalent formulations. The results of this study demonstrate that the unique attenuation loci of D2 PDK-53 virus make it an attractive vector for the development of live attenuated flavivirus vaccines.

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