scholarly journals Pan-ebolavirus and Pan-filovirus Mouse Monoclonal Antibodies: Protection against Ebola and Sudan Viruses

2015 ◽  
Vol 90 (1) ◽  
pp. 266-278 ◽  
Author(s):  
Frederick W. Holtsberg ◽  
Sergey Shulenin ◽  
Hong Vu ◽  
Katie A. Howell ◽  
Sonal J. Patel ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Rational Design ◽  
Ebola Virus ◽  
Immune Cell ◽  
Virus Disease ◽  
Protective Efficacy ◽  
Neutralizing Antibody ◽  
Cross Reactivity ◽  
Virus Species

ABSTRACTThe unprecedented 2014-2015 Ebola virus disease (EVD) outbreak in West Africa has highlighted the need for effective therapeutics against filoviruses. Monoclonal antibody (MAb) cocktails have shown great potential as EVD therapeutics; however, the existing protective MAbs are virus species specific. Here we report the development of pan-ebolavirus and pan-filovirus antibodies generated by repeated immunization of mice with filovirus glycoproteins engineered to drive the B cell responses toward conserved epitopes. Multiple pan-ebolavirus antibodies were identified that react to the Ebola, Sudan, Bundibugyo, and Reston viruses. A pan-filovirus antibody that was reactive to the receptor binding regions of all filovirus glycoproteins was also identified. Significant postexposure efficacy of several MAbs, including a novel antibody cocktail, was demonstrated. For the first time, we report cross-neutralization andin vivoprotection against two highly divergent filovirus species, i.e., Ebola virus and Sudan virus, with a single antibody. Competition studies indicate that this antibody targets a previously unrecognized conserved neutralizing epitope that involves the glycan cap. Mechanistic studies indicated that, besides neutralization, innate immune cell effector functions may play a role in the antiviral activity of the antibodies. Our findings further suggest critical novel epitopes that can be utilized to design effective cocktails for broad protection against multiple filovirus species.IMPORTANCEFiloviruses represent a major public health threat in Africa and an emerging global concern. Largely driven by the U.S. biodefense funding programs and reinforced by the 2014 outbreaks, current immunotherapeutics are primarily focused on a single filovirus species called Ebola virus (EBOV) (formerly Zaire Ebola virus). However, other filoviruses including Sudan, Bundibugyo, and Marburg viruses have caused human outbreaks with mortality rates as high as 90%. Thus, cross-protective immunotherapeutics are urgently needed. Here, we describe monoclonal antibodies with cross-reactivity to several filoviruses, including the first report of a cross-neutralizing antibody that exhibits protection against Ebola virus and Sudan virus in mice. Our results further describe a novel combination of antibodies with enhanced protective efficacy. These results form a basis for further development of effective immunotherapeutics against filoviruses for human use. Understanding the cross-protective epitopes are also important for rational design of pan-ebolavirus and pan-filovirus vaccines.

scholarly journals Macaque Monoclonal Antibodies Targeting Novel Conserved Epitopes within Filovirus Glycoprotein

2015 ◽  
Vol 90 (1) ◽  
pp. 279-291 ◽  
Author(s):  
Zhen-Yong Keck ◽  
Sven G. Enterlein ◽  
Katie A. Howell ◽  
Hong Vu ◽  
Sergey Shulenin ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Nonhuman Primates ◽  
Ebola Virus ◽  
Virus Disease ◽  
Protective Efficacy ◽  
Hemorrhagic Fever ◽  
Marburg Virus ◽  
Human Pathogens ◽  
Content Type ◽  
The Core

ABSTRACTFiloviruses cause highly lethal viral hemorrhagic fever in humans and nonhuman primates. Current immunotherapeutic options for filoviruses are mostly specific to Ebola virus (EBOV), although other members ofFiloviridaesuch as Sudan virus (SUDV), Bundibugyo virus (BDBV), and Marburg virus (MARV) have also caused sizeable human outbreaks. Here we report a set of pan-ebolavirus and pan-filovirus monoclonal antibodies (MAbs) derived from cynomolgus macaques immunized repeatedly with a mixture of engineered glycoproteins (GPs) and virus-like particles (VLPs) for three different filovirus species. The antibodies recognize novel neutralizing and nonneutralizing epitopes on the filovirus glycoprotein, including conserved conformational epitopes within the core regions of the GP1 subunit and a novel linear epitope within the glycan cap. We further report the first filovirus antibody binding to a highly conserved epitope within the fusion loop of ebolavirus and marburgvirus species. One of the antibodies binding to the core GP1 region of all ebolavirus species and with lower affinity to MARV GP cross neutralized both SUDV and EBOV, the most divergent ebolavirus species. In a mouse model of EBOV infection, this antibody provided 100% protection when administered in two doses and partial, but significant, protection when given once at the peak of viremia 3 days postinfection. Furthermore, we describe novel cocktails of antibodies with enhanced protective efficacy compared to individual MAbs. In summary, the present work describes multiple novel, cross-reactive filovirus epitopes and innovative combination concepts that challenge the current therapeutic models.IMPORTANCEFiloviruses are among the most deadly human pathogens. The 2014-2015 outbreak of Ebola virus disease (EVD) led to more than 27,000 cases and 11,000 fatalities. While there are five species ofEbolavirusand several strains of marburgvirus, the current immunotherapeutics primarily target Ebola virus. Since the nature of future outbreaks cannot be predicted, there is an urgent need for therapeutics with broad protective efficacy against multiple filoviruses. Here we describe a set of monoclonal antibodies cross-reactive with multiple filovirus species. These antibodies target novel conserved epitopes within the envelope glycoprotein and exhibit protective efficacy in mice. We further present novel concepts for combination of cross-reactive antibodies against multiple epitopes that show enhanced efficacy compared to monotherapy and provide complete protection in mice. These findings set the stage for further evaluation of these antibodies in nonhuman primates and development of effective pan-filovirus immunotherapeutics for use in future outbreaks.

scholarly journals Mechanism of Binding to Ebola Virus Glycoprotein by the ZMapp, ZMAb, and MB-003 Cocktail Antibodies

2015 ◽  
Vol 89 (21) ◽  
pp. 10982-10992 ◽  
Author(s):  
Edgar Davidson ◽  
Christopher Bryan ◽  
Rachel H. Fong ◽  
Trevor Barnes ◽  
Jennifer M. Pfaff ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Ebola Virus ◽  
Therapeutic Potential ◽  
Virus Disease ◽  
Surface Glycoprotein ◽  
Alanine Scanning Mutagenesis ◽  
Treatment Protocols ◽  
Apparent Affinity ◽  
Binding Characteristics

ABSTRACTCocktails of monoclonal antibodies (MAbs) that target the surface glycoprotein (GP) of Ebola virus (EBOV) are effective in nonhuman primate models and have been used under emergency compassionate-treatment protocols in human patients. However, the amino acids that form the detailed binding epitopes for the MAbs in the ZMapp, ZMAb, and the related MB-003 cocktails have yet to be identified. Other binding properties that define how each MAb functionally interacts with GP—such as affinity, epitope conservation, and epitope accessibility—also remain largely unknown. To help define how each MAb interacts with GP, here we used comprehensive alanine-scanning mutagenesis (shotgun mutagenesis), neutralization escape, and whole virion binding to define each MAb's specific epitope, epitope accessibility, epitope conservation, and apparent affinity. Each of the six therapeutic MAbs binds nonidentical epitopes in the GP base, glycan cap, or mucin-like domain. Their apparent affinity, epitope complementarity, and epitope accessibility helps explain why MAbs 4G7 and 13C6 are more protective than 2G4 and 1H3. The mucin-like domain MAbs 6D8 and 13F6 bind with the strongest apparent affinity, helping to explain their effectivenessin vivodespite their inability to neutralize virus.IMPORTANCEEbola virus disease (EVD) can be caused by four different filovirus family members, including Ebola virus (EBOV), which infected 10 times more people in western Africa over the last year than all previous EVD outbreaks combined, with a number of cases distributed across the globe by travelers. Cocktails of inhibitory monoclonal antibodies (MAbs), such as ZMAb, MB-003, and in particular ZMapp, have demonstrated in animal models some of the most significant therapeutic potential for treating EVD, and in 2014, 15 patients were treated with ZMapp or ZMAb under compassionate-use protocols. Here, we have defined the epitope features for the most important therapeutic MAbs against EBOV developed to date. Defining the epitopes and binding characteristics for these MAbs, as well as the commonly used reference MAb KZ52, helps explain their breadth of reactivity against different ebolavirus species, predict viral evasion against these MAbs, and design new cocktails of MAbs with improved complementarity.

scholarly journals Exacerbation of Influenza A Virus Disease Severity by Respiratory Syncytial Virus Co-Infection in a Mouse Model

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1630 ◽  
Author(s):  
Junu A. George ◽  
Shaikha H. AlShamsi ◽  
Maryam H. Alhammadi ◽  
Ahmed R. Alsuwaidi
Keyword(s):  
T Cells ◽  
Respiratory Syncytial Virus ◽  
Influenza A Virus ◽  
Influenza A ◽  
Immune Cell ◽  
Virus Disease ◽  
Viral Loads ◽  
Syncytial Virus

Influenza A virus (IAV) and respiratory syncytial virus (RSV) are leading causes of childhood infections. RSV and influenza are competitive in vitro. In this study, the in vivo effects of RSV and IAV co-infection were investigated. Mice were intranasally inoculated with RSV, with IAV, or with both viruses (RSV+IAV and IAV+RSV) administered sequentially, 24 h apart. On days 3 and 7 post-infection, lung tissues were processed for viral loads and immune cell populations. Lung functions were also evaluated. Mortality was observed only in the IAV+RSV group (50% of mice did not survive beyond 7 days). On day 3, the viral loads in single-infected and co-infected mice were not significantly different. However, on day 7, the IAV titer was much higher in the IAV+RSV group, and the RSV viral load was reduced. CD4 T cells were reduced in all groups on day 7 except in single-infected mice. CD8 T cells were higher in all experimental groups except the RSV-alone group. Increased airway resistance and reduced thoracic compliance were demonstrated in both co-infected groups. This model indicates that, among all the infection types we studied, infection with IAV followed by RSV is associated with the highest IAV viral loads and the most morbidity and mortality.

scholarly journals Rational design of peptides for identification of linear epitopes and generation of neutralizing monoclonal antibodies against DKK2 for cancer therapy

2020 ◽  
Vol 3 (2) ◽  
pp. 63-70 ◽  
Author(s):  
Rongqing Zhao ◽  
Qian Xiao ◽  
Maohua Li ◽  
Wenlin Ren ◽  
Chenxi Xia ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Growth ◽  
Wnt Signaling ◽  
Rational Design ◽  
Polyclonal Antibodies ◽  
Wnt Signaling Pathway ◽  
Keyhole Limpet Hemocyanin ◽  
Linear Epitopes

Abstract Dickkopf-related protein 2 (DKK2)is a member of the Dickkopf family in Wnt signaling pathway. Recently, we found that antibodies against DKK2 could activate natural killer (NK) and CD8+ T cells in tumors and inhibit tumor growth. In this paper, we report the rational design of peptides for identification of linear epitopes and generation of neutralizing monoclonal anti-DKK2 antibodies. To break the immune tolerance, we designed and chemically synthesized six peptides corresponding to different regions of DKK2 as immunogens and found five of them could generate mouse polyclonal antibodies that can bind to the active recombinant human DKK2 protein. Neutralizing mouse monoclonal antibodies (5F8 and 1A10) against human DKK2 were successfully developed by immunizing the mice with two different peptides (34KLNSIKSSL42 and 240KVWKDATYS248) conjugated to Keyhole limpet hemocyanin (KLH). The monoclonal antibodies not only abolish DKK2’s suppression of Wnt signaling in vitro but also inhibits tumor growth in vivo. Currently, those two mAbs are undergoing humanization as immunotherapy candidates and may offer a new drug for treatment of human cancers.

scholarly journals Novel Cross-Reactive Monoclonal Antibodies against Ebolavirus Glycoproteins Show Protection in a Murine Challenge Model

2017 ◽  
Vol 91 (16) ◽  
Author(s):  
James Duehr ◽  
Teddy John Wohlbold ◽  
Lisa Oestereich ◽  
Veronika Chromikova ◽  
Fatima Amanat ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Vesicular Stomatitis Virus ◽  
Viral Vector ◽  
Virus Disease ◽  
Protective Efficacy ◽  
Influenza Viruses ◽  
Content Type ◽  
Zaire Ebolavirus ◽  
Vesicular Stomatitis

ABSTRACT Out of an estimated 31,100 cases since their discovery in 1976, ebolaviruses have caused approximately 13,000 deaths. The vast majority (∼11,000) of these occurred during the 2013-2016 West African epidemic. Three out of five species in the genus are known to cause Ebola Virus Disease in humans. Several monoclonal antibodies against the ebolavirus glycoprotein are currently in development as therapeutics. However, there is still a paucity of monoclonal antibodies that can cross-react between the glycoproteins of different ebolavirus species, and the mechanism of these monoclonal antibody therapeutics is still not understood in detail. Here, we generated a panel of eight murine monoclonal antibodies (MAbs) utilizing a prime-boost vaccination regimen with a Zaire ebolavirus glycoprotein expression plasmid followed by infection with a vesicular stomatitis virus expressing the Zaire ebolavirus glycoprotein. We tested the binding breadth of the resulting monoclonal antibodies using a set of recombinant surface glycoproteins from Reston, Taï Forest, Bundibugyo, Zaire, Sudan, and Marburg viruses and found two antibodies that showed pan-ebolavirus binding. An in vivo Stat2 −/− mouse model was utilized to test the ability of these MAbs to protect from infection with a vesicular stomatitis virus expressing the Zaire ebolavirus glycoprotein. Several of our antibodies, including the broadly binding ones, protected mice from mortality despite lacking neutralization capability in vitro, suggesting their protection may be mediated by Fc-FcR interactions. Indeed, three antibodies displayed cellular phagocytosis and/or antibody-dependent cell-mediated cytotoxicity in vitro. Our antibodies, specifically the two identified cross-reactive monoclonal antibodies (KL-2E5 and KL-2H7), might add to the understanding of anti-ebolavirus humoral immunity. IMPORTANCE This study describes the generation of a panel of novel anti-ebolavirus glycoprotein monoclonal antibodies, including two antibodies with broad cross-reactivity to all known ebolavirus species. The antibodies were raised using a heterologous DNA-viral vector prime-boost regimen, resulting in a high proportion of cross-reactive antibodies (25%). Similar vaccination regimens have been used successfully to induce broad protection against influenza viruses in humans, and our limited data indicate that this might be a useful strategy for filovirus vaccines as well. Several of our antibodies showed protective efficacy when tested in a novel murine challenge model and may be developed into future therapeutics.

scholarly journals Method for the Selective Measurement of Amino-Terminal Variants of Procalcitonin

2009 ◽  
Vol 55 (9) ◽  
pp. 1672-1679 ◽  
Author(s):  
Joachim Struck ◽  
Martina Strebelow ◽  
Sonja Tietz ◽  
Christine Alonso ◽  
Nils G Morgenthaler ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Bacterial Infections ◽  
Cross Reactivity ◽  
Functional Assay ◽  
Human Endotoxemia ◽  
Amino Terminal ◽  
Endotoxemia Model ◽  
Sandwich Assays ◽  
Kinetics Of

Abstract Background: Procalcitonin (PCT) is an established marker for diagnosing and monitoring bacterial infections. Full-length PCT [116 amino acids that make up procalcitonin (PCT1–116)] can be truncated, leading to des-Ala-Pro-PCT (des-Alanin-Prolin-Procalcitonin; PCT3–116). Current immunoassays for PCT (“total PCT”) use antibodies directed against internal epitopes and are unable to distinguish amino-terminal PCT variants. Here we describe the development of monoclonal antibodies recognizing the amino-termini of PCT1–116 and PCT3–116 and their use in the selective measurement of these PCT species. Methods: With newly developed monoclonal antibodies against the amino-termini of PCT1–116 and PCT3–116, and an antibody against the katacalcin moiety of PCT, we developed and characterized immunoluminometric assays for the 2 PCT peptides. We comparatively assessed the kinetics of PCT variants in a human endotoxemia model. Results: Monoclonal antibodies against the amino-termini of PCT1–116 and PCT3–116 showed <1% cross-reactivity with other PCT-related peptides. The sandwich assays for PCT1–116 and PCT3–116 had functional assay sensitivities of 5 and 1.2 pmol/L, respectively, and exhibited recoveries within 20% of expected values. Plasma PCT1–116 was stable for 6 h at 22 °C and 24 h at 4 °C, and PCT3–116 was stable for at least 24 h at both temperatures. During experimental endotoxemia in healthy people, both PCT1–116 and PCT3–116 increased early in parallel with total PCT, but further increases in PCT1–116 were significantly slower than for PCT3–116 (P = 0.0049) and total PCT (P = 0.0024). Conclusions: The new assays selectively measure PCT1–116 and PCT3–116. Both PCT species increase early during endotoxemia but differ in their kinetics thereafter. The selective measurement of PCT species with different in vivo kinetics may be useful in improving PCT-guided therapies.

scholarly journals Potential human immunotherapeutics for plague

2021 ◽  
Author(s):  
Voahangy Andrianaivoarimanana ◽  
Lovasoa Nomena Randriantseheno ◽  
Kristoffer M Moore ◽  
Nicola J Walker ◽  
Steven G Lonsdale ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
South America ◽  
Yersinia Pestis ◽  
Clinical Isolate ◽  
Murine Model ◽  
Post Infection ◽  
Protective Efficacy ◽  
First Time ◽  
A Current

Abstract Two monoclonal antibodies directed to the V antigen of Yersinia pestis have been tested for protective efficacy in a murine model of bubonic plague. Mice were infected with a current clinical isolate from Madagascar, designated Y.pestis 10-21/S. Mab7.3, delivered to mice intra-periteoneally at either 24h prior to, or 24h post- infection, was fully protective, building on many studies which have demonstrated the protective efficacy of this Mab against a number of different clinical isolates of Y.pestis. Mab 29.3, delivered intra-peritoneally at either -24h or +24h, protected 4/5 mice in either condition; this has demonstrated the protective efficacy of this Mab in vivo for the first time. These results add to the cumulative data about Mab7.3, which is currently being humanized and highlight its potential as a human immunotherapeutic for plague, which is an enduring endemic disease in Madagascar and other regions of Africa, Asia and South America.

scholarly journals Effect of RBD mutation (Y453F) in spike glycoprotein of SARS-CoV-2 on neutralizing antibody affinity

2020 ◽  
Author(s):  
Takuma Hayashi ◽  
Nobuo Yaegashi ◽  
Ikuo Konishi
Keyword(s):  
Experimental Study ◽  
Monoclonal Antibodies ◽  
Natural Selection ◽  
Structural Analysis ◽  
Growth Process ◽  
Three Dimensional ◽  
Neutralizing Antibody ◽  
Antibody Affinity ◽  
Protein Structural Analysis

AbstractNatural selection “adaptation” in the coronavirus can occur during coronavirus amplification in vivo in farmed minks. Natural selection in such viruses is observed by introduction of mutations in SARS- CoV-2 that are not observed during the growth process in humans. Infection with a mutant (Y453F) of SARS-CoV-2 from farmed minks is known to widely spread among humans. We investigated the virological characteristics of this SARS-CoV-2 mutant (Y453F) using three-dimensional protein structural analysis. Our experimental study suggests that virus variants with the Y453F mutation partially escaped detection by four neutralizing monoclonal antibodies. The spread of SARS-CoV-2 variants mediated by millions of infected farmed minks is uncontrolled; consequently, raising a concern that infection of SARS-CoV-2 mutants that cause serious symptoms in humans may spread globally.

scholarly journals Development of an antibody cocktail for treatment of Sudan virus infection

2020 ◽  
Vol 117 (7) ◽  
pp. 3768-3778 ◽  
Author(s):  
Andrew S. Herbert ◽  
Jeffery W. Froude ◽  
Ramon A. Ortiz ◽  
Ana I. Kuehne ◽  
Danielle E. Dorosky ◽  
...  
Keyword(s):  
Treatment Option ◽  
Ebola Virus ◽  
Protective Efficacy ◽  
Rhesus Macaques ◽  
Macaque Model ◽  
Mammalian Expression ◽  
Significant Difference ◽  
Antibody Cocktail

Antibody-based therapies are a promising treatment option for managing ebolavirus infections. Several Ebola virus (EBOV)-specific and, more recently, pan-ebolavirus antibody cocktails have been described. Here, we report the development and assessment of a Sudan virus (SUDV)-specific antibody cocktail. We produced a panel of SUDV glycoprotein (GP)-specific human chimeric monoclonal antibodies (mAbs) using both plant and mammalian expression systems and completed head-to-head in vitro and in vivo evaluations. Neutralizing activity, competitive binding groups, and epitope specificity of SUDV mAbs were defined before assessing protective efficacy of individual mAbs using a mouse model of SUDV infection. Of the mAbs tested, GP base-binding mAbs were more potent neutralizers and more protective than glycan cap- or mucin-like domain-binding mAbs. No significant difference was observed between plant and mammalian mAbs in any of our in vitro or in vivo evaluations. Based on in vitro and rodent testing, a combination of two SUDV-specific mAbs, one base binding (16F6) and one glycan cap binding (X10H2), was down-selected for assessment in a macaque model of SUDV infection. This cocktail, RIID F6-H2, provided protection from SUDV infection in rhesus macaques when administered at 50 mg/kg on days 4 and 6 postinfection. RIID F6-H2 is an effective postexposure SUDV therapy and provides a potential treatment option for managing human SUDV infection.

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