scholarly journals Rational design of universal immunotherapy for TfR1-tropic arenaviruses

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Hadas Cohen-Dvashi ◽  
Ron Amon ◽  
Krystle N. Agans ◽  
Robert W. Cross ◽  
Aliza Borenstein-Katz ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Rational Design ◽  
Biological Weapons ◽  
Hemorrhagic Fevers ◽  
Transferrin Receptor 1 ◽  
Viral Glycoproteins ◽  
Life Threatening ◽  
Pathogenic Viruses ◽  
Rodent Populations ◽  
Reactive Molecule

AbstractCertain arenaviruses that circulate in rodent populations can cause life-threatening hemorrhagic fevers when they infect humans. Due to their efficient transmission, arenaviruses pose a severe risk for outbreaks and might be exploited as biological weapons. Effective countermeasures against these viruses are highly desired. Ideally, a single remedy would be effective against many or even all the pathogenic viruses in this family. However, despite the fact that all pathogenic arenaviruses from South America utilize transferrin receptor 1 (TfR1) as a cellular receptor, their viral glycoproteins are highly diversified, impeding efforts to isolate cross-neutralizing antibodies. Here we address this problem using a rational design approach to target TfR1-tropic arenaviruses with high potency and breadth. The pan-reactive molecule is highly effective against all arenaviruses that were tested, offering a universal therapeutic approach. Our design scheme avoids the shortcomings of previous immunoadhesins and can be used to combat other zoonotic pathogens.

scholarly journals New World Clade B Arenaviruses Can Use Transferrin Receptor 1 (TfR1)-Dependent and -Independent Entry Pathways, and Glycoproteins from Human Pathogenic Strains Are Associated with the Use of TfR1

2007 ◽  
Vol 82 (2) ◽  
pp. 938-948 ◽  
Author(s):  
Meg L. Flanagan ◽  
Jill Oldenburg ◽  
Therese Reignier ◽  
Nathalia Holt ◽  
Genevieve A. Hamilton ◽  
...  
Keyword(s):  
Transferrin Receptor ◽  
New World ◽  
Lassa Fever ◽  
Human Pathogens ◽  
Hemorrhagic Fevers ◽  
Clade B ◽  
Transferrin Receptor 1 ◽  
The Family ◽  
Lassa Fever Virus ◽  
Pathogenic Viruses

ABSTRACT Arenaviruses are rodent-borne viruses, with five members of the family capable of causing severe hemorrhagic fevers if transmitted to humans. To date, two distinct cellular receptors have been identified that are used by different pathogenic viruses, α-dystroglycan by Lassa fever virus and transferrin receptor 1 (TfR1) by certain New World clade B viruses. Our previous studies have suggested that other, as-yet-unknown receptors are involved in arenavirus entry. In the present study, we examined the use of TfR1 by the glycoproteins (GPs) from a panel of New World clade B arenaviruses comprising three pathogenic and two nonpathogenic strains. Interestingly, we found that TfR1 was only used by the GPs from the pathogenic viruses, with entry of the nonpathogenic strains being TfR1 independent. The pathogenic GPs could also direct entry into cells by TfR1-independent pathways, albeit less efficiently. A comparison of the abilities of TfR1 orthologs from different species to support arenavirus entry found that the human and feline receptors were able to enhance entry of the pathogenic strains, but that neither the murine or canine forms were functional. Since the ability to use TfR1 is a characteristic feature of the human pathogens, this interaction may represent an important target in the treatment of New World hemorrhagic fevers. In addition, the ability to use TfR1 may be a useful tool to predict the likelihood that any existing or newly discovered viruses in this family could infect humans.

scholarly journals SARS-CoV-2 Cellular Infection and Therapeutic Opportunities: Lessons Learned from Ebola Virus

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 64
Author(s):  
Jordana Muñoz-Basagoiti ◽  
Daniel Perez-Zsolt ◽  
Jorge Carrillo ◽  
Julià Blanco ◽  
Bonaventura Clotet ◽  
...  
Keyword(s):  
Viral Entry ◽  
Ebola Virus ◽  
Lessons Learned ◽  
Productive Infection ◽  
Target Cells ◽  
Emerging Viruses ◽  
Highly Pathogenic ◽  
Life Threatening ◽  
Pathogenic Viruses ◽  
Cellular Machinery

Viruses rely on the cellular machinery to replicate and propagate within newly infected individuals. Thus, viral entry into the host cell sets up the stage for productive infection and disease progression. Different viruses exploit distinct cellular receptors for viral entry; however, numerous viral internalization mechanisms are shared by very diverse viral families. Such is the case of Ebola virus (EBOV), which belongs to the filoviridae family, and the recently emerged coronavirus SARS-CoV-2. These two highly pathogenic viruses can exploit very similar endocytic routes to productively infect target cells. This convergence has sped up the experimental assessment of clinical therapies against SARS-CoV-2 previously found to be effective for EBOV, and facilitated their expedited clinical testing. Here we review how the viral entry processes and subsequent replication and egress strategies of EBOV and SARS-CoV-2 can overlap, and how our previous knowledge on antivirals, antibodies, and vaccines against EBOV has boosted the search for effective countermeasures against the new coronavirus. As preparedness is key to contain forthcoming pandemics, lessons learned over the years by combating life-threatening viruses should help us to quickly deploy effective tools against novel emerging viruses.

scholarly journals Successful Management of Acquired Hemophilia A Associated with Bullous Pemphigoid: A Case Report and Review of the Literature

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Quentin Binet ◽  
Catherine Lambert ◽  
Laurine Sacré ◽  
Stéphane Eeckhoudt ◽  
Cedric Hermans
Keyword(s):  
Bullous Pemphigoid ◽  
Neutralizing Antibodies ◽  
Hemophilia A ◽  
Rare Condition ◽  
Term Treatment ◽  
Acquired Hemophilia A ◽  
Acquired Hemophilia ◽  
Short Term Treatment ◽  
Life Threatening ◽  
Dose Levels

Background. Acquired hemophilia A (AHA) is a rare condition, due to the spontaneous formation of neutralizing antibodies against endogenous factor VIII. About half the cases are associated with pregnancy, postpartum, autoimmune diseases, malignancies, or adverse drug reactions. Symptoms include severe and unexpected bleeding that may prove life-threatening.Case Study. We report a case of AHA associated with bullous pemphigoid (BP), a chronic, autoimmune, subepidermal, blistering skin disease. To our knowledge, this is the 25th documented case of such an association. Following treatment for less than 3 months consisting of methylprednisolone at decreasing dose levels along with four courses of rituximab (monoclonal antibody directed against the CD20 protein), AHA was completely cured and BP well-controlled.Conclusions. This report illustrates a rare association of AHA and BP, supporting the possibility of eradicating the inhibitor with a well-conducted short-term treatment.

scholarly journals The Kaposi’s Sarcoma-Associated Herpesvirus (KSHV) gH/gL Complex Is the Predominant Neutralizing Antigenic Determinant in KSHV-Infected Individuals

Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 256 ◽  
Author(s):  
Yasaman Mortazavi ◽  
Salum J. Lidenge ◽  
Tara Tran ◽  
John T. West ◽  
Charles Wood ◽  
...  
Keyword(s):  
Antigenic Determinant ◽  
Neutralizing Antibodies ◽  
Kaposi's Sarcoma ◽  
Kaposi’S Sarcoma ◽  
Sub Saharan Africa ◽  
People Living With Hiv ◽  
Viral Glycoproteins ◽  
Kaposi's Sarcoma Associated Herpesvirus ◽  
Sub Saharan ◽  
Kaposi’S Sarcoma Associated Herpesvirus

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi’s sarcoma (KS), one of the most prevalent cancers of people living with HIV/AIDS in sub-Saharan Africa. The seroprevalence for KSHV is high in the region, and no prophylactic vaccine against the virus is available. In this study, we characterized the antigenic targets of KSHV-specific neutralizing antibodies (nAbs) in asymptomatic KSHV-infected individuals and KS patients with high nAbs titers. We quantified the extent to which various KSHV envelope glycoproteins (gB, ORF28, ORF68, gH, gL, gM, gN and gpK8.1) adsorbed/removed KSHV-specific nAbs from the plasma of infected individuals. Our study revealed that plasma from a majority of KSHV neutralizers recognizes multiple viral glycoproteins. Moreover, the breadth of nAbs responses against these viral glycoproteins varies among endemic KS, epidemic KS and asymptomatic KSHV-infected individuals. Importantly, among the KSHV glycoproteins, the gH/gL complex, but neither gH nor gL alone, showed the highest adsorption of KSHV-specific nAbs. This activity was detected in 80% of the KSHV-infected individuals regardless of their KS status. The findings suggest that the gH/gL complex is the predominant antigenic determinant of KSHV-specific nAbs. Therefore, gH/gL is a potential target for development of KSHV prophylactic vaccines.

scholarly journals Progress in the rational design of an AIDS vaccine

2011 ◽  
Vol 366 (1579) ◽  
pp. 2759-2765 ◽  
Author(s):  
Gary J. Nabel ◽  
Peter D. Kwong ◽  
John R. Mascola
Keyword(s):  
Structural Biology ◽  
Neutralizing Antibodies ◽  
Rational Design ◽  
Computational Modelling ◽  
Effective Vaccine ◽  
Aids Vaccine ◽  
Immunodeficiency Virus ◽  
High Degree ◽  
Hiv 1 ◽  
Human Immunodeficiency Virus 1

Human immunodeficiency virus-1 (HIV-1) has a high degree of genetic and antigenic diversity that has impeded the development of an effective vaccine using traditional methods. We are attempting to develop an AIDS vaccine by employing strategies that include structural biology and computational modelling, in an effort to develop immunogens capable of eliciting neutralizing antibodies of the requisite breadth and potency against circulating strains of HIV-1.

Structurally Mapping Antigenic Epitopes of Adeno-Associated Virus 9: Development of Antibody Escape Variants

2021 ◽  
Author(s):  
Shanan N. Emmanuel ◽  
J. Kennon Smith ◽  
Jane Hsi ◽  
Yu-Shan Tseng ◽  
Matias Kaplan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Monoclonal Antibodies ◽  
Gene Delivery ◽  
General Population ◽  
Neutralizing Antibodies ◽  
Rational Design ◽  
Transduction Efficiency ◽  
Viral Neutralization ◽  
Patient Cohort ◽  
Antigenic Epitopes

Adeno-associated viruses (AAV) serve as vectors for therapeutic gene delivery. AAV9 vectors have been FDA approved, as Zolgensma®, for the treatment of spinal muscular atrophy and is being evaluated in clinical trials for the treatment of neurotropic and musculotropic diseases. A major hurdle for AAV-mediated gene delivery is the presence of pre-existing neutralizing antibodies in 40 to 80% of the general population. These pre-existing antibodies can reduce therapeutic efficacy through viral neutralization, and the size of the patient cohort eligible for treatment. In this study, cryo-electron microscopy and image reconstruction was used to define the epitopes of five anti-AAV9 monoclonal antibodies (MAbs); ADK9, HL2368, HL2370, HL2372, and HL2374, on the capsid surface. Three of these, ADK9, HL2370, and HL2374, bound on or near the icosahedral 3-fold axes, HL2368 to the 2/5-fold wall, and HL2372 to the region surrounding the 5-fold axes. Pseudo-atomic modeling enabled the mapping and identification of antibody contact amino acids on the capsid, including S454 and P659. These epitopes overlap with previously defined parvovirus antigenic sites. Capsid amino acids critical for the interactions were confirmed by mutagenesis followed by biochemical assays testing recombinant AAV9 (rAAV9) variants capable of escaping recognition and neutralization by the parental MAbs. These variants retained parental tropism and had similar or improved transduction efficiency compared to AAV9. These engineered rAAV9 variants could expand the patient cohort eligible for AAV9-mediated gene delivery by avoiding pre-existing circulating neutralizing antibodies. IMPORTANCE The use of recombinant AAVs (rAAVs) as delivery vectors for therapeutic genes is becoming increasingly popular, especially following the FDA approval of Luxturna® and Zolgensma®, based on serotypes AAV2 and AAV9, respectively. However, high titer anti-AAV neutralizing antibodies in the general population, exempts patients from treatment. The goal of this study is to circumvent this issue by creating AAV variant vectors not recognized by pre-existing neutralizing antibodies. The mapping of the antigenic epitopes of five different monoclonal antibodies (MAbs) on AAV9, to recapitulate a polyclonal response, enabled the rational design of escape variants with minimal disruption to cell tropism and gene expression. This study, which included four newly developed and now commercially available MAbs, provides a platform for the engineering of rAAV9 vectors that can be used to deliver genes to patients with pre-exiting AAV antibodies.

scholarly journals Effective screening of SARS-CoV-2 neutralizing antibodies in patient serum using lentivirus particles pseudotyped with SARS-CoV-2 spike glycoprotein

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ritesh Tandon ◽  
Dipanwita Mitra ◽  
Poonam Sharma ◽  
Martin G. McCandless ◽  
Stephen J. Stray ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Neutralizing Antibodies ◽  
Transduction Efficiency ◽  
Pseudotyped Virus ◽  
Spike Glycoprotein ◽  
Highly Pathogenic ◽  
Mammalian Cell Lines ◽  
Serological Studies ◽  
Pathogenic Viruses ◽  
Vesicular Stomatitis

Abstract Pseuodotyped particles have significant importance and use in virology as tools for studying the biology of highly pathogenic viruses in a lower biosafety environment. The biological, chemical, and serological studies of the recently emerged SARS-CoV-2 will be greatly aided by the development and optimization of a suitable pseudotyping system. Here, we pseudotyped the SARS-CoV-2 Spike glycoprotein (SPG) on a traditional retroviral (MMLV) as well as a third generation lentiviral (pLV) vector and tested the transduction efficiency in several mammalian cell lines expressing SARS-CoV-2 receptor hACE2. While MMLV pseudotyped the vesicular stomatitis virus G glycoprotein (VSV-G) efficiently, it could not pseudotype the full-length SPG. In contrast, pLV pseudotyped both glycoproteins efficiently; however, much higher titers of pLV-G particles were produced. Among all the tested mammalian cells, 293Ts expressing hACE2 were most efficiently transduced using the pLV-S system. The pLV-S particles were efficiently neutralized by diluted serum (>:640) from recently recovered COVID-19 patients who showed high SARS-CoV-2 specific IgM and IgG levels. In summary, pLV-S pseudotyped virus provides a valid screening tool for the presence of anti SARS-CoV-2 specific neutralizing antibodies in convalescent patient serum.

scholarly journals Rational Design of a Multipurpose Bioadhesive Vaginal Film for Co-Delivery of Dapivirine and Levonorgestrel

Pharmaceutics ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 1 ◽  
Author(s):  
Jing Li ◽  
Galit Regev ◽  
Sravan Kumar Patel ◽  
Dorothy Patton ◽  
Yvonne Sweeney ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Unintended Pregnancy ◽  
Rational Design ◽  
Sustained Drug Release ◽  
Single Entity ◽  
Female Reproductive Health ◽  
Vaginal Film ◽  
Life Threatening

Human immunodeficiency virus (HIV) infection and unintended pregnancy, which can lead to life-threatening complications, are two major burdens for female reproductive health. To address these pressing health issues, multipurpose prevention technologies (MPTs) are proposed to deliver two or more drugs simultaneously. MPTs could offer several benefits for users such as improved convenience, increased effectiveness, reduced cost, and decreased environmental burden. Here, we report the development, and in vitro and in vivo assessment of a bioadhesive vaginal film as a coitally-independent MPT dosage form for delivering dapivirine (DPV) and levonorgestrel (LNG) to prevent HIV infection and unintended pregnancy, respectively. After confirming the feasibility of bioadhesive film use for weekly drug delivery in vivo through colpophotography and MRI evaluation, the pharmacokinetics (PK) of DPV/LNG single entity and combination bioadhesive films was investigated in pigtailed macaques (n = 5). Both drugs from single entity or combination films were able to provide sustained drug release in vivo. The combination film showed lower local tissue clearance for DPV and exhibited significantly increased plasma concentration for LNG as compared to the single entity film. This proof-of-concept study demonstrates the ability of this novel bioadhesive film platform to deliver LNG and DPV simultaneously as an MPT product for the prevention of HIV infection and unintended pregnancy.

Elucidation of the Binding Regions of PAI-1 Neutralizing Antibodies Using Chimeric Variants of Human and Rat PAI-1

2001 ◽  
Vol 85 (05) ◽  
pp. 866-874 ◽  
Author(s):  
A. P. Bijnens ◽  
T. H. Ngo ◽  
A. Gils ◽  
J. Dewaele ◽  
I. Knockaert ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Plasminogen Activator ◽  
Neutralizing Antibodies ◽  
Rational Design ◽  
Biochemical Characterization ◽  
Tissue Type ◽  
Binding Region ◽  
Plasminogen Activator Inhibitor 1 ◽  
Inhibitory Antibodies ◽  
Pai 1

SummaryIncreased levels of plasminogen activator inhibitor-1 (PAI-1), the main physiological inhibitor of tissue-type plasminogen activator (t-PA) in plasma, are a known risk factor for thromboembolic and cardiovascular diseases. The elucidation of the binding site of inhibitory monoclonal antibodies may contribute to the rational design of PAI-1 modulating therapeutics. In this study, homolog-scanning mutagenesis was used to identify the binding region of a variety of human PAI-1 inhibitory antibodies, lacking cross-reactivity with rat PAI-1. Therefore, eight chimeric human/rat PAI-1 variants, containing rat PAI-1 substitutions at the N-terminal or C-terminal end with splicing sites at positions 26, 81, 187, 277 or 327, were generated and purified. Biochemical characterization revealed that all chimeras were folded properly. Subsequently, surface plasmon resonance was used to determine the affinity of various monoclonal antibodies for these chimera. Comparative analysis of the affinity and ELISA data allowed the identification of the major binding region of the inhibitory antibodies MA-8H9D4, MA-33B8F7, MA-44E4, MA-42A2F6 and MA-56A7C10. Thus, three segments in human PAI-1 containing each at least one site involved in the neutralization of PAI-1 activity could be identified, i.e. (1) the segment from residue 81 to residue 187 (comprising -helices hD, hE and hF, -strands s4C, s3A, s2A and s1A and the loops connecting these elements), (2) the segment between residues 277 and 327 (hI, thIs5A, s5A and s6A) and (3) the region C-terminal from amino acid 327, including the reactive site loop. The current data, together with previous data, indicate that PAI-1 contains at least four different regions that could be considered as putative targets to modulate its activity.

scholarly journals Single Amino Acid Substitutions in the Severe Acute Respiratory Syndrome Coronavirus Spike Glycoprotein Determine Viral Entry and Immunogenicity of a Major Neutralizing Domain

2005 ◽  
Vol 79 (18) ◽  
pp. 11638-11646 ◽  
Author(s):  
Christopher E. Yi ◽  
Lei Ba ◽  
Linqi Zhang ◽  
David D. Ho ◽  
Zhiwei Chen
Keyword(s):  
Amino Acid ◽  
Severe Acute Respiratory Syndrome ◽  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Rational Design ◽  
Antiviral Agents ◽  
Single Amino Acid ◽  
Major Mechanism ◽  
The Difference

ABSTRACT Neutralizing antibodies (NAbs) against severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) spike (S) glycoprotein confer protection to animals experimentally infected with the pathogenic virus. We and others previously demonstrated that a major mechanism for neutralizing SARS-CoV was through blocking the interaction between the S glycoprotein and the cellular receptor angiotensin-converting enzyme 2 (ACE2). In this study, we used in vivo electroporation DNA immunization and a pseudovirus-based assay to functionally evaluate immunogenicity and viral entry. We characterized the neutralization and viral entry determinants within the ACE2-binding domain of the S glycoprotein. The deletion of a positively charged region SΔ(422-463) abolished the capacity of the S glycoprotein to induce NAbs in mice vaccinated by in vivo DNA electroporation. Moreover, the SΔ(422-463) pseudovirus was unable to infect HEK293T-ACE2 cells. To determine the specific residues that contribute to related phenotypes, we replaced eight basic amino acids with alanine. We found that a single amino acid substitution (R441A) in the full-length S DNA vaccine failed to induce NAbs and abolished viral entry when pseudoviruses were generated. However, another substitution (R453A) abolished viral entry while retaining the capacity for inducing NAbs. The difference between R441A and R453A suggests that the determinants for immunogenicity and viral entry may not be identical. Our findings provide direct evidence that these basic residues are essential for immunogenicity of the major neutralizing domain and for viral entry. Our data have implications for the rational design of vaccine and antiviral agents as well as for understanding viral tropism.

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