scholarly journals Exceptionally Potent Neutralization of Middle East Respiratory Syndrome Coronavirus by Human Monoclonal Antibodies

2014 ◽  
Vol 88 (14) ◽  
pp. 7796-7805 ◽  
Author(s):  
Tianlei Ying ◽  
Lanying Du ◽  
Tina W. Ju ◽  
Ponraj Prabakaran ◽  
Candy C. Y. Lau ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Middle East ◽  
High Mortality ◽  
Dissociation Constants ◽  
Rapid Identification ◽  
Middle East Respiratory Syndrome ◽  
Site Directed Mutagenesis ◽  
Antibody Library ◽  
Human Monoclonal Antibodies ◽  
Receptor Binding Site

ABSTRACTThe recently discovered Middle East respiratory syndrome coronavirus (MERS-CoV) continues to infect humans, with high mortality. Specific, highly effective therapeutics and vaccines against the MERS-CoV are urgently needed to save human lives and address the pandemic concerns. We identified three human monoclonal antibodies (MAbs), m336, m337, and m338, targeting the receptor (CD26/DPP4) binding domain (RBD) of the MERS-CoV spike glycoprotein from a very large naïve-antibody library (containing ∼1011antibodies). They bound with high affinity: equilibrium dissociation constants for the three MAbs were equal to 4.2, 9.3, and 15 nM, respectively, as measured by Biacore for Fabs binding to RBD. The avidity for IgG1 m336, m337, and m338 was even higher: 99, 820, and 560 pM, respectively. The antibodies bound to overlapping epitopes that overlap the receptor binding site on the RBD as suggested by competition experiments and further supported by site-directed mutagenesis of the RBD and a docking model of the m336-RBD complex. The highest-affinity MAb, m336, neutralized both pseudotyped and live MERS-CoV with exceptional potency, 50% neutralization at 0.005 and 0.07 μg/ml, respectively, likely by competing with DPP4 for binding to the S glycoprotein. The exceptionally high neutralization activity of these antibodies and especially m336 suggests that they have great potential for prophylaxis and therapy of MERS-CoV infection in humans and as a tool for development of vaccine immunogens. The rapid identification (within several weeks) of potent MAbs suggests a possibility to use the new large antibody library and related methodology for a quick response to the public threat resulting from emerging coronaviruses.IMPORTANCEA novel human coronavirus, the Middle East respiratory syndrome coronavirus (MERS-CoV), was found to infect humans with a high mortality rate in 2012, just 1 decade after the appearance of the first highly pathogenic coronavirus, severe acute respiratory syndrome coronavirus (SARS-CoV). There are no effective therapeutics available. It is highly desirable to find an approach for rapidly developing potent therapeutics against MERS-CoV, which not only can be implemented for MERS treatment but also can help to develop a platform strategy to combat future emerging coronaviruses. We report here the identification of human monoclonal antibodies (MAbs) from a large nonimmune antibody library that target MERS-CoV. One of the antibodies, m336, neutralized the virus with exceptional potency. It therefore may have great potential as a candidate therapeutic and as a reagent to facilitate the development of vaccines against MERS-CoV.

scholarly journals Characterization of Two Human Monoclonal Antibodies Neutralizing Influenza A H7N9 Viruses

2015 ◽  
Vol 89 (17) ◽  
pp. 9115-9118 ◽  
Author(s):  
Jianmin Wang ◽  
Zhe Chen ◽  
Linlin Bao ◽  
Weijia Zhang ◽  
Ying Xue ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Global Health ◽  
Influenza A ◽  
Severe Infection ◽  
Health Concern ◽  
Phage Library ◽  
Human Monoclonal Antibodies ◽  
Receptor Binding Site ◽  
Antibody Phage

H7N9 was a cause of significant global health concern due to its severe infection and approximately 35% mortality in humans. By screening a Fab antibody phage library derived from patients who recovered from H7N9 infections, we characterized two human monoclonal antibodies (HuMAbs), HNIgGD5 and HNIgGH8. The epitope of these two antibodies was dependent on two residues in the receptor binding site at positions V186 and L226 of the hemagglutinin glycoprotein. Both antibodies possessed high neutralizing activity.

Analysis of binding residues in monoclonal antibody with high affinity for the head domain of the rat P2X4 receptor

2020 ◽  
Author(s):  
Tatsuhiro Igawa ◽  
Shuhei Kishikawa ◽  
Yoshito Abe ◽  
Makoto Tsuda ◽  
Kazuhide Inoue ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Neuropathic Pain ◽  
Monoclonal Antibodies ◽  
Dissociation Constants ◽  
Site Directed Mutagenesis ◽  
P2x4 Receptor ◽  
High Affinity ◽  
Head Domain ◽  
Binding Residues ◽  
Nanomolar Range

Abstract P2X4 receptor is known to be involved in neuropathic pain. In order to detect the expression of P2X4 receptor on microglia at the time of onset of neuropathic pain, one approach consists on the preparation of the monoclonal antibodies with both selective binding and high affinity. We have recently established a monoclonal antibody (named 12-10H) which had high affinity to rat P2X4 receptor expressed in 1321N1 cells. The dissociation constants of the complex between the monoclonal antibodies obtained so far and the head domain (HD) in the rat P2X4 receptor were in the nanomolar range. To improve the affinity by rational mutations, we need to know the precious location of the binding site in these monoclonal antibodies. Here, we have analysed and identified the binding residues in the monoclonal antibody (12-10H) with high affinity for the HD of the rat P2X4 receptor by site-directed mutagenesis.

scholarly journals Identification and Characterization of Human Monoclonal Antibodies for Immunoprophylaxis against EnterotoxigenicEscherichia coliInfection

2018 ◽  
Vol 86 (8) ◽  
Author(s):  
Serena Giuntini ◽  
Matteo Stoppato ◽  
Maja Sedic ◽  
Monir Ejemel ◽  
Jessica R. Pondish ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Oral Administration ◽  
Secretory Iga ◽  
Watery Diarrhea ◽  
Human Monoclonal Antibodies ◽  
Receptor Binding Site ◽  
Content Type ◽  
Colonization Factor ◽  
Etec Infection

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) causes diarrheal illness in infants in the developing world and travelers to countries where the disease is endemic, including military personnel. ETEC infection of the host involves colonization of the small intestinal epithelium and toxin secretion, leading to watery diarrhea. There is currently no vaccine licensed to prevent ETEC infection. CFA/I is one of the most common colonization factor antigens (CFAs). The CFA/I adhesin subunit, CfaE, is required for ETEC adhesion to host intestinal cells. Human antibodies against CfaE have the potential to block colonization of ETEC and serve as an immunoprophylactic against ETEC-related diarrhea. Mice transgenic for human immunoglobulin genes were immunized with CfaE to generate a panel of human monoclonal IgG1 antibodies (HuMAbs). The most potent IgG1 antibodies identified in thein vitrofunctional assays were selected and isotype switched to secretory IgA (sIgA) and tested in animal colonization assays via oral administration. Over 300 unique anti-CfaE IgG1 HuMAbs were identified. The lead IgG1 anti-CfaE HuMAbs completely inhibited hemagglutination and blocked adhesion of ETEC to Caco-2 cells. Epitope mapping studies revealed that HuMAbs recognized epitopes in the N-terminal domain of CfaE near the putative receptor binding site. Oral administration of anti-CfaE antibodies in either IgG or sIgA isotypes inhibited intestinal colonization in mice challenged with ETEC. A 2- to 4-log decrease in CFU was observed in comparison to mice challenged with irrelevant isotype controls. We identified fully human monoclonal antibodies against the CfaE adhesion domain that can be potentially employed as an immunoprophylactic to prevent ETEC-related diarrhea.

scholarly journals Selection and Characterization of Monoclonal Antibodies Targeting Middle East Respiratory Syndrome Coronavirus through a Human Synthetic Fab Phage Display Library Panning

Antibodies ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 42 ◽  
Author(s):  
Kim ◽  
Lee ◽  
Park ◽  
Park ◽  
Lim ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Monoclonal Antibodies ◽  
Middle East ◽  
Phage Display ◽  
Medical Center ◽  
Point Of Care ◽  
Phage Display Library ◽  
Cross Reactivity ◽  
Middle East Respiratory Syndrome ◽  
High Morbidity

Since its first report in the Middle East in 2012, the Middle East respiratory syndrome-coronavirus (MERS-CoV) has become a global concern due to the high morbidity and mortality of individuals infected with the virus. Although the majority of MERS-CoV cases have been reported in Saudi Arabia, the overall risk in areas outside the Middle East remains significant as inside Saudi Arabia. Additional pandemics of MERS-CoV are expected, and thus novel tools and reagents for therapy and diagnosis are urgently needed. Here, we used phage display to develop novel monoclonal antibodies (mAbs) that target MERS-CoV. A human Fab phage display library was panned against the S2 subunit of the MERS-CoV spike protein (MERS-S2P), yielding three unique Fabs (S2A3, S2A6, and S2D5). The Fabs had moderate apparent affinities (Half maximal effective concentration (EC50 = 123–421 nM) for MERS-S2P, showed no cross-reactivity to spike proteins from other CoVs, and were non-aggregating and thermostable (Tm = 61.5–80.4 °C). Reformatting the Fabs into IgGs (Immunoglobulin Gs) greatly increased their apparent affinities (KD = 0.17–1.2 nM), presumably due to the effects of avidity. These apparent affinities were notably higher than that of a previously reported anti-MERS-CoV S2 reference mAb (KD = 8.7 nM). Furthermore, two of the three mAbs (S2A3 and S2D5) bound only MERS-CoV (Erasmus Medical Center (EMC)) and not other CoVs, reflecting their high binding specificity. However, the mAbs lacked MERS-CoV neutralizing activity. Given their high affinity, specificity, and desirable stabilities, we anticipate that these anti-MERS-CoV mAbs would be suitable reagents for developing antibody-based diagnostics in laboratory or hospital settings for point-of-care testing.

scholarly journals Coronavirus vaccine development: from SARS and MERS to COVID-19

2020 ◽  
Vol 27 (1) ◽  
Author(s):  
Yen-Der Li ◽  
Wei-Yu Chi ◽  
Jun-Han Su ◽  
Louise Ferrall ◽  
Chien-Fu Hung ◽  
...  
Keyword(s):  
Middle East ◽  
Severe Acute Respiratory Syndrome ◽  
High Mortality ◽  
Recent Progress ◽  
Vaccine Development ◽  
Middle East Respiratory Syndrome ◽  
Effective Vaccine ◽  
Rapid Spread ◽  
New Type ◽  
Pros And Cons

AbstractSevere Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a new type of coronavirus that causes the Coronavirus Disease 2019 (COVID-19), which has been the most challenging pandemic in this century. Considering its high mortality and rapid spread, an effective vaccine is urgently needed to control this pandemic. As a result, the academia, industry, and government sectors are working tightly together to develop and test a variety of vaccines at an unprecedented pace. In this review, we outline the essential coronavirus biological characteristics that are important for vaccine design. In addition, we summarize key takeaways from previous vaccination studies of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV), highlighting the pros and cons of each immunization strategy. Finally, based on these prior vaccination experiences, we discuss recent progress and potential challenges of COVID-19 vaccine development.

scholarly journals Neutralizing Monoclonal Antibodies as Promising Therapeutics against Middle East Respiratory Syndrome Coronavirus Infection

Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 680 ◽  
Author(s):  
Hui-Ju Han ◽  
Jian-Wei Liu ◽  
Hao Yu ◽  
Xue-Jie Yu
Keyword(s):  
Monoclonal Antibodies ◽  
Middle East ◽  
Middle East Respiratory Syndrome ◽  
Global Public Health ◽  
Emerging Viruses ◽  
Passive Immunotherapy ◽  
Worldwide Distribution ◽  
High Fatality Rate ◽  
Coronavirus Infection ◽  
Review Current

Since emerging in 2012, Middle East Respiratory Syndrome Coronavirus (MERS-CoV) has been a global public health threat with a high fatality rate and worldwide distribution. There are no approved vaccines or therapies for MERS until now. Passive immunotherapy with neutralizing monoclonal antibodies (mAbs) is an effective prophylactic and therapeutic reagent against emerging viruses. In this article, we review current advances in neutralizing mAbs against MERS-CoV. The receptor-binding domain (RBD) in the spike protein of MERS-CoV is a major target, and mouse, camel, or human-derived neutralizing mAbs targeting RBD have been developed. A major problem with neutralizing mAb therapy is mutant escape under selective pressure, which can be solved by combination of neutralizing mAbs targeting different epitopes. Neutralizing mAbs are currently under preclinical evaluation, and they are promising candidate therapeutic agents against MERS-CoV infection.

scholarly journals Importance of Neutralizing Monoclonal Antibodies Targeting Multiple Antigenic Sites on the Middle East Respiratory Syndrome Coronavirus Spike Glycoprotein To Avoid Neutralization Escape

2018 ◽  
Vol 92 (10) ◽  
Author(s):  
Lingshu Wang ◽  
Wei Shi ◽  
James D. Chappell ◽  
M. Gordon Joyce ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Middle East ◽  
Receptor Binding ◽  
Binding Domain ◽  
Middle East Respiratory Syndrome ◽  
Health Concern ◽  
Immunoglobulin Gene ◽  
Receptor Binding Domain ◽  
Spike Glycoprotein ◽  
Antigenic Sites

ABSTRACT Middle East respiratory syndrome coronavirus (MERS-CoV) causes a highly lethal pulmonary infection with ∼35% mortality. The potential for a future pandemic originating from animal reservoirs or health care-associated events is a major public health concern. There are no vaccines or therapeutic agents currently available for MERS-CoV. Using a probe-based single B cell cloning strategy, we have identified and characterized multiple neutralizing monoclonal antibodies (MAbs) specifically binding to the receptor-binding domain (RBD) or S1 (non-RBD) regions from a convalescent MERS-CoV-infected patient and from immunized rhesus macaques. RBD-specific MAbs tended to have greater neutralizing potency than non-RBD S1-specific MAbs. Six RBD-specific and five S1-specific MAbs could be sorted into four RBD and three non-RBD distinct binding patterns, based on competition assays, mapping neutralization escape variants, and structural analysis. We determined cocrystal structures for two MAbs targeting the RBD from different angles and show they can bind the RBD only in the “out” position. We then showed that selected RBD-specific, non-RBD S1-specific, and S2-specific MAbs given prophylactically prevented MERS-CoV replication in lungs and protected mice from lethal challenge. Importantly, combining RBD- and non-RBD MAbs delayed the emergence of escape mutations in a cell-based virus escape assay. These studies identify MAbs targeting different antigenic sites on S that will be useful for defining mechanisms of MERS-CoV neutralization and for developing more effective interventions to prevent or treat MERS-CoV infections. IMPORTANCE MERS-CoV causes a highly lethal respiratory infection for which no vaccines or antiviral therapeutic options are currently available. Based on continuing exposure from established reservoirs in dromedary camels and bats, transmission of MERS-CoV into humans and future outbreaks are expected. Using structurally defined probes for the MERS-CoV spike glycoprotein (S), the target for neutralizing antibodies, single B cells were sorted from a convalescent human and immunized nonhuman primates (NHPs). MAbs produced from paired immunoglobulin gene sequences were mapped to multiple epitopes within and outside the receptor-binding domain (RBD) and protected against lethal MERS infection in a murine model following passive immunization. Importantly, combining MAbs targeting distinct epitopes prevented viral neutralization escape from RBD-directed MAbs. These data suggest that antibody responses to multiple domains on CoV spike protein may improve immunity and will guide future vaccine and therapeutic development efforts.

scholarly journals Production and characterisation of deletion mutants of ovine growth hormone

1999 ◽  
Vol 23 (1) ◽  
pp. 97-106 ◽  
Author(s):  
AJ Sami ◽  
OC Wallis ◽  
M Wallis
Keyword(s):  
Growth Hormone ◽  
Monoclonal Antibodies ◽  
Receptor Binding ◽  
Polyclonal Antibody ◽  
Binding Activity ◽  
Site Directed Mutagenesis ◽  
Terminal Sequence ◽  
Receptor Binding Site ◽  
Receptor Binding Activity ◽  
Epitope Binding

A number of analogues of ovine growth hormone (GH), in which regions of the hormone had been deleted, were produced by site-directed mutagenesis, and characterised by radioimmunoassays and radioreceptor assays. These analogues were based on a previously described variant (oGH1) in which an 8-residue extension replaces the N-terminal alanine of pituitary-derived ovine GH. Three analogues with deletions near the N-terminus were studied, with shorter extensions of 7 or 1-2 residues (oGH14, oGH5) or with the N-terminal sequence Ala-Phe-Pro- of pituitary-derived ovine GH replaced by Thr-Met-Ile-Thr- (oGH11). These modifications had little effect on potency in radioimmunoassays based on a polyclonal antibody and five different monoclonal antibodies (MABs), or in a radioreceptor assay, indicating that the N-terminal sequence was not included in the epitope binding to any of the monoclonal antibodies, or a major epitope binding to the polyclonal antibody, or in receptor binding site 1. A variant in which residues 133-139 were deleted retained full binding to 4 of the 5 MABs, suggesting correct folding, but markedly reduced binding to MAB OA16, suggesting that the epitope for this MAB includes some or all of these residues. This variant also failed to displace about 35% of labelled hormone from the polyclonal antibody studied, suggesting that residues 133-139 may be involved in a major epitope for this antibody. This variant showed slightly lower receptor binding activity than ovine GH. Two other deletion variants - oGH1Delta33-46 (equivalent to the naturally occurring 20K variant of human GH) and oGH1Delta180-191 (lacking the C-terminal 12 residues) showed poor folding efficiency and solubility, and low binding to all MABs except OA15, which has a linear epitope. The results suggest that these variants were incorrectly folded, but interestingly they did retain some activity in the receptor-binding assay (respectively about 5% and 0.5% of the activity of ovine GH itself).

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