scholarly journals In Vitro Neutralization Is Not Predictive of Prophylactic Efficacy of Broadly Neutralizing Monoclonal Antibodies CR6261 and CR9114 against Lethal H2 Influenza Virus Challenge in Mice

2017 ◽  
Vol 91 (24) ◽  
Author(s):  
Troy C. Sutton ◽  
Elaine W. Lamirande ◽  
Kevin W. Bock ◽  
Ian N. Moore ◽  
Wouter Koudstaal ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Severe Disease ◽  
Influenza Viruses ◽  
Animal Origin ◽  
Influenza B ◽  
Fcγ Receptor ◽  
Prophylactic Efficacy ◽  
Wide Range

ABSTRACT Influenza viruses of the H1N1, H2N2, and H3N2 subtypes have caused previous pandemics. H2 influenza viruses represent a pandemic threat due to continued circulation in wild birds and limited immunity in the human population. In the event of a pandemic, antiviral agents are the mainstay for treatment, but broadly neutralizing antibodies (bNAbs) may be a viable alternative for short-term prophylaxis or treatment. The hemagglutinin stem binding bNAbs CR6261 and CR9114 have been shown to protect mice from severe disease following challenge with H1N1 and H5N1 and with H1N1, H3N2, and influenza B viruses, respectively. Early studies with CR6261 and CR9114 showed weak in vitro activity against human H2 influenza viruses, but the in vivo efficacy against H2 viruses is unknown. Therefore, we evaluated these antibodies against human- and animal-origin H2 viruses A/Ann Arbor/6/1960 (H2N2) (AA60) and A/swine/MO/4296424/06 (H2N3) (Sw06). In vitro, CR6261 neutralized both H2 viruses, while CR9114 only neutralized Sw06. To evaluate prophylactic efficacy, mice were given CR6261 or CR9114 and intranasally challenged 24 h later with lethal doses of AA60 or Sw06. Both antibodies reduced mortality, weight loss, airway inflammation, and pulmonary viral load. Using engineered bNAb variants, antibody-mediated cell cytotoxicity reporter assays, and Fcγ receptor-deficient (Fcer1g −/−) mice, we show that the in vivo efficacy of CR9114 against AA60 is mediated by Fcγ receptor-dependent mechanisms. Collectively, these findings demonstrate the in vivo efficacy of CR6261 and CR9114 against H2 viruses and emphasize the need for in vivo evaluation of bNAbs. IMPORTANCE bNAbs represent a strategy to prevent or treat infection by a wide range of influenza viruses. The evaluation of these antibodies against H2 viruses is important because H2 viruses caused a pandemic in 1957 and could cross into humans again. We demonstrate that CR6261 and CR9114 are effective against infection with H2 viruses of both human and animal origin in mice, despite the finding that CR9114 did not display in vitro neutralizing activity against the human H2 virus. These findings emphasize the importance of in vivo evaluation and testing of bNAbs.

scholarly journals Influenza B Virus NS1-Truncated Mutants: Live-Attenuated Vaccine Approach

2008 ◽  
Vol 82 (21) ◽  
pp. 10580-10590 ◽  
Author(s):  
Rong Hai ◽  
Luis Martínez-Sobrido ◽  
Kathryn A. Fraser ◽  
Juan Ayllon ◽  
Adolfo García-Sastre ◽  
...  
Keyword(s):  
Reverse Genetics ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Type I ◽  
Live Attenuated Vaccine ◽  
Live Virus ◽  
B Virus

ABSTRACT Type B influenza viruses can cause substantial morbidity and mortality in the population, and vaccination remains by far the best means of protection against infections with these viruses. Here, we report the construction of mutant influenza B viruses for potential use as improved live-virus vaccine candidates. Employing reverse genetics, we altered the NS1 gene, which encodes a type I interferon (IFN) antagonist. The resulting NS1 mutant viruses induced IFN and, as a consequence, were found to be attenuated in vitro and in vivo. The absence of pathogenicity of the NS1 mutants in both BALB/c and C57BL/6 PKR−/− mice was confirmed. We also provide evidence that influenza B virus NS1 mutants induce a self-adjuvanted immune response and confer effective protection against challenge with both homologous and heterologous B virus strains in mice.

scholarly journals Establishment of pan-Influenza A (H1-H18) and pan-Influenza B (pre-split, Vic/Yam) Pseudotype Libraries for efficient vaccine antigen selection

2021 ◽  
Author(s):  
Joanne M Del Rosario ◽  
Kelly da Costa ◽  
Benedikt Asbach ◽  
Francesca Ferrara ◽  
Matteo Ferrari ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Influenza A ◽  
Influenza Viruses ◽  
Vaccine Antigen ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Strategic Objectives ◽  
Influenza Hemagglutinin ◽  
Dosing Regimens

We have developed an influenza hemagglutinin (HA) pseudotype library encompassing Influenza A subtypes HA1-18, and Influenza B subtypes (both lineages) to be employed in influenza pseudotype microneutralization (pMN) assays. The pMN is highly sensitive and specific for de-tecting virus-specific neutralizing antibodies against influenza viruses and can be used to assess antibody functionality in vitro. Here we show the production of these viral HA pseudotypes and their employment as substitutes for wildtype viruses in influenza serological and neutralization assays. We demonstrate its utility in detecting serum response to vaccination with the ability to evaluate cross-subtype neutralizing responses elicited by specific vaccinating antigens. Our findings may inform further pre-clinical studies involving immunization dosing regimens in mice and may help in the creation and selection of better antigens for vaccine design. These HA pseudotypes can be harnessed to meet strategic objectives that contribute to the strengthening of global influenza surveillance, expansion of seasonal influenza prevention and control policies, and strengthening pandemic preparedness and response.

scholarly journals LACK OF IDENTITY IN NEUTRALIZING AND HEMAGGLUTINATION-INHIBITING ANTIBODIES AGAINST INFLUENZA VIRUSES

1950 ◽  
Vol 91 (1) ◽  
pp. 65-86 ◽  
Author(s):  
Duard L. Walker ◽  
Frank L. Horsfall
Keyword(s):  
Influenza Virus ◽  
Hemagglutination Inhibition ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Immune Serum ◽  
Influenza Viruses ◽  
In Ovo ◽  
Neutralization Line

There is an exponential linear relationship between the quantity of influenza virus neutralized and the quantity of immune serum employed in in ovo neutralization. The slope of the neutralization line is extremely steep. The concentration of neutralizing antibody can be measured with considerable precision in ovo if the constant virus-varying serum technique is utilized. The amounts of hemagglutination-inhibiting and neutralizing antibodies which are absorbed by a given quantity of influenza virus (PR8) were found to be predictable and the degree of reactivity of these two antibodies was shown to be directly related to the extent of immunization. It was demonstrated that there are marked discrepancies in correlation between antibody titers obtained by in vitro hemagglutination-inhibition and in vivo neutralization techniques and that neutralizing antibody is preferentially absorbed by a given quantity of virus. Inasmuch as the results were found not to be attributable to peculiarities of the techniques employed, it appears that the antibodies measured by hemagglutination-inhibition in vitro and by neutralization in vivo are not identical.

First exposure to the pandemic H1N1 virus induced broadly neutralizing antibodies targeting hemagglutinin head epitopes

2021 ◽  
Vol 13 (596) ◽  
pp. eabg4535
Author(s):  
Jenna J. Guthmiller ◽  
Julianna Han ◽  
Lei Li ◽  
Alec W. Freyn ◽  
Sean T. H. Liu ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Neutralizing Antibodies ◽  
Antigenic Site ◽  
Influenza Viruses ◽  
Chain Gene ◽  
Influenza B ◽  
Pandemic H1n1 ◽  
Broadly Neutralizing Antibodies ◽  
Receptor Binding Site

Broadly neutralizing antibodies are critical for protection against both drifted and shifted influenza viruses. Here, we reveal that first exposure to the 2009 pandemic H1N1 influenza virus recalls memory B cells that are specific to the conserved receptor-binding site (RBS) or lateral patch epitopes of the hemagglutinin (HA) head domain. Monoclonal antibodies (mAbs) generated against these epitopes are broadly neutralizing against H1N1 viruses spanning 40 years of viral evolution and provide potent protection in vivo. Lateral patch-targeting antibodies demonstrated near universal binding to H1 viruses, and RBS-binding antibodies commonly cross-reacted with H3N2 viruses and influenza B viruses. Lateral patch-targeting mAbs were restricted to expressing the variable heavy-chain gene VH3-23 with or without the variable kappa-chain gene VK1-33 and often had a Y-x-R motif within the heavy-chain complementarity determining region 3 to make key contacts with HA. Moreover, lateral patch antibodies that used both VH3-23 and VK1-33 maintained neutralizing capability with recent pH1N1 strains that acquired mutations near the lateral patch. RBS-binding mAbs used a diverse repertoire but targeted the RBS epitope similarly and made extensive contacts with the major antigenic site Sb. Together, our data indicate that RBS- and lateral patch-targeting clones are abundant within the human memory B cell pool, and universal vaccine strategies should aim to drive antibodies against both conserved head and stalk epitopes.

scholarly journals Exploiting Pan Influenza A and Pan Influenza B Pseudotype Libraries for Efficient Vaccine Antigen Selection

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 741
Author(s):  
Joanne Marie M. Del Rosario ◽  
Kelly A. S. da Costa ◽  
Benedikt Asbach ◽  
Francesca Ferrara ◽  
Matteo Ferrari ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Influenza A ◽  
Influenza Viruses ◽  
Vaccine Antigen ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Strategic Objectives ◽  
Influenza Hemagglutinin ◽  
Dosing Regimens

We developed an influenza hemagglutinin (HA) pseudotype library encompassing Influenza A subtypes HA1-18 and Influenza B subtypes (both lineages) to be employed in influenza pseudotype microneutralization (pMN) assays. The pMN is highly sensitive and specific for detecting virus-specific neutralizing antibodies against influenza viruses and can be used to assess antibody functionality in vitro. Here we show the production of these viral HA pseudotypes and their employment as substitutes for wildtype viruses in influenza neutralization assays. We demonstrate their utility in detecting serum responses to vaccination with the ability to evaluate cross-subtype neutralizing responses elicited by specific vaccinating antigens. Our findings may inform further preclinical studies involving immunization dosing regimens in mice and may help in the creation and selection of better antigens for vaccine design. These HA pseudotypes can be harnessed to meet strategic objectives that contribute to the strengthening of global influenza surveillance, expansion of seasonal influenza prevention and control policies, and strengthening pandemic preparedness and response.

scholarly journals Inhibitory effects of aprotinin on influenza A and B viruses in vitro and in vivo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eun-Jung Song ◽  
Erica Españo ◽  
Sang-Mu Shim ◽  
Jeong-Hyun Nam ◽  
Jiyeon Kim ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Lethal Dose ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Inhibitory Effects ◽  
Compound Libraries ◽  
Wide Range

AbstractInfluenza viruses cause significant morbidity and mortality worldwide. Long-term or frequent use of approved anti-influenza agents has resulted in drug-resistant strains, thereby necessitating the discovery of new drugs. In this study, we found aprotinin, a serine protease inhibitor, as an anti-influenza candidate through screening of compound libraries. Aprotinin has been previously reported to show inhibitory effects on a few influenza A virus (IAV) subtypes (e.g., seasonal H1N1 and H3N2). However, because there were no reports of its inhibitory effects on the other types of influenza viruses, we investigated the inhibitory effects of aprotinin in vitro on a wide range of influenza viruses, including avian and oseltamivir-resistant influenza virus strains. Our cell-based assay showed that aprotinin had inhibitory effects on seasonal human IAVs (H1N1 and H3N2 subtypes), avian IAVs (H5N2, H6N5, and H9N2 subtypes), an oseltamivir-resistant IAV, and a currently circulating influenza B virus. We have also confirmed its activity in mice infected with a lethal dose of influenza virus, showing a significant increase in survival rate. Our findings suggest that aprotinin has the capacity to inhibit a wide range of influenza virus subtypes and should be considered for development as a therapeutic agent against influenza.

scholarly journals Transthyretin Stabilization: An Emerging Strategy for the Treatment of Alzheimer’s Disease?

2020 ◽  
Vol 21 (22) ◽  
pp. 8672
Author(s):  
Federica Saponaro ◽  
Jin Hae Kim ◽  
Grazia Chiellini
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Severe Disease ◽  
In Vivo Studies ◽  
Neuroprotective Effects ◽  
Transthyretin Amyloidosis ◽  
Wide Range ◽  
Clinical Series

Transthyretin (TTR), previously named prealbumin is a plasma protein secreted mainly by the liver and choroid plexus (CP) that is a carrier for thyroid hormones (THs) and retinol (vitamin A). The structure of TTR, with four monomers rich in β-chains in a globular tetrameric protein, accounts for the predisposition of the protein to aggregate in fibrils, leading to a rare and severe disease, namely transthyretin amyloidosis (ATTR). Much effort has been made and still is required to find new therapeutic compounds that can stabilize TTR (“kinetic stabilization”) and prevent the amyloid genetic process. Moreover, TTR is an interesting therapeutic target for neurodegenerative diseases due to its recognized neuroprotective properties in the cognitive impairment context and interestingly in Alzheimer’s disease (AD). Much evidence has been collected regarding the neuroprotective effects in AD, including through in vitro and in vivo studies as well as a wide range of clinical series. Despite this supported hypothesis of neuroprotection for TTR, the mechanisms are still not completely clear. The aim of this review is to highlight the most relevant findings on the neuroprotective role of TTR, and to summarize the recent progress on the development of TTR tetramer stabilizers.

scholarly journals The Ability of Porcine Reproductive and Respiratory Syndrome Virus Isolates to Induce Broadly Reactive Neutralizing Antibodies Correlates With In Vivo Protection

2021 ◽  
Vol 12 ◽  
Author(s):  
Francisco Javier Martínez-Lobo ◽  
Francisco Díez-Fuertes ◽  
Isabel Simarro ◽  
José M. Castro ◽  
Cinta Prieto
Keyword(s):  
Neutralizing Antibodies ◽  
Respiratory Syndrome Virus ◽  
Partial Protection ◽  
Challenge Virus ◽  
Prrs Virus ◽  
Wide Range ◽  
Sterilizing Immunity ◽  
Virus Isolates

Porcine reproductive and respiratory syndrome (PRRS) is considered one of the most relevant diseases of swine. The condition is caused by PRRS virus (PRRSV), an extremely variable virus of the Arteriviridae family. Its heterogeneity can be responsible, at least partially, of the poor cross-protection observed between PRRSV isolates. Neutralizing antibodies (NAs), known to play a role in protection, usually poorly recognize heterologous PRRSV isolates, indicating that most NAs are strain-specific. However, some pigs develop broadly reactive NAs able to recognize a wide range of heterologous isolates. The aim of this study was to determine whether PRRSV isolates that induce broadly reactive NAs as determined in vitro are able to confer a better protection in vivo. For this purpose two in vivo experiments were performed. Initially, 40 pigs were immunized with a PRRSV-1 isolate known to induce broadly reactive NAs and 24 additional pigs were used as controls. On day 70 after immunization, the pigs were divided into eight groups composed by five immunized and three control pigs and exposed to one of the eight different heterologous PRRSV isolates used for the challenge. In the second experiment, the same experimental design was followed but the pigs were immunized with a PRRSV-1 isolate, which is known to generate mostly strain-specific NAs. Virological parameters, specifically viremia and the presence of challenge virus in tonsils, were used to determine protection. In the first experiment, sterilizing immunity was obtained in three groups, prevention of viremia was observed in two additional groups, although the challenge virus was detected occasionally in the tonsils of immunized pigs, and partial protection, understood as a reduction in the frequency of viremia compared with controls, was recorded in the remaining three groups. On the contrary, only partial protection was observed in all groups in the second experiment. The results obtained in this study confirm that PRRSV-1 isolates differ in their ability to induce cross-reactive NAs and, although other components of the immune response might have contributed to protection, pigs with cross-reactive NAs at the time of challenge exhibited better protection, indicating that broadly reactive NAs might play a role in protection against heterologous reinfections.

scholarly journals A New Master Donor Virus for the Development of Live-Attenuated Influenza B Virus Vaccines

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1278
Author(s):  
Chantelle L. White ◽  
Kevin Chiem ◽  
Daniel R. Perez ◽  
Jefferson Santos ◽  
Stivalis Cardenas Garcia ◽  
...  
Keyword(s):  
The Elderly ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Temperature Sensitive ◽  
Direct Exposure ◽  
Variable Surface ◽  
Ann Arbor

Influenza B viruses (IBV) circulate annually, with young children, the elderly and immunocompromised individuals being at high risk. Yearly vaccinations are recommended to protect against seasonally influenza viruses, including IBV. Live attenuated influenza vaccines (LAIV) provide the unique opportunity for direct exposure to the antigenically variable surface glycoproteins as well as the more conserved internal components. Ideally, LAIV Master Donor Viruses (MDV) should accurately reflect seasonal influenza strains. Unfortunately, the continuous evolution of IBV have led to significant changes in conserved epitopes compared to the IBV MDV based on B/Ann Arbor/1/1966 strain. Here, we propose a recent influenza B/Brisbane/60/2008 as an efficacious MDV alternative, as its internal viral proteins more accurately reflect those of circulating IBV strains. We introduced the mutations responsible for the temperature sensitive (ts), cold adapted (ca) and attenuated (att) phenotype of B/Ann Arbor/1/1966 MDV LAIV into B/Brisbane/60/2008 to generate a new MDV LAIV. In vitro and in vivo analysis demonstrated that the mutations responsible of the ts, ca, and att phenotype of B/Ann Arbor/1/1966 MDV LAIV were able to infer the same phenotype to B/Brisbane/60/2008, demonstrating its potential as a new MDV for the development of LAIV to protect against contemporary IBV strains.

scholarly journals Chaiqin Qingning Capsule Inhibits Influenza Virus Infection and Inflammation In Vitro and In Vivo

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jin Zhao ◽  
Yanbing Hao ◽  
Xuanzi Xia ◽  
Runfeng Li ◽  
Xiaodong Huang ◽  
...  
Keyword(s):  
Influenza Virus ◽  
A549 Cells ◽  
Influenza Virus Infection ◽  
Influenza Viruses ◽  
Dependent Manner ◽  
Lung Pathology ◽  
Chemokine Expression ◽  
Wide Range

Background. Chaiqin Qingning Capsule (CQ-C) is a traditional Chinese medicine (TCM) formula commonly used to treat respiratory infectious diseases in China. The aim of this study was to detect the effect and mechanism of CQ-C treated with influenza virus in vitro and vivo. Methods. The cytotoxicity and antiviral activity of CQ-C in vitro was determined by methyl thiazolyl tetrazolium (MTT) assay. The regulation of CQ-C on cytokine/chemokine expression was evaluated using RT-qPCR. In addition, the effect of CQ-C on the pathway protein, NF-κB, and its phosphorylation level was verified by western blotting. After virus inoculation, BALB/c mice were administered with CQ-C of different concentrations for 7 days. Body weight, viral titer, lung pathology, and mortality of the mice were measured, and the level of inflammatory cytokines was also examined using real-time RT-qPCR. Results. CQ-C inhibited the proliferation of influenza virus of various strains in vitro, with the 50% inhibitory concentration (IC50) ranging from 49 to 59 µg/mL. CQ-C downregulated virus-induced gene expression of IL-6, TNF-α, CXCL8, CXCL10, CCL5, and COX-2 in a dose-dependent manner in A549 cells. Also, CQ-C inhibited the expression of NF-κB protein of the signaling pathway. Moreover, a decrease of the lung index and mortality of mice was observed in the CQ-C (1 g/kg/d) group. The related cytokine/chemokine expression was also decreased in the early stages of infection in the mRNA level. Conclusion. As a clinically applied Chinese prescription, our study shows that CQ-C has a wide range of effects on several influenza viruses. Moreover, CQ-C could play an important role in anti-influenza activity and anti-inflammation in vitro and in vivo. Thus, CQ-C may be a promising treatment option for influenza.

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