scholarly journals Post-exposure protection of SARS-CoV-2 lethal infected K18-hACE2 transgenic mice by neutralizing human monoclonal antibody

2020 ◽  
Author(s):  
Ronit Rosenfeld ◽  
Tal Noy-Porat ◽  
Adva Mechaly ◽  
Efi Makdasi ◽  
Yinon Levy ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Transgenic Mice ◽  
Neutralizing Antibodies ◽  
Global Economy ◽  
Human Monoclonal Antibody ◽  
Human Monoclonal Antibodies ◽  
Mortality And Morbidity ◽  
Life Saving ◽  
Therapeutic Value

AbstractCoronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), exhibits high levels of mortality and morbidity and has dramatic consequences on human live, sociality and global economy. Neutralizing antibodies constitute a highly promising approach for treating and preventing infection by this novel pathogen. In the present study, we characterized and further evaluated the recently identified human monoclonal MD65 antibody for its ability to provide protection against a lethal SARS-CoV-2 infection of K18-hACE2 transgenic mice. 75% of the untreated mice succumbed 6-9 days post-infection while administration of the MD65 antibody as late as 3 days after exposure, rescued all infected animals. The data unprecedentedly demonstrate, the therapeutic value of human monoclonal antibodies as a life-saving treatment of severe COVID-19 infection.

scholarly journals Post-exposure protection of SARS-CoV-2 lethal infected K18-hACE2 transgenic mice by neutralizing human monoclonal antibody

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ronit Rosenfeld ◽  
Tal Noy-Porat ◽  
Adva Mechaly ◽  
Efi Makdasi ◽  
Yinon Levy ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Transgenic Mice ◽  
Neutralizing Antibodies ◽  
Global Economy ◽  
Human Life ◽  
Human Monoclonal Antibody ◽  
Human Monoclonal Antibodies ◽  
Mortality And Morbidity ◽  
Life Saving ◽  
Therapeutic Value

AbstractThe coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), exhibits high levels of mortality and morbidity and has dramatic consequences on human life, sociality and global economy. Neutralizing antibodies constitute a highly promising approach for treating and preventing infection by this novel pathogen. In the present study, we characterize and further evaluate the recently identified human monoclonal MD65 antibody for its ability to provide protection against a lethal SARS-CoV-2 infection of K18-hACE2 transgenic mice. Eighty percent of the untreated mice succumbed 6–9 days post-infection, while administration of the MD65 antibody as late as 3 days after exposure rescued all infected animals. In addition, the efficiency of the treatment is supported by prevention of morbidity and ablation of the load of infective virions in the lungs of treated animals. The data demonstrate the therapeutic value of human monoclonal antibodies as a life-saving treatment for severe COVID-19 infection.

scholarly journals Maternally Derived Recombinant Human Anti-Hantavirus Monoclonal Antibodies Are Transferred to Mouse Offspring during Lactation and Neutralize Virus In Vitro

2006 ◽  
Vol 80 (8) ◽  
pp. 4183-4186 ◽  
Author(s):  
Shuyang Yu ◽  
Mifang Liang ◽  
BaoLiang Fan ◽  
Hongtao Xu ◽  
Chuan Li ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Transgenic Mice ◽  
Light Chain ◽  
Human Monoclonal Antibody

ABSTRACT Transgenic mice expressing a recombinant human monoclonal antibody (rHMAb) against hantavirus were generated. These mice could be used as models to explore the possibilities of producing rHMAbs for therapeutic purposes. The highest concentration of the rHMAb in the milk of the transgenic females was 6.6 mg/ml. The rHMAb was also detected in the sera of pups fed by the transgenic females. Both the rHMAbs in the milk of transgenic mice and those in the sera of suckling pups were found to be active against hantaviruses, although the light chain of the antibody absorbed by the pups was modified by N-linked glycosylation.

Abstract 14697: Novel Assays for Quantification of Lipoprotein-Associated (PCSK9-apoB, PCSK9-Lp(a)) Proprotein Covertase Subtilisin/Kexin Type 9 (PCKS9)

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Calvin Yeang ◽  
Yun-Seok Choi ◽  
Sang-Rok Lee ◽  
Monica L Bertoia ◽  
Eric B Rimm ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Human Plasma ◽  
Polyclonal Antibodies ◽  
Human Monoclonal Antibody ◽  
Ldl Receptor ◽  
Plasma Lipoproteins ◽  
Health Study ◽  
Clinical Samples ◽  
Ldl Particles

Background: PCSK9 is a major regulator of plasma LDL-C. Monoclonal antibodies to PCSK9 lower LDL-C by 45-65% and Lp(a) by 9-38%. The canonical function of PCSK9 is binding of LDL-receptor (LDLR) via its extracellular EGF-A domain, and subsequently mediating LDLR degradation. However, PCSK9 also weakly associates with plasma lipoproteins, with 20-40% of total plasma PCSK9 found on LDL. However, most LDL particles do not contain PCSK9. Whether PCSK9 also associates with other lipoproteins such as Lp(a) are not well described. Methods: Sensitive and quantitative sandwich-based ELISA assays were developed to measure PCSK9 associated plasma lipoproteins in both mouse and human plasma. For human plasma, commercial rabbit polyclonal antibodies binding to the C-terminal region of PCSK9 (Abgent, ThermoFisher) or REGN727 human monoclonal antibody were bound to microtiter well plates. Plasma was added and monoclonal antibodies MB47 and LPA4, binding to apoB-100 and apo(a) respectively, were used to detect PCSK9-apoB-100 and PCSK9-Lp(a) complexes with a chemiluminescent ELISA. For mouse assays, REGN727 was used as the capture antibody as it detects mouse PCSK9 and monoclonal antibody LF3 was used to detect mouse apoB. Results: PCSK9-apoB and PCSK9-Lp(a) complexes could be detected in both human plasma and in various mouse models expressing apo(a) or Lp(a). The signal to noise ratio was ~20 fold in various clinical samples, including in healthy subjects and in patients with cardiovascular disease. In 536 clinical samples from the Health Professional Follow-Up Study, PCSK9-Lp(a) correlated strongly with Lp(a) (r=0.59, p<0.001, age-adjusted) but not other lipid variables. PCSK9-apoB correlated weakly with PCSK9-Lp(a) (r=0.30, p<0.001, age-adjusted) and LDL-C (r=0.22, p<0.001, age-adjusted). These associations were virtually the same in 526 women in the Nurses’ Health Study. Conclusions: Novel ELISAs were generated to quantitate lipoprotein-associated PCSK9 in transgenic mouse and human plasma, including on apoB and Lp(a). Changes in PCSK9-Lp(a) complexes may provide insights into the Lp(a)-lowering effect of PCSK9 antibodies. Whether these assays will predict CVD outcomes waits to be determined in PCSK9 antibody and epidemiological studies.

Generation of Human Monoclonal Anti-idiotypic Antibodies with Specificity to the Murine Monoclonal Anti-CA 125 Antibody B43.13

1996 ◽  
Vol 11 (4) ◽  
pp. 211-215
Author(s):  
J.B. Oltrogge ◽  
B. Donnerstag ◽  
R.P. Baum ◽  
A.A. Noujaim ◽  
L. Träger
Keyword(s):  
Ovarian Cancer ◽  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Peripheral Blood Lymphocytes ◽  
Cross Reactivity ◽  
Tumor Burden ◽  
Ca 125 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Monoclonal Antibodies ◽  
Ebv Transformation

Two human monoclonal antibodies, HID-7E7 and ROB-6F2, were produced by EBV transformation of peripheral blood lymphocytes (PBL). PBL were obtained from a patient with ovarian cancer who had been exposed several times to a Tc-99m labeled murine monoclonal anti-CA 125 antibody (B43.13, Biomira, Edmonton) for immunoscintigraphy. The HID-7E7 and ROB-6F2 producing B-cells were cloned with a limiting dilution technique and have shown stable immunoglobulin secretion within a period of three years. The human monoclonal antibodies HID-7E7 and ROB-6F2 are of the IgG isotype, and bind with significant affinity to the murine monoclonal antibody B43.13, which was used for immunoscintigraphy. Binding affinity of ROB-6F2 to other murine antibodies could not be detected. Cross reactivity of HID-7E7 to a murine anti-CEA monoclonal antibody was observed. In order to verify the anti-idiotypic character of the generated human antibodies, the ability of HID-7E7 and ROB-6F2, respectively, to inhibit the formation of the CA125/B43.13 complex is demonstrated via an enzyme-linked immunosorbent assay. These human anti-idiotypic antibodies are possible candidates for immunotherapy of ovarian cancer in patients with a small tumor burden following surgery and/or chemotherapy.

scholarly journals Isolation of a human monoclonal antibody specific for the receptor binding domain of SARS-CoV-2 using a competitive phage biopanning strategy

2020 ◽  
Vol 3 (2) ◽  
pp. 95-100 ◽  
Author(s):  
Xin Zeng ◽  
Lingfang Li ◽  
Jing Lin ◽  
Xinlei Li ◽  
Bin Liu ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Magnetic Beads ◽  
Human Monoclonal Antibody ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Antibody Library ◽  
Synthetic Antibody ◽  
Blocking Antibodies

Abstract The infection of the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused more than 200 000 deaths, but no vaccine or therapeutic monoclonal antibody is currently available. SARS-CoV-2 relies on its spike protein, in particular the receptor-binding domain (RBD), to bind human cell receptor angiotensin-converting enzyme 2 (ACE2) for viral entry, and thus targeting RBD holds the promise for preventing SARS-CoV-2 infection. In this work, a competitive biopanning strategy of a phage display antibody library was applied to screen blocking antibodies against RBD. High-affinity antibodies were enriched after the first round using a standard panning process in which RBD-His was immobilized as a bait. At the next two rounds, immobilized ACE2-Fc and free RBD-His were mixed with the enriched phage antibodies. Antibodies binding to RBD at epitopes different from ACE2-binding site were captured by the immobilized ACE2-Fc, forming a “sandwich” complex. Only antibodies competed with ACE2 can bind to the free RBD-His in the supernatant and be subsequently separated by the nickel-nitrilotriacetic acid magnetic beads. rRBD-15 from the competitive biopanning of our synthetic antibody library, Lib AB1, was produced as the full-length IgG1 format. It was proved to competitively block the binding of RBD to ACE2 and potently inhibit SARS-CoV-2 pseudovirus infection with IC50 values of 12 nM. Nevertheless, rRBD-16 from the standard biopanning can only bind to RBD in vitro, but not have the blocking or neutralization activity. Our strategy can efficiently isolate the blocking antibodies of RBD, and it would speed up the discovery of neutralizing antibodies against SARS-CoV-2.

scholarly journals Dengue Virus Envelope Dimer Epitope Monoclonal Antibodies Isolated from Dengue Patients Are Protective against Zika Virus

mBio ◽  
2016 ◽  
Vol 7 (4) ◽  
Author(s):  
J. A. Swanstrom ◽  
J. A. Plante ◽  
K. S. Plante ◽  
E. F. Young ◽  
E. McGowan ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Dengue Virus ◽  
Pregnant Women ◽  
Zika Virus ◽  
Neutralizing Antibodies ◽  
Severe Disease ◽  
Fetal Loss ◽  
Human Monoclonal Antibodies ◽  
Serum Dilution ◽  
Homologous Virus

ABSTRACT Zika virus (ZIKV) is a mosquito-borne flavivirus responsible for thousands of cases of severe fetal malformations and neurological disease since its introduction to Brazil in 2013. Antibodies to flaviviruses can be protective, resulting in lifelong immunity to reinfection by homologous virus. However, cross-reactive antibodies can complicate flavivirus diagnostics and promote more severe disease, as noted after serial dengue virus (DENV) infections. The endemic circulation of DENV in South America and elsewhere raises concerns that preexisting flavivirus immunity may modulate ZIKV disease and transmission potential. Here, we report on the ability of human monoclonal antibodies and immune sera derived from dengue patients to neutralize contemporary epidemic ZIKV strains. We demonstrate that a class of human monoclonal antibodies isolated from DENV patients neutralizes ZIKV in cell culture and is protective in a lethal murine model. We also tested a large panel of convalescent-phase immune sera from humans exposed to primary and repeat DENV infection. Although ZIKV is most closely related to DENV compared to other human-pathogenic flaviviruses, most DENV immune sera (73%) failed to neutralize ZIKV, while others had low (50% effective concentration [EC 50 ], <1:100 serum dilution; 18%) or moderate to high (EC 50 , >1:100 serum dilution; 9%) levels of cross-neutralizing antibodies. Our results establish that ZIKV and DENV share epitopes that are targeted by neutralizing, protective human antibodies. The availability of potently neutralizing human monoclonal antibodies provides an immunotherapeutic approach to control life-threatening ZIKV infection and also points to the possibility of repurposing DENV vaccines to induce cross-protective immunity to ZIKV. IMPORTANCE ZIKV is an emerging arbovirus that has been associated with severe neurological birth defects and fetal loss in pregnant women and Guillain-Barré syndrome in adults. Currently, there is no vaccine or therapeutic for ZIKV. The identification of a class of antibodies (envelope dimer epitope 1 [EDE1]) that potently neutralizes ZIKV in addition to all four DENV serotypes points to a potential immunotherapeutic to combat ZIKV. This is especially salient given the precedent of antibody therapy to treat pregnant women infected with other viruses associated with microcephaly, such as cytomegalovirus and rubella virus. Furthermore, the identification of a functionally conserved epitope between ZIKV and DENV raises the possibility that a vaccine may be able to elicit neutralizing antibodies against both viruses.

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