Monoclonal antibodies and their target specificity against SARS-CoV-2 infections: Perspectives and challenges Short title: Monoclonal antibodies and SARS-CoV-2 infections

Abstract: The world continues to be in the midst of a distressing pandemic of coronavirus disease 2019 (COVID-19) infection caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a novel virus with multiple antigenic systems. The virus enters via nasopharynx, oral and infects cells by the expression of the spike protein, and enters the lungs using the angiotensin-converting enzyme-2 receptor. The spectrum of specific immune responses to SARS-CoV-2 virus infection is increasingly challenging as frequent mutations have been reported and their antigen specificity varies accordingly. The development of monoclonal antibodies (mAbs) will have a more significant advantage in suppressing SARS-CoV-2 virus infectivity. Recently, mAbs have been developed to target specific neutralizing antibodies against SARS-CoV-2 infection. The use of the therapeutic index of mAbs that can elicit neutralization by binding to the viral spike protein and suppress the cytokine network is a classic therapeutic approach for a potential cure. The development of mAbs against B-cell function as well as inhibition of the cytokine network has also been a focus in recent research. Recent studies have demonstrated the efficacy of mAbs as antibody cocktail preparations against SARS-CoV-2 infection. Target specific therapeutic accomplishment with mAbs, a milestone in the modern therapeutic age, can be used to achieve a specific therapeutic strategy to suppress SARS-CoV-2 virus infection. This review focuses on the molecular aspects of the cytokine network and antibody formation to better understand the development of mAbs against SARS-CoV-2 infection.

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Extremely potent monoclonal antibodies neutralize Omicron and other SARS-CoV-2 variants

10.1101/2022.01.12.22269023 ◽

2022 ◽

Author(s):

Zhaochun Chen ◽

Peng Zhang ◽

Yumiko Matsuoka ◽

Yaroslav Tsybovsky ◽

Kamille West ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Neutralizing Antibodies ◽

Spike Protein ◽

Structural Basis ◽

Hamster Model ◽

Golden Syrian Hamster ◽

Phage Display Libraries ◽

Antibody Phage ◽

Antibody Phage Display ◽

Early Isolate

The ongoing coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has triggered a devastating global health, social and economic crisis. The RNA nature and broad circulation of this virus facilitate the accumulation of mutations, leading to the continuous emergence of variants of concern with increased transmissibility or pathogenicity1. This poses a major challenge to the effectiveness of current vaccines and therapeutic antibodies1,2. Thus, there is an urgent need for effective therapeutic and preventive measures with a broad spectrum of action, especially against variants with an unparalleled number of mutations such as the recently emerged Omicron variant, which is rapidly spreading across the globe3. Here, we used combinatorial antibody phage-display libraries from convalescent COVID-19 patients to generate monoclonal antibodies against the receptor-binding domain of the SARS-CoV-2 spike protein with ultrapotent neutralizing activity. One such antibody, NE12, neutralizes an early isolate, the WA-1 strain, as well as the Alpha and Delta variants with half-maximal inhibitory concentrations at picomolar level. A second antibody, NA8, has an unusual breadth of neutralization, with picomolar activity against both the Beta and Omicron variants. The prophylactic and therapeutic efficacy of NE12 and NA8 was confirmed in preclinical studies in the golden Syrian hamster model. Analysis by cryo-EM illustrated the structural basis for the neutralization properties of NE12 and NA8. Potent and broadly neutralizing antibodies against conserved regions of the SARS-CoV-2 spike protein may play a key role against future variants of concern that evade immune control.

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Anti-drug antibodies to antibody-based therapeutics in multiple sclerosis

Human Antibodies ◽

10.3233/hab-210453 ◽

2021 ◽

pp. 1-9

Author(s):

David Baker ◽

A. Nazli Asardag ◽

Olivia A. Quinn ◽

Alex Efimov ◽

Angray S. Kang

Keyword(s):

Multiple Sclerosis ◽

Monoclonal Antibodies ◽

Remote Monitoring ◽

Neutralizing Antibodies ◽

Cell Function ◽

Treatment Cessation ◽

Human Antibodies ◽

The Central Nervous System ◽

Patient Responses ◽

B Cell Subsets

Multiple sclerosis is the major demyelinating autoimmune disease of the central nervous system. Relapsing MS can be treated by a number of approved monoclonal antibodies that currently target: CD20, CD25 (withdrawn), CD49d and CD52. These all target potentially pathogenic memory B cell subsets and perhaps functionally inhibit pathogenic T cell function. These consist of chimeric, humanized and fully human antibodies. However, despite humanization it is evident that all of these monoclonal antibodies can induce binding and neutralizing antibodies ranging from < 1% to over 80% within a year of treatment. Importantly, it is evident that monitoring these allow prediction of future treatment-failure in some individuals and treatment cessation and switching therefore potentially limiting disease breakthrough and disability accumulation. In response to the COVID-19 pandemic and the need to avoid hospitals, shortened infusion times and extended dose intervals have been implemented, importantly, subcutaneous delivery of alternative treatments or formulations have been developed to allow for home treatment. Therefore, hospital-based and remote monitoring of ADA could therefore be advantageous to optimize patient responses in the future.

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Neutralizing Monoclonal Antibodies That Target the Spike Receptor Binding Domain Confer Fc Receptor-Independent Protection against SARS-CoV-2 Infection in Syrian Hamsters

mBio ◽

10.1128/mbio.02395-21 ◽

2021 ◽

Author(s):

Wen Su ◽

Sin Fun Sia ◽

Aaron J. Schmitz ◽

Traci L. Bricker ◽

Tyler N. Starr ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Severe Acute Respiratory Syndrome ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Fc Receptor ◽

Spike Protein ◽

Receptor Binding Domain ◽

Syrian Hamsters ◽

Convalescent Phase ◽

Main Target

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein is the main target for neutralizing antibodies. These antibodies can be elicited through immunization or passively transferred as therapeutics in the form of convalescent-phase sera or monoclonal antibodies (MAbs).

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Structures of SARS-CoV-2 B.1.351 neutralizing antibodies provide insights into cocktail design against concerning variants

10.1101/2021.07.30.454402 ◽

2021 ◽

Author(s):

Shuo Du ◽

Pulan Liu ◽

Zhiying Zhang ◽

Tianhe Xiao ◽

Ayijiang Yasimayi ◽

...

Keyword(s):

Electron Microscopy ◽

Monoclonal Antibodies ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Antibody Responses ◽

Spike Protein ◽

Receptor Binding Domain ◽

Humoral Antibody ◽

Cryo Electron Microscopy ◽

Antibody Cocktail

The spread of the SARS-CoV-2 variants could seriously dampen the global effort to tackle the COVID-19 pandemic. Recently, we investigated the humoral antibody responses of SARS-CoV-2 convalescent patients and vaccinees towards circulating variants, and identified a panel of monoclonal antibodies (mAbs) that could efficiently neutralize the B.1.351 (Beta) variant. Here we investigate how these mAbs target the B.1.351 spike protein using cryo-electron microscopy. In particular, we show that two superpotent mAbs, BD-812 and BD-836, have non-overlapping epitopes on the receptor-binding domain (RBD) of spike. Both block the interaction between RBD and the ACE2 receptor; and importantly, both remain fully efficacious towards the B.1.617.1 (Kappa) and B.1.617.2 (Delta) variants. The BD-812/BD-836 pair could thus serve as an ideal antibody cocktail against the SARS-CoV-2 VOCs.

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SARS-CoV-2 501Y.V2 escapes neutralization by South African COVID-19 donor plasma

10.1101/2021.01.18.427166 ◽

2021 ◽

Cited By ~ 47

Author(s):

Constantinos Kurt Wibmer ◽

Frances Ayres ◽

Tandile Hermanus ◽

Mashudu Madzivhandila ◽

Prudence Kgagudi ◽

...

Keyword(s):

Monoclonal Antibodies ◽

South African ◽

Neutralizing Antibodies ◽

Spike Protein ◽

Donor Plasma

AbstractSARS-CoV-2 501Y.V2, a novel lineage of the coronavirus causing COVID-19, contains multiple mutations within two immunodominant domains of the spike protein. Here we show that this lineage exhibits complete escape from three classes of therapeutically relevant monoclonal antibodies. Furthermore 501Y.V2 shows substantial or complete escape from neutralizing antibodies in COVID-19 convalescent plasma. These data highlight the prospect of reinfection with antigenically distinct variants and may foreshadow reduced efficacy of current spike-based vaccines.

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Opsonization by non-neutralizing antibodies can confer protection to SARS-CoV-2 despite Spike-dependent modulation of phagocytosis

10.1101/2021.10.14.464464 ◽

2021 ◽

Author(s):

Wael Bahnan ◽

Sebastian Wrighton ◽

Martin Sundwall ◽

Anna Bläckberg ◽

Olivia Larsson ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Neutralizing Antibodies ◽

Antibody Binding ◽

Spike Protein ◽

Infection Model ◽

Immune Functions ◽

Immune Mechanism ◽

Neutralization Potential ◽

Specific Antibodies ◽

Low Levels

Spike-specific antibodies are central to effective COVID19 immunity. Research efforts have focused on antibodies that neutralize the ACE2-Spike interaction but not on non-neutralizing antibodies. Antibody-dependent phagocytosis is an immune mechanism enhanced by opsonization, where typically, more bound antibodies trigger a stronger phagocyte response. Here, we show that Spike-specific antibodies, dependent on concentration, can either enhance or reduce Spike-bead phagocytosis by monocytes independently of the antibody neutralization potential. Surprisingly, we find that both convalescent patient plasma and patient-derived monoclonal antibodies lead to maximum opsonization already at low levels of bound antibodies and is reduced as antibody binding to Spike protein increases. Moreover, we show that this Spike-dependent modulation of opsonization seems to affect the outcome in an experimental SARS-CoV-2 infection model. These results suggest that the levels of anti-Spike antibodies could influence monocyte-mediated immune functions and propose that non-neutralizing antibodies could confer protection to SARS-CoV-2 infection by mediating phagocytosis.

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Escape from neutralizing antibodies by SARS-CoV-2 spike protein variants

10.1101/2020.07.21.214759 ◽

2020 ◽

Cited By ~ 19

Author(s):

Yiska Weisblum ◽

Fabian Schmidt ◽

Fengwen Zhang ◽

Justin DaSilva ◽

Daniel Poston ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Spike Protein ◽

Receptor Binding Domain ◽

Reporter Virus ◽

Low Frequencies ◽

Protein Variants ◽

Prior Infection ◽

Neutralizing Epitopes

AbstractNeutralizing antibodies elicited by prior infection or vaccination are likely to be key for future protection of individuals and populations against SARS-CoV-2. Moreover, passively administered antibodies are among the most promising therapeutic and prophylactic anti-SARS-CoV-2 agents. However, the degree to which SARS-CoV-2 will adapt to evade neutralizing antibodies is unclear. Using a recombinant chimeric VSV/SARS-CoV-2 reporter virus, we show that functional SARS-CoV-2 S protein variants with mutations in the receptor binding domain (RBD) and N-terminal domain that confer resistance to monoclonal antibodies or convalescent plasma can be readily selected. Notably, SARS-CoV-2 S variants that resist commonly elicited neutralizing antibodies are now present at low frequencies in circulating SARS-CoV-2 populations. Finally, the emergence of antibody-resistant SARS-CoV-2 variants that might limit the therapeutic usefulness of monoclonal antibodies can be mitigated by the use of antibody combinations that target distinct neutralizing epitopes.

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The localized rise of a B.1.526 variant containing an E484K mutation in New York State

10.1101/2021.02.26.21251868 ◽

2021 ◽

Author(s):

Erica Lasek-Nesselquist ◽

Pascal Lapierre ◽

Erasmus Schneider ◽

Kirsten St. George ◽

Janice Pata

Keyword(s):

New York ◽

New York City ◽

Monoclonal Antibodies ◽

Metropolitan Area ◽

York City ◽

Neutralizing Antibodies ◽

Immune Escape ◽

New York State ◽

Spike Protein ◽

York State

The E484K mutation in the spike protein of SARS CoV-2 contributes to immune escape from monoclonal antibodies as well as neutralizing antibodies in COVID-19 convalescent plasma. It appears in two variants of concern: B.1.351 and P.1 but has evolved multiple times in different SARS-CoV-2 lineages, suggesting an adaptive advantage. Here we report on the emergence of a 484K variant in the B.1.526 lineage that has recently become prevalent in New York State, particularly in the New York City metropolitan area. In addition to the E484K mutation, these variants also harbor a D235G substitution in spike that might help to reduce the efficacy of neutralizing antibodies.

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Identification of neutralizing human monoclonal antibodies from Italian Covid-19 convalescent patients

10.1101/2020.05.05.078154 ◽

2020 ◽

Cited By ~ 12

Author(s):

Emanuele Andreano ◽

Emanuele Nicastri ◽

Ida Paciello ◽

Piero Pileri ◽

Noemi Manganaro ◽

...

Keyword(s):

Monoclonal Antibodies ◽

B Lymphocytes ◽

Neutralizing Antibodies ◽

Memory B Cells ◽

Spike Protein ◽

Human Monoclonal Antibodies ◽

Natural Production ◽

Development Pipeline ◽

Approved Drugs

ABSTRACTIn the absence of approved drugs or vaccines, there is a pressing need to develop tools for therapy and prevention of Covid-19. Human monoclonal antibodies have very good probability of being safe and effective tools for therapy and prevention of SARS-CoV-2 infection and disease. Here we describe the screening of PBMCs from seven people who survived Covid-19 infection to isolate human monoclonal antibodies against SARS-CoV-2. Over 1,100 memory B cells were single-cell sorted using the stabilized prefusion form of the spike protein and incubated for two weeks to allow natural production of antibodies. Supernatants from each cell were tested by ELISA for spike protein binding, and positive antibodies were further tested for neutralization of spike binding to receptor(s) on Vero E6 cells and for virus neutralization in vitro. From the 1,167 memory B specific for SARS-CoV-2, we recovered 318 B lymphocytes expressing human monoclonals recognizing the spike protein and 74 of these were able to inhibit the binding of the spike protein to the receptor. Finally, 17 mAbs were able to neutralize the virus when assessed for neutralization in vitro. Lead candidates to progress into the drug development pipeline will be selected from the panel of neutralizing antibodies identified with the procedure described in this study.One Sentence SummaryNeutralizing human monoclonal antibodies isolated from Covid-19 convalescent patients for therapeutic and prophylactic interventions.

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A human ex vivo dengue virus neutralization assay identifies priority antibodies and epitopes for vaccines and therapeutics

10.1101/516195 ◽

2019 ◽

Author(s):

Trung Tuan Vu ◽

Hannah Clapham ◽

Van Thi Thuy Huynh ◽

Long Vo Thi ◽

Dui Le Thi ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Dengue Virus ◽

Mammalian Cells ◽

Neutralizing Antibodies ◽

Neutralization Assay ◽

Virus Neutralization ◽

Virus Infectivity ◽

Virus Neutralization Assay ◽

The Impact ◽

Arboviral Disease

AbstractBackgroundDengue is the most prevalent arboviral disease, for which neither effective vaccines nor antivirals are available. Clinical trials with Dengvaxia, the first licensed dengue vaccine, show the conventional in vitro plaque reduction neutralization test (PRNT) failed to discriminate between neutralizing and non-neutralizing antibodies. A number of human monoclonal antibodies (mAbs) were characterized by PRNT as being neutralizers of virus infectivity for mammalian cells.Methodolody/Principle findingsWe developed a neutralization assay and tested the capacity of 12 mAbs to neutralize the infectiousness of dengue patient viremic blood in mosquitoes. We identified minimum concentrations of a subset of mAbs required to achieve dengue virus neutralization, and modelled the impact of a therapeutic mAb candidate on viremia.Five of the 12 mAbs (14c10, 2D22, 1L12, 747(4)B7, 753(3)C10), all of which target quaternary epitopes, potently inhibited dengue virus infection of Ae. aegypti. The potency of several mAbs was compromised in the context of patients with secondary serological profiles, possibly reflecting competition between the exogenously-added mAbs and the patient’s own antibody responses at or near the target epitopes. The minimum concentrations that mAbs neutralized DENV ranged from 0.1 – 5 µg/mL. An Fc-disabled variant of mAb (14c10-LALA) was as potent as its parent mAb. Within-host mathematical modelling suggests infusion of 14c10-LALA could bring about rapid acceleration of viremia resolution in a typical patient.Conclusions/SignificanceThese data delivered a unique assessment of anti-viral potency of a panel of human mAbs. Results support the advancement of dengue virus neutralization assays, and the development of therapeutics against flaviviruses, to which dengue virus and Zika virus belong.Author summaryDengue is the most prevalent arboviral disease affecting humans. There are no therapeutics for the disease. Antibody-mediated immunity against dengue is also not well-understood, as shown by the failure of the conventional neutralization assay used to predict the efficacy of Dengvaxia, the first licensed vaccine for the disease. It is likely that the neutralization assay targets non-neutralizing antibodies, but there are no validation assays available. To this end, we developed a novel virus neutralization assay, employing Aedes aegypti mosquitoes and viremic blood from dengue patients, to examine the virus-neutralizing potency of 12 human-derived monoclonal antibodies (mAbs). While all of these mAbs neutralized dengue virus using the conventional assay, seven of them failed to block dengue virus infections of mosquitoes using our assay. The remaining five mAbs neutralized at least one serotype of dengue virus and the minimum neutralizing concentrations of range from 0.1 – 5 µg/mL. Using the minimum neutralizing concentration of a therapeutic mAb candidate, we investigated the impact of the mAb on viremia using a mathematical model and found the mAb accelerated the reduction of viremia. The results support the advancement of dengue virus neutralization assays, and the development of therapeutics for dengue.

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