Qualitative and Quantitative Variables that Affect the Potency of Fc- Mediated Effector Function In Vitro and In Vivo: Considerations for Passive Immunization Using Non-Neutralizing Antibodies

2013 ◽  
Vol 11 (5) ◽  
pp. 354-364 ◽  
Author(s):  
George Lewis
Keyword(s):  
Neutralizing Antibodies ◽  
Passive Immunization ◽  
Effector Function ◽  
Qualitative And Quantitative

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.

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 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 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 Blocking the GITR-GITRL pathway to overcome resistance to therapy in sarcomatoid malignant pleural mesothelioma

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Meilin Chan ◽  
Licun Wu ◽  
Zhihong Yun ◽  
Trevor D. McKee ◽  
Michael Cabanero ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Malignant Pleural Mesothelioma ◽  
Neutralizing Antibodies ◽  
Pleural Mesothelioma ◽  
Spheroid Formation ◽  
Resistance To Therapy ◽  
Sarcomatoid Mesothelioma

AbstractMalignant pleural mesothelioma (MPM) is an aggressive neoplasm originating from the pleura. Non-epithelioid (biphasic and sarcomatoid) MPM are particularly resistant to therapy. We investigated the role of the GITR-GITRL pathway in mediating the resistance to therapy. We found that GITR and GITRL expressions were higher in the sarcomatoid cell line (CRL5946) than in non-sarcomatoid cell lines (CRL5915 and CRL5820), and that cisplatin and Cs-137 irradiation increased GITR and GITRL expressions on tumor cells. Transcriptome analysis demonstrated that the GITR-GITRL pathway was promoting tumor growth and inhibiting cell apoptosis. Furthermore, GITR+ and GITRL+ cells demonstrated increased spheroid formation in vitro and in vivo. Using patient derived xenografts (PDXs), we demonstrated that anti-GITR neutralizing antibodies attenuated tumor growth in sarcomatoid PDX mice. Tumor immunostaining demonstrated higher levels of GITR and GITRL expressions in non-epithelioid compared to epithelioid tumors. Among 73 patients uniformly treated with accelerated radiation therapy followed by surgery, the intensity of GITR expression after radiation negatively correlated with survival in non-epithelioid MPM patients. In conclusion, the GITR-GITRL pathway is an important mechanism of autocrine proliferation in sarcomatoid mesothelioma, associated with tumor stemness and resistance to therapy. Blocking the GITR-GITRL pathway could be a new therapeutic target for non-epithelioid mesothelioma.

scholarly journals Effects of Size and Surface Properties of Nanodiamonds on the Immunogenicity of Plant-Based H5 Protein of A/H5N1 Virus in Mice

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1597
Author(s):  
Thuong Thi Ho ◽  
Van Thi Pham ◽  
Tra Thi Nguyen ◽  
Vy Thai Trinh ◽  
Tram Vi ◽  
...  
Keyword(s):  
High Pressure ◽  
Neutralizing Antibodies ◽  
H5n1 Virus ◽  
Vaccine Development ◽  
Particle Characterization ◽  
Innovative Strategy ◽  
Specific Igg ◽  
Positively Charged

Nanodiamond (ND) has recently emerged as a potential nanomaterial for nanovaccine development. Here, a plant-based haemagglutinin protein (H5.c2) of A/H5N1 virus was conjugated with detonation NDs (DND) of 3.7 nm in diameter (ND4), and high-pressure and high-temperature (HPHT) oxidative NDs of ~40–70 nm (ND40) and ~100–250 nm (ND100) in diameter. Our results revealed that the surface charge, but not the size of NDs, is crucial to the protein conjugation, as well as the in vitro and in vivo behaviors of H5.c2:ND conjugates. Positively charged ND4 does not effectively form stable conjugates with H5.c2, and has no impact on the immunogenicity of the protein both in vitro and in vivo. In contrast, the negatively oxidized NDs (ND40 and ND100) are excellent protein antigen carriers. When compared to free H5.c2, H5.c2:ND40, and H5.c2:ND100 conjugates are highly immunogenic with hemagglutination titers that are both 16 times higher than that of the free H5.c2 protein. Notably, H5.c2:ND40 and H5.c2:ND100 conjugates induce over 3-folds stronger production of both H5.c2-specific-IgG and neutralizing antibodies against A/H5N1 than free H5.c2 in mice. These findings support the innovative strategy of using negatively oxidized ND particles as novel antigen carriers for vaccine development, while also highlighting the importance of particle characterization before use.

scholarly journals Optimized Adenovirus-Antibody Complexes Stimulate Strong Cellular and Humoral Immune Responses against an Encoded Antigen in Naïve Mice and Those with Preexisting Immunity

2011 ◽  
Vol 19 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Jin Huk Choi ◽  
Joe Dekker ◽  
Stephen C. Schafer ◽  
Jobby John ◽  
Craig E. Whitfill ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
T Cell Responses ◽  
Transduction Efficiency ◽  
Virus Antibody ◽  
Cell Responses

ABSTRACTThe immune response to recombinant adenoviruses is the most significant impediment to their clinical use for immunization. We test the hypothesis that specific virus-antibody combinations dictate the type of immune response generated against the adenovirus and its transgene cassette under certain physiological conditions while minimizing vector-induced toxicity.In vitroandin vivoassays were used to characterize the transduction efficiency, the T and B cell responses to the encoded transgene, and the toxicity of 1 × 1011adenovirus particles mixed with different concentrations of neutralizing antibodies. Complexes formed at concentrations of 500 to 0.05 times the 50% neutralizing dose (ND50) elicited strong virus- and transgene-specific T cell responses. The 0.05-ND50formulation elicited measurable anti-transgene antibodies that were similar to those of virus alone (P= 0.07). This preparation also elicited very strong transgene-specific memory T cell responses (28.6 ± 5.2% proliferation versus 7.7 ± 1.4% for virus alone). Preexisting immunity significantly reduced all responses elicited by these formulations. Although lower concentrations (0.005 and 0.0005 ND50) of antibody did not improve cellular and humoral responses in naïve animals, they did promote strong cellular (0.005 ND50) and humoral (0.0005 ND50) responses in mice with preexisting immunity. Some virus-antibody complexes may improve the potency of adenovirus-based vaccines in naïve individuals, while others can sway the immune response in those with preexisting immunity. Additional studies with these and other virus-antibody ratios may be useful to predict and model the type of immune responses generated against a transgene in those with different levels of exposure to adenovirus.

scholarly journals A broadly neutralizing monoclonal antibody induces broad protection against heterogeneous PRRSV strains in piglets

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Zhigang Zhang ◽  
Tianshu Zhai ◽  
Mingshuo Li ◽  
Kun Zhang ◽  
Jingrui Li ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Neutralizing Antibodies ◽  
Antigenic Variation ◽  
Profile Analysis ◽  
Expression Profiles ◽  
Enrichment Analysis ◽  
Antibody Isotype ◽  
Hilar Lymph Node

AbstractNeutralizing antibodies (NAbs) have attracted attention as tools for achieving PRRSV control and prevention, but viral antigenic variation undermines the abilities of NAbs elicited by attenuated PRRSV vaccines to confer full protection against heterogeneous PRRSV field isolates. As demonstrated in this study, the monoclonal antibody (mAb) mAb-PN9cx3 exhibited broad-spectrum recognition and neutralizing activities against PRRSV-1 and PRRSV-2 strains in vitro. Furthermore, in vivo experiments revealed that the administration of two 10-mg doses of mAb-PN9cx3 before and after the inoculation of piglets with heterologous PRRSV isolates (HP-PRRSV-JXA1 or PRRSV NADC30-like strain HNhx) resulted in significant reduction of the PRRSV-induced pulmonary pathological changes and virus loads in porcine alveolar macrophages (PAMs) compared with the results obtained with mAb-treated isotype controls. Moreover, minimal hilar lymph node PRRSV antigen levels were observed in mAb-PN9cx3-treated piglets. A transcriptome profile analysis of PAMs extracted from lung tissues of piglets belonging to different groups (except for antibody-isotype controls) indicated that mAb-PN9cx3 treatment reversed the PRRSV infection-induced alterations in expression profiles. A gene ontology (GO) enrichment analysis of these genes traced their functions to pathways that included the immune response, inflammatory response, and response to steroid hormone, and their functions in oogenesis and positive regulation of angiogenesis have been implicated in PRRSV pathogenesis. Overall, NADC30-like HNhx infection affected more gene pathways than HP-PRRSV infection. In conclusion, our research describes a novel immunologic approach involving the use of mAbs that confer cross-protection against serious illness resulting from infection with heterogeneous PRRSV-2 isolates, which is a feat that has not yet been achieved through vaccination. Ultimately, mAb-PN9cx3 will be a powerful addition to our current arsenal for achieving PRRSV prevention and eradication.

scholarly journals POS0042 NOTCH 1 INHIBITION INCREASES OSTEOCLAST PROGENITOR ACTIVITY IN THE MOUSE MODEL OF RHEUMATOID ARTHRITIS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 226.3-226
Author(s):  
M. Filipović ◽  
A. Šućur ◽  
D. Flegar ◽  
Z. Jajić ◽  
M. Ikić Matijašević ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Notch Signaling ◽  
Neutralizing Antibodies ◽  
Osteoclast Differentiation ◽  
Notch Receptor ◽  
Notch 1 ◽  
Collagen Induced Arthritis ◽  
Notch Receptors

Background:Osteoclasts mediate periarticular and systemic bone loss in rheumatoid arthritis (RA). Osteoclast progenitor cells (OCPs) derived from the myeloid lineage are susceptible to regulation through Notch signaling. Murine bone marrow and splenic OCPs, identified as CD45+Ly6G-CD3-B220-NK1.1-CD11blo/+CD115+CCR2+ cells, are specifically increased in arthritis. We previously identified an increased frequency of OCPs expressing Notch receptors in arthritic mice.Objectives:Several studies suggested that Notch signaling modulation affects the course of experimental arthritis. We aimed to determine the effects of Notch receptor signaling inhibition on OCP activity and arthritis severity in murine collagen-induced arthritis (CIA).Methods:Male C57/Bl6 and DBA mice were immunized with chicken type II collagen and treated with i.p. injections of anti-Notch 1 neutralizing antibodies (1mg/kg). Notch receptor 1 through 4 expression on OCPs was analyzed by flow cytometry in periarticular bone marrow (PBM) and spleen (SPL). Gene expression of Notch receptors, ligands and transcription targets as well as osteoclast differentiation genes RANK, cFos and cFms was determined by qPCR from tissues and sorted OCPs. FACS sorted OCPs were stimulated by osteoclastogenic factors (M-CSF and RANKL), in control, IgG, Jagged (Jag)1 or Delta-like (DLL)1 coated wells, with or without anti-Notch 1 antibodies. Research was approved by the Ethics Committee.Results:We confirmed the expression of Notch receptors on OCPs by flow cytometry with Notch 1 and 2 being most abundantly expressed (around 25% and 40% positive OCPs in PBM and 35% and 20% in SPL respectively), with a significant increase of Notch 2 expression in arthritis. Seeding OCPs on DLL1 coated wells significantly increased while seeding on Jag1 coated wells significantly decreased osteoclastogenesis as reflected on the number of TRAP+ osteoclasts and expression of osteoclast differentiation genes. The addition of anti-Notch 1 antibodies to ligand-stimulated OCPs resulted in an increased number of TRAP+ osteoclasts, partially reversing Jag1 inhibition. In vivo treatment with anti-Notch 1 antibodies did not affect total OCP frequency, but increased expression of Notch 4 both in PBM and SPL as seen by flow cytometry and qPCR. Additionally, anti-Notch 1 treatment stimulated Notch transcription factors HES and HEY. Both PBM and SPL cultured OCPs from anti-Notch 1 treated mice produced a higher number of large TRAP+ osteoclasts, doubling the area covered with osteoclasts in the latter compared to untreated mice. Increased osteoclastogenesis in vitro was further confirmed by an increased expression of osteoclast differentiation genes in the treated group.Conclusion:Our results confirm that Notch signaling may represent an important therapeutic target for the regulation of osteoclast activity in arthritis. Both in vitro and in vivo anti-Notch 1 neutralizing antibodies enhanced osteoclastogenesis in CIA model, implying an inhibitory role of Notch 1 signaling in osteoclast differentiation. As Notch 2 expression is increased on OCPs of arthritic mice, we next plan to determine the effects of Notch 2 neutralization on osteoclast activity and arthritis severity.References:[1]Ikić Matijašević M, Flegar D, Kovačić N, Katavić V, Kelava T, Šućur A, et al. Increased chemotaxis and activity of circulatory myeloid progenitor cells may contribute to enhanced osteoclastogenesis and bone loss in the C57BL/6 mouse model of collagen-induced arthritis. Clin Exp Immunol. 2016;186(3):321–35.[2]Šućur A, Filipović M, Flegar D, Kelava T, Šisl D, Lukač N, et al. Notch receptors and ligands in inflammatory arthritis – a systematic review. Immunology Letters 2020 Vol. 223, p. 106–14.Acknowledgements:The work has been supported by Croatian Science Foundation projects IP-2018-01-2414, UIP-2017-05-1965 and DOK-2018-09-4276.Disclosure of Interests:None declared.

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