scholarly journals Engineered ACE2-Fc counters murine lethal SARS-CoV-2 infection through direct neutralization and Fc-effector activities

2021 ◽  
Author(s):  
Yaozong Chen ◽  
Lulu Sun ◽  
Irfan Ullah ◽  
Guillaume Beaudoin-Bussieres ◽  
Sai Priya Anand ◽  
...  
Keyword(s):  
Cellular Cytotoxicity ◽  
Therapeutic Activity ◽  
Converting Enzyme ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Angiotensin Converting Enzyme 2 ◽  
Effector Functions ◽  
Therapeutic Setting ◽  
Human Igg1 ◽  
Complement Deposition

Soluble Angiotensin-Converting Enzyme 2 (ACE2) constitutes an attractive antiviral receptor decoy that targets the vulnerable site on SARS-CoV-2 spike (S). Here, using structure-guided approaches, we developed divalent ACE2 molecules by grafting the extracellular ACE2-domain onto a human IgG1 or IgG3 (ACE2-Fc). These ACE2-Fcs harbored structurally validated mutations that enhance S binding and remove enzymatic activity. The lead variant bound tightly to S, mediated in vitro neutralization of SARS-CoV-2 variants of concern (VOCs) with sub-nanomolar IC50 and was capable of robust Fc-effector functions, including antibody-dependent cellular cytotoxicity, phagocytosis and complement deposition. When tested in a stringent K18-hACE2 mouse model, the lead variant prevented or delayed lethal SARS-CoV-2 infection in a prophylactic or therapeutic setting utilizing the combined effect of neutralization and Fc-effector functions. These data confirm the utility of ACE2-Fcs as valuable agents in preventing and eliminating SARS-CoV-2 infection and demonstrate that ACE2-Fc therapeutic activity require Fc-effector functions.

Engineering therapeutic antibodies for improved function

2002 ◽  
Vol 30 (4) ◽  
pp. 487-490 ◽  
Author(s):  
L. G. Presta ◽  
R. L. Shields ◽  
A. K. Namenuk ◽  
K. Hong ◽  
Y. G. Meng
Keyword(s):  
Binding Sites ◽  
Mononuclear Cells ◽  
Cellular Cytotoxicity ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Fcγ Receptor ◽  
Peripheral Blood Mononuclear ◽  
Adcc Assay ◽  
Human Igg1 ◽  
Improved Function

The binding sites on human IgG1 for human Fcγ receptor (FcγR) I, FcγRIIa, FcγRIIb, FcγRIIIa and neonatal FcR have been mapped. A common set of IgG1 residues is involved in binding to all FcγRs, while FcγRII and FcγRIII utilize distinct sites outside this common set. In addition to residues which abrogated binding to the FcγR, several positions were found which improved binding only to specific FcγRs or simultaneously improved binding to one type of FcγR and reduced binding to another type. Selected IgG1 variants with improved binding to FcγRIIIa were then tested in an in vitro antibody-dependent cellular cytotoxicity (ADCC) assay and showed an enhancement in ADCC when either peripheral blood mononuclear cells or natural killer cells were used.

scholarly journals Enhancement of antibody-dependent cellular cytotoxicity and phagocytosis in anti‐HIV‐1 bovine chimeric broadly-neutralizing antibodies.

2021 ◽  
Author(s):  
Jack M Edwards ◽  
Behnaz Heydarchi ◽  
Georges Khoury ◽  
Natalia A Salazar-Quiroz ◽  
Christopher A Gonelli ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Variable Region ◽  
Cellular Cytotoxicity ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Broadly Neutralizing Antibodies ◽  
Effector Functions ◽  
Human Igg1 ◽  
Topical Microbicides ◽  
Anti Hiv ◽  
Hiv 1

No prophylactic vaccine has provided robust protection against HIV-1. Vaccine-induced broadly neutralizing antibodies (bnAbs) have not been achieved in humans and most animals, however cows vaccinated with HIV-1 envelope trimers produce bnAbs with unusually long third heavy complementarity determining regions (CDRH3). Alongside neutralization, Fc-mediated effector functions including antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADP) may be critical for in vivo bnAb antiviral activity. Here, we aimed to augment the Fc-dependent effector functions of a chimeric human-bovine bnAb, NC-Cow1, which binds the CD4 binding site (CD4bs) and exhibits broader and more potent neutralization than most human CD4bs bnAbs by using an exceptionally long 60aa CDRH3. The bovine variable region of NC-Cow1 was paired with a human IgG1 Fc region mutated to create three variants: G236R/L328R (GRLR) that abrogates Fc-gamma receptor (FcγR) binding, and two variants that enhance binding: G236A/S239D/I332E (GASDIE) and G236A/S239D/A330L/I332E (GASDALIE). Both GASDIE and GASDALIE improved binding to human FcγRIIA and FcγRIIIA, enhanced human NK cell activation and mediated higher levels of ADCC and ADP activity compared to the wild-type human IgG1 Fc. GASDALIE mediated higher phagocytic activity compared to GASDIE. As expected, GRLR eliminated binding to FcγRs and did not mediate ADCC or ADP. We demonstrated that mutations in the human Fc region of bovine chimeric antibodies with ultra-long CDRH3 regions could enhance antibody effector functions while maintaining envelope binding and neutralization. This study will have significant implications in the development of multifunctional anti-HIV antibodies, which may be important to prevent HIV-1 transmission in an antibody-based topical microbicide. IMPORTANCE Despite successful antiviral chemotherapy, HIV is still a lifelong persistent virus and no vaccine yet prevents HIV transmission. Topical microbicides offer an important alternative method to prevent sexual transmission of HIV-1. With the production of highly potent anti-HIV-1 bnAbs and multifunctional antibodies, monoclonal antibodies are now important prophylactic agents. Recently discovered anti-HIV-1 bovine bnAbs (with higher potency and breadth than most human bnAbs) could be novel candidates as potent topical microbicides. Our study is significant as it demonstrates the compatibility of combining bovine-derived neutralization with human-derived antibody-effector functions. This study is a new approach to antibody engineering that strengthens the feasibility of using high potency bovine variable region bnAbs with augmented Fc function and promotes them as a strong candidate for antibody-mediated therapies.

scholarly journals ACE2-targeting monoclonal antibody as potent and broad-spectrum coronavirus blocker

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Yuning Chen ◽  
Ya-Nan Zhang ◽  
Renhong Yan ◽  
Guifeng Wang ◽  
Yuanyuan Zhang ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Broad Spectrum ◽  
Management Strategy ◽  
Spectrum Management ◽  
Clinical Development ◽  
Severe Toxicity ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Binding Residues

AbstractThe evolution of coronaviruses, such as SARS-CoV-2, makes broad-spectrum coronavirus preventional or therapeutical strategies highly sought after. Here we report a human angiotensin-converting enzyme 2 (ACE2)-targeting monoclonal antibody, 3E8, blocked the S1-subunits and pseudo-typed virus constructs from multiple coronaviruses including SARS-CoV-2, SARS-CoV-2 mutant variants (SARS-CoV-2-D614G, B.1.1.7, B.1.351, B.1.617.1, and P.1), SARS-CoV and HCoV-NL63, without markedly affecting the physiological activities of ACE2 or causing severe toxicity in ACE2 “knock-in” mice. 3E8 also blocked live SARS-CoV-2 infection in vitro and in a prophylactic mouse model of COVID-19. Cryo-EM and “alanine walk” studies revealed the key binding residues on ACE2 interacting with the CDR3 domain of 3E8 heavy chain. Although full evaluation of safety in non-human primates is necessary before clinical development of 3E8, we provided a potentially potent and “broad-spectrum” management strategy against all coronaviruses that utilize ACE2 as entry receptors and disclosed an anti-coronavirus epitope on human ACE2.

scholarly journals Virtual screening as therapeutic strategy of COVID-19 targeting angiotensin-converting enzyme 2

2021 ◽  
Vol 2 (1) ◽  
pp. 16-27
Author(s):  
Zahra Sharifinia ◽  
◽  
Samira Asadi ◽  
Mahyar Irani ◽  
Abdollah Allahverdi ◽  
...  
Keyword(s):  
Virtual Screening ◽  
Angiotensin Converting Enzyme ◽  
Host Cells ◽  
Spike Protein ◽  
Potential Drug ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Approved Drugs ◽  
Fda Approved Drugs

Objective: The receptor-binding domain (RBD) of the S1 domain of the SARS-CoV- 2 Spike protein performs a key role in the interaction with Angiotensin-converting enzyme 2 (ACE2), leading to both subsequent S2 domain-mediated membrane fusion and incorporation of viral RNA in host cells. Methods: In this study, we investigated the inhibitor’s targeted compounds through existing human ACE2 drugs to use as a future viral invasion. 54 FDA approved drugs were selected to assess their binding affinity to the ACE2 receptor. The structurebased methods via computational ones have been used for virtual screening of the best drugs from the drug database. Key Findings: The ligands “Cinacalcet” and “Levomefolic acid” highaffinity scores can be a potential drug preventing Spike protein of SARS-CoV-2 and human ACE2 interaction. Levomefolic acid from vitamin B family was proved to be a potential drug as a spike protein inhibitor in previous clinical and computational studies. Besides that, in this study, the capability of Levomefolic acid to avoid ACE2 and Spike protein of SARS-CoV-2 interaction is indicated. Therefore, it is worth to consider this drug for more in vitro investigations as ACE2 and Spike protein inhibition candidate. Conclusion: The two Cinacalcet and Levomefolic acid are the two ligands that have highest energy binding for human ACE2 blocking among 54 FDA approved drugs.

DOCKING STUDY OF NOVEL N-SUBSTITUTED 2,5-BIS[(7-CHLOROQUINOLIN-4-YL)AMINO]PENTANOIC DERIVATIVES AS SELECTIVE HIGH-BINDER WITH ANGIOTENSIN CONVERTING ENZYME 2

INDIAN DRUGS ◽  
2020 ◽  
Vol 57 (08) ◽  
pp. 16-24
Author(s):  
Mohammed Oday Ezzat ◽  
Basma M. Abd Razik ◽  
Kutayba F. Dawood
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Active Site ◽  
Docking Study ◽  
World Health ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Pharmaceutical Properties ◽  
Novel Coronavirus

The prevalence of a novel coronavirus (2019-nCoV) in the last few months represents a serious threat as a world health emergency concern. Angiotensin-converting enzyme 2 (ACE2) is the host cellular receptor for the respiratory syndrome of coronavirus epidemic in 2019 (2019-nCoV). In this work, the active site of ACE2 is successfully located by Sitmap prediction tool and validated by different marketed drugs. To design and discover new medical countermeasure drugs, we evaluate a total of 184 molecules of 7-chloro-N-methylquinolin-4-amine derivatives for binding affinity inside the crystal structure of ACE2 located active site. A novel series of N-substituted 2,5-bis[(7-chloroquinolin-4-yl)amino]pentanoic acid derivatives is generated and evaluated for a prospect as a lead compound for (2019-nCoV) medication with a docking score range of (-10.60 to -8.99) kcal/mol for the highest twenty derivatives. Moreover, the ADME pharmaceutical properties were evaluated for further proposed experimental evaluation in vitro or in vivo

scholarly journals Uremic Apelin and Leucocytic Angiotensin-Converting Enzyme 2 in CKD Patients

Toxins ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 742
Author(s):  
Bogusz Trojanowicz ◽  
Christof Ulrich ◽  
Matthias Girndt
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Healthy Controls ◽  
Converting Enzyme ◽  
Blood Pressure Lowering ◽  
Angiotensin Converting Enzyme 2 ◽  
Pressure Lowering ◽  
The Impact ◽  
Progression Of Atherosclerosis

Apelin peptides (APLN) serve as second substrates for angiotensin-converting enzyme 2 (ACE2) and, in contrast to angiotensin II (AngII), exert blood-pressure lowering and vasodilatation effects through binding to G-coupled APLN receptor (APLNR). ACE2-mediated cleavage of the APLN may reduce its vasodilatory effects, but decreased ACE2 may potentiate the hypotensive properties of APLN. The role of APLN in uremia is unclear. We investigated the correlations between serum-APLN, leucocytic APLNR, and ACE2 in 32 healthy controls (NP), 66 HD, and 24 CKD3–5 patients, and the impact of APLN peptides on monocytic behavior and ACE2 expression under uremic conditions in vitro. We observed that serum APLN and leucocytic APLNR or SLCO2B1 were significantly elevated in uremic patients and correlated with decreased ACE2 on uremic leucocytes. APLN-treated THP-1 monocytes revealed significantly increased APLNR and ACE2, and reduced TNFa, IL-6, and MCSF. Uremic toxins induced a dramatic increase of miR-421 followed by significant reduction of ACE2 transcripts, partially counteracted with APLN-13 and -36. APLN-36 triggered the most potent transmigration and reduction of endothelial adhesion. These results suggest that although APLN peptides may partly protect against the decay of monocytic ACE2 transcripts, uremic milieu is the most dominant modulator of local ACE2, and likely to contribute to the progression of atherosclerosis.

scholarly journals Development of Plant-Produced Recombinant ACE2-Fc Fusion Protein as a Potential Therapeutic Agent Against SARS-CoV-2

2021 ◽  
Vol 11 ◽  
Author(s):  
Konlavat Siriwattananon ◽  
Suwimon Manopwisedjaroen ◽  
Phongthon Kanjanasirirat ◽  
Priyo Budi Purwono ◽  
Kaewta Rattanapisit ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Vero Cells ◽  
Global Public Health ◽  
Potential Threat ◽  
Angiotensin Converting Enzyme 2 ◽  
Therapeutic Drugs ◽  
Fc Fusion Protein ◽  
Huge Impact ◽  
Human Igg1

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease (COVID-19) which has recently emerged as a potential threat to global public health. SARS-CoV-2 is the third known human coronavirus that has huge impact on the human population after SARS-CoV and MERS-CoV. Although some vaccines and therapeutic drugs are currently in clinical trials, none of them are approved for commercial use yet. As with SARS-CoV, SARS-CoV-2 utilizes angiotensin-converting enzyme 2 (ACE2) as the cell entry receptor to enter into the host cell. In this study, we have transiently produced human ACE2 fused with the Fc region of human IgG1 in Nicotiana benthamiana and the in vitro neutralization efficacy of the plant-produced ACE2-Fc fusion protein was assessed. The recombinant ACE2-Fc fusion protein was expressed in N. benthamiana at 100 μg/g leaf fresh weight on day 6 post-infiltration. The recombinant fusion protein showed potent binding to receptor binding domain (RBD) of SARS-CoV-2. Importantly, the plant-produced fusion protein exhibited potent anti-SARS-CoV-2 activity in vitro. Treatment with ACE2-Fc fusion protein after viral infection dramatically inhibit SARS-CoV-2 infectivity in Vero cells with an IC50 value of 0.84 μg/ml. Moreover, treatment with ACE2-Fc fusion protein at the pre-entry stage suppressed SARS-CoV-2 infection with an IC50 of 94.66 μg/ml. These findings put a spotlight on the plant-produced ACE2-Fc fusion protein as a potential therapeutic candidate against SARS-CoV-2.

scholarly journals Malignant monoblasts can function as effector cells in natural killer cell and antibody-dependent cellular cytotoxicity assays

Blood ◽  
1981 ◽  
Vol 57 (5) ◽  
pp. 972-974 ◽  
Author(s):  
P Hokland ◽  
M Hokland ◽  
J Ellegaard
Keyword(s):  
Natural Killer ◽  
Killer Cell ◽  
Present Knowledge ◽  
In Vitro Cultures ◽  
Cellular Cytotoxicity ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Effector Cells ◽  
Cytotoxicity Assays ◽  
Acute Monoblastic Leukemia

Abstract This is the first report describing natural killer (NK) and antibody- dependent cellular cytotoxicity (ADCC) of malignant monoblasts. Pure acute monoblastic leukemia was diagnosed in bone marrow aspirations from two patients by use of conventional cytochemical methods as well as multiple immunologic techniques including detection of ALL antigens and terminal transferase. The malignant cells were subsequently found to be potent effectors in NK and ADCC assays. Addition of partially purified alpha-interferon to the in vitro cultures was found to have an enhancing effect on NK activity, whereas no modulation was seen in ADCC. These findings are discussed in the light of our present knowledge of lymphoid NK cells.

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