scholarly journals Increased resistance of SARS-CoV-2 Omicron Variant to Neutralization by Vaccine-Elicited and Therapeutic Antibodies

2021 ◽  
Author(s):  
Takuya Tada ◽  
Hao Zhou ◽  
Belinda M Dcosta ◽  
Marie I Samanovic ◽  
Vidya Chivukula ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Disease Severity ◽  
Spike Protein ◽  
Therapeutic Antibodies ◽  
Relative Resistance ◽  
Vaccine Protection ◽  
Booster Immunization

Currently authorized vaccines for SARS-CoV-2 have been highly successful in preventing infection and lessening disease severity. The vaccines maintain effectiveness against SARS-CoV-2 Variants of Concern but the heavily mutated, highly transmissible Omicron variant poses an obstacle both to vaccine protection and monoclonal antibody therapies. Analysis of the neutralization of Omicron spike protein-pseudotyped lentiviruses showed a 26-fold relative resistance (compared to D614G) to neutralization by convalescent sera and 26-34-fold resistance to Pfizer BNT162b2 and Moderna vaccine-elicited antibodies following two immunizations. A booster immunization increased neutralizing titers against Omicron by 6-8-fold. Previous SARS-CoV-2 infection followed by vaccination resulted in the highest neutralizing titers against Omicron. Regeneron REGN10933 and REGN10987, and Lilly LY-CoV555 and LY-CoV016 monoclonal antibodies were ineffective against Omicron, while Sotrovimab was partially effective. The results highlight the benefit of a booster immunization in providing protection against Omicron but demonstrate the challenge to monoclonal antibody therapies.

scholarly journals SARS-CoV-2 variants resist antibody neutralization and broaden host ACE2 usage

2021 ◽  
Author(s):  
Ruoke Wang ◽  
Qi Zhang ◽  
Jiwan Ge ◽  
Wenlin Ren ◽  
Rui Zhang ◽  
...  
Keyword(s):  
South Africa ◽  
Monoclonal Antibodies ◽  
Molecular Basis ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Antibody Neutralization ◽  
Vaccine Protection ◽  
Antigenic Sites ◽  
Global Pandemic ◽  
Crystal Structural

AbstractNew SARS-CoV-2 variants continue to emerge from the current global pandemic, some of which can replicate faster and with greater transmissibility and pathogenicity. In particular, UK501Y.V1 identified in UK, SA501Y.V2 in South Africa, and BR501Y.V3 in Brazil are raising serious concerns as they spread quickly and contain spike protein mutations that may facilitate escape from current antibody therapies and vaccine protection. Here, we constructed a panel of 28 SARS-CoV-2 pseudoviruses bearing single or combined mutations found in the spike protein of these three variants, as well as additional nine mutations that within or close by the major antigenic sites in the spike protein identified in the GISAID database. These pseudoviruses were tested against a panel of monoclonal antibodies (mAbs), including some approved for emergency use to treat SARS-CoV-2 infection, and convalescent patient plasma collected early in the pandemic. SA501Y.V2 pseudovirus was the most resistant, in magnitude and breadth, against mAbs and convalescent plasma, followed by BR501Y.V3, and then UK501Y.V1. This resistance hierarchy corresponds with Y144del and 242-244del mutations in the N-terminal domain as well as K417N/T, E484K and N501Y mutations in the receptor binding domain (RBD). Crystal structural analysis of RBD carrying triple K417N-E484K-N501Y mutations found in SA501Y.V2 bound with mAb P2C-1F11 revealed a molecular basis for antibody neutralization and escape. SA501Y.V2 and BR501Y.V3 also acquired substantial ability to use mouse and mink ACE2 for entry. Taken together, our results clearly demonstrate major antigenic shifts and potentially broadening the host range of SA501Y.V2 and BR501Y.V3, which pose serious challenges to our current antibody therapies and vaccine protection.

scholarly journals Key substitutions in the spike protein of SARS-CoV-2 variants can predict resistance to monoclonal antibodies, but other substitutions can modify the effects

2021 ◽  
Author(s):  
Sabrina Lusvarghi ◽  
Wei Wang ◽  
Rachel Herrup ◽  
Sabari Nath Neerukonda ◽  
Russell Vassell ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Receptor Binding ◽  
Clinical Stage ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Therapeutic Antibodies ◽  
Epistatic Interactions ◽  
Neutralization Activity ◽  
Virus Susceptibility

Mutations in the spike protein of SARS-CoV-2 variants can compromise the effectiveness of therapeutic antibodies. Most clinical-stage therapeutic antibodies target the spike receptor binding domain (RBD), but variants often have multiple mutations in several spike regions. To help predict antibody potency against emerging variants, we evaluated 25 clinical-stage therapeutic antibodies for neutralization activity against 60 pseudoviruses bearing spikes with single or multiple substitutions in several spike domains, including the full set of substitutions in B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.429 (Epsilon), B.1.526 (Iota), A.23.1 and R.1 variants. We found that 14 of 15 single antibodies were vulnerable to at least one RBD substitution, but most combination and polyclonal therapeutic antibodies remained potent. Key substitutions in variants with multiple spike substitutions predicted resistance, but the degree of resistance could be modified in unpredictable ways by other spike substitutions that may reside outside of the RBD. These findings highlight the importance of assessing antibody potency in the context of all substitutions in a variant and show that epistatic interactions in spike can modify virus susceptibility to therapeutic antibodies.

scholarly journals B.1.526 SARS-CoV-2 Variants Identified in New York City are Neutralized by Vaccine-Elicited and Therapeutic Monoclonal Antibodies

mBio ◽  
2021 ◽  
Author(s):  
Hao Zhou ◽  
Belinda M. Dcosta ◽  
Marie I. Samanovic ◽  
Mark J. Mulligan ◽  
Nathaniel R. Landau ◽  
...  
Keyword(s):  
New York ◽  
Monoclonal Antibody ◽  
New York City ◽  
Monoclonal Antibodies ◽  
York City ◽  
Antibody Therapy ◽  
Spike Protein ◽  
Monoclonal Antibody Therapy ◽  
Therapeutic Monoclonal Antibodies

A novel SARS-CoV-2 variant termed B.1.526 was recently identified in New York City and has been found to be spreading at an alarming rate. The variant has mutations in its spike protein that might allow it to escape neutralization by vaccine-elicited antibodies and might cause monoclonal antibody therapy for COVID-19 to be less successful.

scholarly journals The Spike Proteins of SARS-CoV-2 B.1.617 and B.1.618 Variants Identified in India Provide Partial Resistance to Vaccine-elicited and Therapeutic Monoclonal Antibodies.

2021 ◽  
Author(s):  
Takuya Tada ◽  
Hao Zhou ◽  
Belinda M Dcosta ◽  
Marie I Samanovic ◽  
Mark J Mulligan ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Partial Resistance ◽  
Spike Protein ◽  
Therapeutic Monoclonal Antibodies ◽  
Antibody Cocktail ◽  
Spike Proteins

Highly transmissible SARS-CoV-2 variants recently identified in India designated B.1.617 and B.1.618 have mutations within the spike protein that may contribute to their increased transmissibility and that could potentially result in re-infection or resistance to vaccine-elicited antibody. B.1.617 encodes a spike protein with mutations L452R, E484Q, D614G and P681R while the B.1.618 spike has mutations Δ145-146, E484K and D614G. We generated lentiviruses pseudotyped by the variant proteins and determined their resistance to neutralization by convalescent sera, vaccine-elicited antibodies and therapeutic monoclonal antibodies. Viruses with B.1.617 and B.1.618 spike were neutralized with a 2-5-fold decrease in titer by convalescent sera and vaccine-elicited antibodies. The E484Q and E484K versions were neutralized with a 2-4-fold decrease in titer. Virus with the B.1.617 spike protein was neutralized with a 4.7-fold decrease in titer by the Regeneron monoclonal antibody cocktail as a result of the L452R mutation. The modest neutralization resistance of the variant spike proteins to vaccine elicited antibody suggests that current vaccines will remain protective against the B.1.617 and B.1.618 variants.

Nascent chains: folding and chaperone interaction during elongation on ribosomes

1995 ◽  
Vol 348 (1323) ◽  
pp. 89-95 ◽  
Keyword(s):  
Escherichia Coli ◽  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Spike Protein ◽  
Tryptophan Synthase ◽  
Bacteriophage P22 ◽  
Folding Intermediates ◽  
Tail Spike ◽  
Polypeptide Chains

Monoclonal antibodies that detect folding intermediates in vitro were used to monitor the appearance of folded polypeptide chains during their synthesis on the ribosomes. Nascent immunoreactive chains of the bacteriophage P22 tail-spike protein and of the Escherichia coli β 2 subunit of tryptophan-synthase were thus identified, suggesting that they can fold on the ribosomes. Moreover, the immunoreactivity of ribosome- bound tryptophan-synthase β-chains of intermediate lengths was shown to appear with no detectable delay compared to their synthesis. This suggested that β-chains start folding during their elongation on the ribosomes. However, newly synthesized incomplete β-chains were shown to interact with chaperones while still bound to the ribosome. Because of the peculiar properties of the epitope recognized by the anti- tryptophan-synthase monoclonal antibody used, it could not be concluded whether the immunoreactivity of the nascent β-chains resulted from their ability to fold cotranslationally or from their association with chaperones which might maintain them in an unfolded, immunoreactive state.

Rapid quantification and in situ detection of nitrifying bacteria in biofilms by monoclonal antibody method

2000 ◽  
Vol 41 (4-5) ◽  
pp. 301-308 ◽  
Author(s):  
N. Noda ◽  
H. Ikuta ◽  
Y. Ebie ◽  
A. Hirata ◽  
S. Tsuneda ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Fluorescent Antibody ◽  
Nitrifying Bacteria ◽  
Fluorescent Antibody Technique ◽  
Antibody Technique ◽  
Antibody Method ◽  
In Situ Detection ◽  
Rapid Quantification

Fluorescent antibody technique by the monoclonal antibody method is very useful and helpful for the rapid quantification and in situ detection of the specific bacteria like nitrifiers in a mixed baxterial habitat such as a biofilm. In this study, twelve monoclonal antibodies against Nitrosomonas europaea (IFO14298) and sixteen against Nitrobacter winogradskyi (IFO14297) were raised from splenocytes of mice (BALB/c). It was found that these antibodies exhibited little cross reactivity against various kinds of heterotrophic bacteria. The direct cell count method using monoclonal antibodies could exactly detect and rapidly quantify N. europaea and N. winogradskyi. Moreover, the distribution of N. europaea and N. winogradskyi in a biofilm could be examined by in situ fluorescent antibody technique. It was shown that most of N. winogradskyi existed near the surface part and most of N. europaea existed at the inner part of the polyethylene glycol (PEG) gel pellet, which had entrapped activated sludge and used in a landfill leachate treatment reactor. It was suggested that this monoclonal antibody method was utilized for estimating and controlling the population of nitrifying bacteria as a quick and favorable tool.

Therapeutic Monoclonal Antibodies in Clinical Practice against Cancer

2020 ◽  
Vol 20 (16) ◽  
pp. 1895-1907
Author(s):  
Navgeet Kaur ◽  
Anju Goyal ◽  
Rakesh K. Sindhu
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Clinical Practice ◽  
Therapeutic Agent ◽  
Hematologic Malignancies ◽  
Immune Checkpoints ◽  
Malignant Cells ◽  
Main Target ◽  
Therapeutic Monoclonal Antibodies ◽  
Cancerous Cells

The importance of monoclonal antibodies in oncology has increased drastically following the discovery of Milstein and Kohler. Since the first approval of the monoclonal antibody, i.e. Rituximab in 1997 by the FDA, there was a decline in further applications but this number has significantly increased over the last three decades for various therapeutic applications due to the lesser side effects in comparison to the traditional chemotherapy methods. Presently, numerous monoclonal antibodies have been approved and many are in queue for approval as a strong therapeutic agent for treating hematologic malignancies and solid tumors. The main target checkpoints for the monoclonal antibodies against cancer cells include EGFR, VEGF, CD and tyrosine kinase which are overexpressed in malignant cells. Other immune checkpoints like CTLA-4, PD-1 and PD-1 receptors targeted by the recently developed antibodies increase the capability of the immune system in destroying the cancerous cells. Here, in this review, the mechanism of action, uses and target points of the approved mAbs against cancer have been summarized.

Evaluation of the Efficiency of Protein A Affinity Chromatography to Purify a Monoclonal Antibody for Cancer Treatment and its Purity Analysis

2020 ◽  
Vol 7 (2) ◽  
pp. 121-133
Author(s):  
Ayesha Akhtar ◽  
Shivakumar Arumugam ◽  
Shoaib Alam
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Affinity Chromatography ◽  
Protein A ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
High Yield ◽  
Staphylococcal Protein A ◽  
Purification Step ◽  
Purity Analysis

Background:: Protein A affinity chromatography is often employed as the most crucial purification step for monoclonal antibodies to achieve high yield with purity and throughput requirements. Introduction:: Protein A, also known as Staphylococcal protein A (SPA) is found in the cell wall of the bacteria staphylococcus aureus. It is one of the first discovered immunoglobulin binding molecules and has been extensively studied since the past few decades. The efficiency of Protein A affinity chromatography to purify a recombinant monoclonal antibody in a cell culture sample has been evaluated, which removes 99.0% of feed stream impurities. Materials and Method:: We have systematically evaluated the purification performance by using a battery of analytical methods SDS-PAGE (non-reduced and reduced sample), Cation Exchange Chromatography (CEX), Size-exclusion chromatography (SEC), and Reversed phased-Reduced Chromatography for a CHO-derived monoclonal antibody. Results and Discussion:: The analytical test was conducted to determine the impurity parameter, Host Cell Contaminating Proteins (HCP). It was evaluated to be 0.015ng/ml after the purification step; while initially, it was found to be 24.431ng/ml. Conclusion:: The tests showed a distinct decrease in the level of different impurities after the chromatography step. It can be concluded that Protein A chromatography is an efficient step in the purification of monoclonal antibodies.

scholarly journals Development of a New Highly Selective Monoclonal Antibody against Preferentially Expressed Antigen in Melanoma (PRAME) and Identification of the Target Epitope by Bio-Layer Interferometry

2021 ◽  
Vol 22 (6) ◽  
pp. 3166
Author(s):  
Jwala Priyadarsini Sivaccumar ◽  
Antonio Leonardi ◽  
Emanuela Iaccarino ◽  
Giusy Corvino ◽  
Luca Sanguigno ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Western Blotting ◽  
Cancer Biomarkers ◽  
Trypsin Digestion ◽  
Protein Fragments ◽  
Target Epitope ◽  
Potential Activity ◽  
Antibody Epitopes

Background: Monoclonal antibodies (mAbs) against cancer biomarkers are key reagents in diagnosis and therapy. One such relevant biomarker is a preferentially expressed antigen in melanoma (PRAME) that is selectively expressed in many tumors. Knowing mAb’s epitope is of utmost importance for understanding the potential activity and therapeutic prospective of the reagents. Methods: We generated a mAb against PRAME immunizing mice with PRAME fragment 161–415; the affinity of the antibody for the protein was evaluated by ELISA and SPR, and its ability to detect the protein in cells was probed by cytofluorimetry and Western blotting experiments. The antibody epitope was identified immobilizing the mAb on bio-layer interferometry (BLI) sensor chip, capturing protein fragments obtained following trypsin digestion and performing mass spectrometry analyses. Results: A mAb against PRAME with an affinity of 35 pM was obtained and characterized. Its epitope on PRAME was localized on residues 202–212, taking advantage of the low volumes and lack of fluidics underlying the BLI settings. Conclusions: The new anti-PRAME mAb recognizes the folded protein on the surface of cell membranes suggesting that the antibody’s epitope is well exposed. BLI sensor chips can be used to identify antibody epitopes.

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