scholarly journals Characterization of an In Vivo Neutralizing Anti-Vaccinia Virus D8 Single-Chain Fragment Variable (scFv) from a Human Anti-Vaccinia Virus-Specific Recombinant Library

Vaccines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1308
Author(s):  
Ulrike S. Diesterbeck ◽  
Henrike P. Ahsendorf ◽  
André Frenzel ◽  
Ahmad Reza Sharifi ◽  
Thomas Schirrmann ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Neutralizing Antibodies ◽  
Passive Immunization ◽  
Nmri Mouse ◽  
Single Chain ◽  
Single Chain Fragment Variable ◽  
Human Scfv ◽  
Human Immune Response

A panel of potent neutralizing antibodies are protective against orthopoxvirus (OPXV) infections. For the development of OPXV-specific recombinant human single-chain antibodies (scFvs), the IgG repertoire of four vaccinated donors was amplified from peripheral B-lymphocytes. The resulting library consisted of ≥4 × 108 independent colonies. The immuno-screening against vaccinia virus (VACV) Elstree revealed a predominant selection of scFv clones specifically binding to the D8 protein. The scFv-1.2.2.H9 was engineered into larger human scFv-Fc-1.2.2.H9 and IgG1-1.2.2.H9 formats to improve the binding affinity and to add effector functions within the human immune response. Similar binding kinetics were calculated for scFv-1.2.2.H9 and scFv-Fc-1.2.2.H9 (1.61 nM and 7.685 nM, respectively), whereas, for IgG1-1.2.2.H9, the Michaelis-Menten kinetics revealed an increased affinity of 43.8 pM. None of the purified recombinant 1.2.2.H9 formats were able to neutralize VACV Elstree in vitro. After addition of 1% human complement, the neutralization of ≥50% of VACV Elstree was achieved with 0.0776 µM scFv-Fc-1.2.2.H9 and 0.01324 µM IgG1-1.2.2.H9, respectively. In an in vivo passive immunization NMRI mouse model, 100 µg purified scFv-1.2.2.H9 and the IgG1-1.2.2.H9 partially protected against the challenge with 4 LD50 VACV Munich 1, as 3/6 mice survived. In contrast, in the scFv-Fc-1.2.2.H9 group, only one mouse survived the challenge.

scholarly journals Influenza prevention and treatment by passive immunization.

2014 ◽  
Vol 61 (3) ◽  
Author(s):  
Barbara Kalenik ◽  
Róża Sawicka ◽  
Anna Góra-Sochacka ◽  
Agnieszka Sirko
Keyword(s):  
Neutralizing Antibodies ◽  
Passive Immunization ◽  
Egg Yolk ◽  
Passive Immunity ◽  
Protective Effects ◽  
In Vivo Experiments ◽  
Effective Care ◽  
Antibody Preparations

Passive immunity is defined as a particular antigen resistance provided by external antibodies. It can be either naturally or artificially acquired. Natural passive immunization occurs during pregnancy and breast-feeding in mammals and during hatching in birds. Maternal antibodies are passed through the placenta and milk in mammals and through the egg yolk in birds. Artificial passive immunity is acquired by injection of either serum from immunized (or infected) individuals or antibody preparations. Many independent research groups worked on selection, verification and detailed characterization of polyclonal and monoclonal antibodies against the influenza virus. Numerous antibody preparations were tested in a variety of in vitro and in vivo experiments for their efficacy to neutralize the virus. Here, we describe types of antibodies tested in such experiments and their viral targets, review approaches resulting in identification of broadly neutralizing antibodies and discuss methods used to demonstrate their protective effects. Finally, we shortly discuss the phenomenon of maternal antibody transfer as a way of effective care for young individuals and as an interfering factor in early vaccination.

Novel antimalarial antibodies highlight the importance of the antibody Fc region in mediating protection

Blood ◽  
2003 ◽  
Vol 102 (13) ◽  
pp. 4424-4430 ◽  
Author(s):  
Richard J. Pleass ◽  
Solabomi A. Ogun ◽  
David H. McGuinness ◽  
Jan G. J. van de Winkel ◽  
Anthony A. Holder ◽  
...  
Keyword(s):  
Passive Immunization ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Plasmodium Yoelii ◽  
Single Chain ◽  
Parasite Drug Resistance ◽  
Parasite Challenge ◽  
Major Target

Abstract Parasite drug resistance and difficulties in developing effective vaccines have precipitated the search for alternative therapies for malaria. The success of passive immunization suggests that immunoglobulin (Ig)-based therapies are effective. To further explore the mechanism(s) by which antibody mediates its protective effect, we generated human chimeric IgG1 and IgA1 and a single-chain diabody specific for the C-terminal 19-kDa region of Plasmodium yoelii merozoite surface protein 1 (MSP119), a major target of protective immune responses. These novel human reagents triggered in vitro phagocytosis of merozoites but, unlike their parental mouse IgG2b, failed to protect against parasite challenge in vivo. Therefore, the Fc region appears critical for mediating protection in vivo, at least for this MSP119 epitope. Such antibodies may serve as prototype therapeutic agents, and as useful tools in the development of in vitro neutralization assays with Plasmodium parasites. (Blood. 2003;102:4424-4430)

scholarly journals New SHIVs and Improved Design Strategy for Modeling HIV-1 Transmission, Immunopathogenesis, Prevention and Cure

2021 ◽  
Author(s):  
Hui Li ◽  
Shuyi Wang ◽  
Fang-Hua Lee ◽  
Ryan S. Roark ◽  
Alex I. Murphy ◽  
...  
Keyword(s):  
T Cells ◽  
Neutralizing Antibodies ◽  
Large Scale ◽  
Rhesus Macaques ◽  
Passive Immunization ◽  
Design Strategy ◽  
Efficient Replication ◽  
Hiv 1

Previously, we showed that substitution of HIV-1 Env residue 375-Ser by bulky aromatic residues enhances binding to rhesus CD4 and enables primary HIV-1 Envs to support efficient replication as simian-human immunodeficiency virus (SHIV) chimeras in rhesus macaques (RMs). Here, we test this design strategy more broadly by constructing SHIVs containing ten primary Envs corresponding to HIV-1 subtypes A, B, C, AE and AG. All ten SHIVs bearing wildtype Env375 residues replicated efficiently in human CD4+ T cells, but only one replicated efficiently in primary rhesus cells. This was a subtype AE SHIV that naturally contained His at Env375. Replacement of wildtype Env375 residues by Trp, Tyr, Phe or His in the other nine SHIVs led to efficient replication in rhesus CD4+ T cells in vitro and in vivo. Nine SHIVs containing optimized Env375 alleles were grown large-scale in primary rhesus CD4+ T cells to serve as challenge stocks in preclinical prevention trials. These virus stocks were genetically homogeneous, native-like in Env antigenicity and tier-2 neutralization sensitivity, and transmissible by rectal, vaginal, penile, oral or intravenous routes. To facilitate future SHIV constructions, we engineered a simplified second-generation design scheme and validated it in RMs. Overall, our findings demonstrate that SHIVs bearing primary Envs with bulky aromatic substitutions at Env375 consistently replicate in RMs, recapitulating many features of HIV-1 infection in humans. Such SHIVs are efficiently transmitted by mucosal routes common to HIV-1 infection and can be used to test vaccine efficacy in preclinical monkey trials. Importance SHIV infection of Indian rhesus macaques is an important animal model for studying HIV-1 transmission, prevention, immunopathogenesis and cure. Such research is timely, given recent progress with active and passive immunization and novel approaches to HIV-1 cure. Given the multifaceted roles of HIV-1 Env in cell tropism and virus entry, and as a target for neutralizing and non-neutralizing antibodies, Envs selected for SHIV construction are of paramount importance. Until recently, it has been impossible to strategically design SHIVs bearing clinically relevant Envs that replicate consistently in monkeys. This changed with the discovery that bulky aromatic substitutions at residue Env375 confer enhanced affinity to rhesus CD4. Here, we show that 10 new SHIVs bearing primary HIV-1 Envs with residue 375 substitutions replicated efficiently in RMs and could be transmitted efficiently across rectal, vaginal, penile and oral mucosa. These findings suggest an expanded role for SHIVs as a model of HIV-1 infection.

scholarly journals Recombinant dimeric small immunoproteins neutralize transmissible gastroenteritis virus infectivity efficiently in vitro and confer passive immunity in vivo

2007 ◽  
Vol 88 (1) ◽  
pp. 187-195 ◽  
Author(s):  
Marco Bestagno ◽  
Isabel Sola ◽  
Eliana Dallegno ◽  
Patricia Sabella ◽  
Monica Poggianella ◽  
...  
Keyword(s):  
Passive Immunization ◽  
Transmissible Gastroenteritis Virus ◽  
Virus Infectivity ◽  
Single Chain ◽  
Variable Regions ◽  
Chain Molecules ◽  
Gastroenteritis Virus ◽  
Transmissible Gastroenteritis

Small immunoproteins (SIPs) are single-chain molecules comprising the variable regions of an antibody assembled in a single polypeptide (scFv) and joined to the immunoglobulin heavy-chain dimerizing domain. To investigate the potential of these molecules to provide protection against enteric infections when supplied orally, SIPs were generated against Transmissible gastroenteritis virus (TGEV), a highly pathogenic porcine virus. Different variants of TGEV-specific SIPs were created, of ε and α isotypes, by exploiting the dimerizing domains εCH4 and αCH3 of human and swine origin. Transfected cells secreted these recombinant mini-antibodies efficiently, mainly as dimers stabilized covalently by inter-chain disulphide bridges. The specificity and functionality of the recombinant TGEV-specific SIPs were determined by in vitro binding, neutralization and infection-interference assays. The neutralization indices of the TGEV-specific SIPs were all very similar to that of the original TGEV-specific mAb, thus confirming that the immunological properties have been preserved in the recombinant SIPs. In vivo protection experiments on newborn piglets have, in addition, demonstrated a strong reduction of virus titre in infected tissues of animals treated orally with TGEV-specific SIPs. It has therefore been demonstrated that it is possible to confer passive immunization to newborn pigs by feeding them with recombinant SIPs.

scholarly journals Human neutralizing antibodies for SARS-CoV-2 prevention and immunotherapy

2021 ◽  
Author(s):  
Dongyan Zhou ◽  
Runhong Zhou ◽  
Zhiwei Chen
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Neutralizing Antibodies ◽  
Immune Escape ◽  
Passive Immunization ◽  
Clinical Development ◽  
Vaccine Research ◽  
Breakthrough Infection ◽  
Clinical Benefits

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). SARS-CoV-2 has been spreading worldwide since December 2019, resulting in the ongoing COVID-19 pandemic with 237 million infections and 4.8 million deaths by 11 October 2021. While there are great efforts of global vaccination, ending this pandemic has been challenged by issues of exceptionally high viral transmissibility, re-infection, vaccine-breakthrough infection, and immune escape variants of concerns. Besides the record-breaking speed of vaccine research and development, antiviral drugs including SARS-CoV-2-specific human neutralizing antibodies (HuNAbs) have been actively explored for passive immunization. In support of HuNAb-based immunotherapy, passive immunization using convalescent patients’ plasma have generated promising evidence on clinical benefits for both mild and severe COVID-19 patients. Since the source of convalescent plasma is limited, the discovery of broadly reactive HuNAbs may have significant impacts on the fight against the COVID-19 pandemic. In this review, therefore, we discuss the current technologies of gene cloning, modes of action, in vitro and in vivo potency and breadth, and clinical development for potent SARS-CoV-2-specific HuNAbs.

scholarly journals In Vivo and In Vitro Escape from Neutralizing Antibodies 2G12, 2F5, and 4E10

2007 ◽  
Vol 81 (16) ◽  
pp. 8793-8808 ◽  
Author(s):  
Amapola Manrique ◽  
Peter Rusert ◽  
Beda Joos ◽  
Marek Fischer ◽  
Herbert Kuster ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
In Vitro Selection ◽  
Passive Immunization ◽  
Resistance Mutations ◽  
Antibody Treatment ◽  
Glycosylation Sites ◽  
Depth Analysis ◽  
Immunodeficiency Virus

ABSTRACT Recently, passive immunization of human immunodeficiency virus (HIV)-infected individuals with monoclonal antibodies (MAbs) 2G12, 2F5, and 4E10 provided evidence of the in vivo activity of 2G12 but raised concerns about the function of the two membrane-proximal external region (MPER)-specific MAbs (A. Trkola, H. Kuster, P. Rusert, B. Joos, M. Fischer, C. Leemann, A. Manrique, M. Huber, M. Rehr, A. Oxenius, R. Weber, G. Stiegler, B. Vcelar, H. Katinger, L. Aceto, and H. F. Gunthard, Nat. Med. 11:615-622, 2005). In the light of MPER-targeting vaccines under development, we performed an in-depth analysis of the emergence of mutations conferring resistance to these three MAbs to further elucidate their activity. Clonal analysis of the MPER of plasma virus samples derived during antibody treatment confirmed that no changes in this region had occurred in vivo. Sequence analysis of the 2G12 epitope relevant N-glycosylation sites of viruses derived from 13 patients during the trial supported the phenotypic evaluation, demonstrating that mutations in these sites are associated with resistance. In vitro selection experiments with isolates of four of these individuals corroborated the in vivo finding that virus strains rapidly escape 2G12 pressure. Notably, in vitro resistance mutations differed, in most cases, from those found in vivo. Importantly, in vitro selection with 2F5 and 4E10 demonstrated that resistance to these MAbs can be difficult to achieve and can lead to selection of variants with impaired infectivity. This remarkable vulnerability of the virus to interference within the MPER calls for a further evaluation of the safety and efficacy of MPER-targeting therapeutic and vaccination strategies.

scholarly journals Immunotoxins Containing Recombinant Anti-CTLA-4 Single-Chain Fragment Variable Antibodies and Saporin: In Vitro Results and In Vivo Effects in an Acute Rejection Model

2001 ◽  
Vol 167 (8) ◽  
pp. 4222-4229 ◽  
Author(s):  
Pier-Luigi Tazzari ◽  
Letizia Polito ◽  
Andrea Bolognesi ◽  
Maria-Pia Pistillo ◽  
Paolo Capanni ◽  
...  
Keyword(s):  
Acute Rejection ◽  
Single Chain ◽  
Chain Fragment ◽  
Single Chain Fragment Variable ◽  
In Vivo Effects ◽  
Single Chain Fragment

scholarly journals Single dose of a replication-defective vaccinia virus expressing Zika virus-like particles is protective in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brittany Jasperse ◽  
Caitlin M. O’Connell ◽  
Yuxiang Wang ◽  
Paulo H. Verardi
Keyword(s):  
Single Dose ◽  
Vaccinia Virus ◽  
Zika Virus ◽  
Neutralizing Antibodies ◽  
Novel Mutation ◽  
Booster Vaccination ◽  
Vaccine Candidates ◽  
Virus Like Particles

AbstractZika virus (ZIKV), a flavivirus transmitted primarily by infected mosquitos, can cause neurological symptoms such as Guillian–Barré syndrome and microcephaly. We developed several vaccinia virus (VACV) vaccine candidates for ZIKV based on replication-inducible VACVs (vINDs) expressing ZIKV pre-membrane (prM) and envelope (E) proteins (vIND-ZIKVs). These vIND-ZIKVs contain elements of the tetracycline operon and replicate only in the presence of tetracyclines. The pool of vaccine candidates was narrowed to one vIND-ZIKV containing a novel mutation in the signal peptide of prM that led to higher expression and secretion of E and production of virus-like particles, which was then tested for safety, immunogenicity, and efficacy in mice. vIND-ZIKV grows to high titers in vitro in the presence of doxycycline (DOX) but is replication-defective in vivo in the absence of DOX, causing no weight loss in mice. C57BL/6 mice vaccinated once with vIND-ZIKV in the absence of DOX (as a replication-defective virus) developed robust levels of E-peptide-specific IFN-γ-secreting splenocytes and anti-E IgG titers, with modest levels of serum-neutralizing antibodies. Vaccinated mice treated with anti-IFNAR1 antibody were completely protected from ZIKV viremia post-challenge after a single dose of vIND-ZIKV. Furthermore, mice with prior immunity to VACV developed moderate anti-E IgG titers that increased after booster vaccination, and were protected from viremia only after two vaccinations with vIND-ZIKV.

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