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1.
Chin Med J (Engl) ; 134(16): 1967-1976, 2021 07 22.
Article in English | MEDLINE | ID: covidwho-1769434

ABSTRACT

BACKGROUND: Innovative coronavirus disease 2019 (COVID-19) vaccines, with elevated global manufacturing capacity, enhanced safety and efficacy, simplified dosing regimens, and distribution that is less cold chain-dependent, are still global imperatives for tackling the ongoing pandemic. A previous phase I trial indicated that the recombinant COVID-19 vaccine (V-01), which contains a fusion protein (IFN-PADRE-RBD-Fc dimer) as its antigen, is safe and well tolerated, capable of inducing rapid and robust immune responses, and warranted further testing in additional clinical trials. Herein, we aimed to assess the immunogenicity and safety of V-01, providing rationales of appropriate dose regimen for further efficacy study. METHODS: A randomized, double-blind, placebo-controlled phase II clinical trial was initiated at the Gaozhou Municipal Centre for Disease Control and Prevention (Guangdong, China) in March 2021. Both younger (n = 440; 18-59 years of age) and older (n = 440; ≥60 years of age) adult participants in this trial were sequentially recruited into two distinct groups: two-dose regimen group in which participants were randomized either to follow a 10 or 25 µg of V-01 or placebo given intramuscularly 21 days apart (allocation ratio, 3:3:1, n = 120, 120, 40 for each regimen, respectively), or one-dose regimen groups in which participants were randomized either to receive a single injection of 50 µg of V-01 or placebo (allocation ratio, 3:1, n = 120, 40, respectively). The primary immunogenicity endpoints were the geometric mean titers of neutralizing antibodies against live severe acute respiratory syndrome coronavirus 2, and specific binding antibodies to the receptor binding domain (RBD). The primary safety endpoint evaluation was the frequencies and percentages of overall adverse events (AEs) within 30 days after full immunization. RESULTS: V-01 provoked substantial immune responses in the two-dose group, achieving encouragingly high titers of neutralizing antibody and anti-RBD immunoglobulin, which peaked at day 35 (161.9 [95% confidence interval [CI]: 133.3-196.7] and 149.3 [95%CI: 123.9-179.9] in 10 and 25 µg V-01 group of younger adults, respectively; 111.6 [95%CI: 89.6-139.1] and 111.1 [95%CI: 89.2-138.4] in 10 and 25 µg V-01 group of older adults, respectively), and remained high at day 49 after a day-21 second dose; these levels significantly exceed those in convalescent serum from symptomatic COVID-19 patients (53.6, 95%CI: 31.3-91.7). Our preliminary data show that V-01 is safe and well tolerated, with reactogenicity predominantly being absent or mild in severity and only one vaccine-related grade 3 or worse AE being observed within 30 days. The older adult participants demonstrated a more favorable safety profile compared with those in the younger adult group: with AEs percentages of 19.2%, 25.8%, 17.5% in older adults vs. 34.2%, 23.3%, 26.7% in younger adults at the 10, 25 µg V-01 two-dose group, and 50 µg V-01 one-dose group, respectively. CONCLUSIONS: The vaccine candidate V-01 appears to be safe and immunogenic. The preliminary findings support the advancement of the two-dose, 10 µg V-01 regimen to a phase III trial for a large-scale population-based evaluation of safety and efficacy. TRIAL REGISTRATION: http://www.chictr.org.cn/index.aspx (No. ChiCTR2100045107, http://www.chictr.org.cn/showproj.aspx?proj=124702).


Subject(s)
COVID-19 , Aged , Antibodies, Viral , COVID-19/therapy , COVID-19 Vaccines , Double-Blind Method , Humans , Immunization, Passive , Recombinant Fusion Proteins , SARS-CoV-2
2.
Viruses ; 14(4)2022 03 22.
Article in English | MEDLINE | ID: covidwho-1753696

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic caused by infection of SARS-CoV-2 and its variants has posed serious threats to global public health, thus calling for the development of potent and broad-spectrum antivirals. We previously designed and developed a peptide-based pan-coronavirus (CoV) fusion inhibitor, EK1, which is effective against all human CoVs (HCoV) tested by targeting the HCoV S protein HR1 domain. However, its relatively short half-life may limit its clinical use. Therefore, we designed, constructed, and expressed a recombinant protein, FL-EK1, which consists of a modified fibronectin type III domain (FN3) with albumin-binding capacity, a flexible linker, and EK1. As with EK1, we found that FL-EK1 could also effectively inhibit infection of SARS-CoV-2 and its variants, as well as HCoV-OC43. Furthermore, it protected mice from infection by the SARS-CoV-2 Delta variant and HCoV-OC43. Importantly, the half-life of FL-EK1 (30 h) is about 15.7-fold longer than that of EK1 (1.8 h). These results suggest that FL-EK1 is a promising candidate for the development of a pan-CoV fusion inhibitor-based long-acting antiviral drug for preventing and treating infection by current and future SARS-CoV-2 variants, as well as other HCoVs.


Subject(s)
COVID-19 , SARS-CoV-2 , Viral Fusion Protein Inhibitors , Animals , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , COVID-19/drug therapy , Coronavirus Infections/drug therapy , Fibronectin Type III Domain , Half-Life , Mice , Recombinant Fusion Proteins , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/metabolism , Viral Fusion Protein Inhibitors/chemistry , Viral Fusion Protein Inhibitors/pharmacology
4.
Orphanet J Rare Dis ; 17(1): 78, 2022 02 23.
Article in English | MEDLINE | ID: covidwho-1714660

ABSTRACT

BACKGROUND: Hypophosphatasia (HPP) is a rare inherited metabolic disorder caused by mutations in the ALPL gene, which encodes tissue nonspecific alkaline phosphatase. The severity of HPP is widely diverse from the perinatal form to the adult mild form. The former represents the most severe form and was earlier associated with high mortality due to pneumonia which was caused by severe hypomineralization of the bones-such as chest deformity and fractured ribs-and muscle weakness. Enzyme replacement therapy using asfotase alfa (AA) was approved in 2015 in Japan for treating patients with HPP and has improved their pulmonary function and life prognosis. There are several practical and ethical challenges related to using orphan drugs for a rare disorder in a publicly funded healthcare system. Sharing experiences about their application is essential towards formulating guidelines to assist clinicians with decisions about their initiation and withdrawal. We report the details of AA experience in ten cases of pediatric-onset HPP in nine families from January 2015 to November 2019 (median [interquartile range] age 11.0 [7.6-12.5] years; 60% male). This is a study of a single-center cohort describing the clinical course of patients with HPP, mainly consisting of the mild childhood form of HPP, treated with AA in Japan. RESULTS: One case of perinatal form of HPP, two cases of benign prenatal form, and seven cases of childhood form were observed. The most common symptom at onset was pain. All patients had low serum alkaline phosphatase levels as compared to the age-matched reference range before the commencement of AA. All HPP patients seem to have responded to AA treatment, as evidenced by pain alleviation, increased height standard deviation, improvement in respiratory condition and 6-min walk test result improvement, disappearance of kidney calcification, alleviation of fatigue, and/or increases in bone mineralization. There were no serious adverse events, but all patients had an injection site reaction and skin changes at the injection sites. Genetic analysis showed that eight out of ten patients had compound heterozygosity. CONCLUSIONS: AA may be effective in patients with mild to severe pediatric-onset forms of HPP.


Subject(s)
Hypophosphatasia , Adult , Alkaline Phosphatase/genetics , Child , Female , Humans , Hypophosphatasia/complications , Hypophosphatasia/drug therapy , Immunoglobulin G , Japan , Male , Pain/drug therapy , Rare Diseases/drug therapy , Recombinant Fusion Proteins
5.
J Virol ; 96(4): e0162221, 2022 02 23.
Article in English | MEDLINE | ID: covidwho-1706888

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can induce mild to life-threatening symptoms. Especially individuals over 60 years of age or with underlying comorbidities, including heart or lung disease and diabetes, or immunocompromised patients are at a higher risk. Fatal multiorgan damage in coronavirus disease 2019 (COVID-19) patients can be attributed to an interleukin-6 (IL-6)-dominated cytokine storm. Consequently, IL-6 receptor (IL-6R) monoclonal antibody treatment for severe COVID-19 cases has been approved for therapy. High concentrations of soluble IL-6R (sIL-6R) were found in COVID-19 intensive care unit patients, suggesting the involvement of IL-6 trans-signaling in disease pathology. Here, in analogy to bispecific antibodies (bsAbs), we developed the first bispecific IL-6 trans-signaling inhibitor, c19s130Fc, which blocks viral infection and IL-6 trans-signaling. c19s130Fc is a designer protein of the IL-6 trans-signaling inhibitor cs130 fused to a single-domain nanobody directed against the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. c19s130Fc binds with high affinity to IL-6:sIL-6R complexes as well as the spike protein of SARS-CoV-2, as shown by surface plasmon resonance. Using cell-based assays, we demonstrate that c19s130Fc blocks IL-6 trans-signaling-induced proliferation and STAT3 phosphorylation in Ba/F3-gp130 cells as well as SARS-CoV-2 infection and STAT3 phosphorylation in Vero cells. Taken together, c19s130Fc represents a new class of bispecific inhibitors consisting of a soluble cytokine receptor fused to antiviral nanobodies and principally demonstrates the multifunctionalization of trans-signaling inhibitors. IMPORTANCE The availability of effective SARS-CoV-2 vaccines is a large step forward in managing the pandemic situation. In addition, therapeutic options, e.g., monoclonal antibodies to prevent viral cell entry and anti-inflammatory therapies, including glucocorticoid treatment, are currently developed or in clinical use to treat already infected patients. Here, we report a novel dual-specificity inhibitor to simultaneously target SARS-CoV-2 infection and virus-induced hyperinflammation. This was achieved by fusing an inhibitor of viral cell entry with a molecule blocking IL-6, a key mediator of SARS-CoV-2-induced hyperinflammation. Through this dual action, this molecule may have the potential to efficiently ameliorate symptoms of COVID-19 in infected individuals.


Subject(s)
COVID-19 , Cytokine Receptor gp130 , Interleukin-6/metabolism , Recombinant Fusion Proteins , Signal Transduction/drug effects , Single-Domain Antibodies , Spike Glycoprotein, Coronavirus/metabolism , Animals , COVID-19/drug therapy , COVID-19/metabolism , Chlorocebus aethiops , Cytokine Receptor gp130/chemistry , Cytokine Receptor gp130/genetics , Humans , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/pharmacology , Single-Domain Antibodies/chemistry , Single-Domain Antibodies/genetics , Single-Domain Antibodies/pharmacology , Vero Cells
6.
Commun Biol ; 5(1): 152, 2022 02 22.
Article in English | MEDLINE | ID: covidwho-1701655

ABSTRACT

The complement system constitutes the innate defense against pathogens. Its dysregulation leads to diseases and is a critical determinant in many viral infections, e.g., COVID-19. Factor H (FH) is the main regulator of the alternative pathway of complement activation and could be a therapy to restore homeostasis. However, recombinant FH is not available. Engineered FH versions may be alternative therapeutics. Here, we designed a synthetic protein, MFHR13, as a multitarget complement regulator. It combines the dimerization and C5-regulatory domains of human FH-related protein 1 (FHR1) with the C3-regulatory and cell surface recognition domains of human FH, including SCR 13. In summary, the fusion protein MFHR13 comprises SCRs FHR11-2:FH1-4:FH13:FH19-20. It protects sheep erythrocytes from complement attack exhibiting 26 and 4-fold the regulatory activity of eculizumab and human FH, respectively. Furthermore, we demonstrate that MFHR13 and FHR1 bind to all proteins forming the membrane attack complex, which contributes to the mechanistic understanding of FHR1. We consider MFHR13 a promising candidate as therapeutic for complement-associated diseases.


Subject(s)
Blood Proteins/metabolism , Complement Activation , Complement Factor H/metabolism , Complement System Proteins/metabolism , Erythrocytes/metabolism , Recombinant Fusion Proteins/metabolism , Amino Acid Sequence , Animals , Bryopsida/genetics , Bryopsida/metabolism , COVID-19/epidemiology , COVID-19/metabolism , COVID-19/virology , Complement Membrane Attack Complex/metabolism , Humans , Models, Molecular , Pandemics/prevention & control , Protein Binding , Protein Conformation , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , SARS-CoV-2/physiology , Sheep
7.
Front Immunol ; 12: 734279, 2021.
Article in English | MEDLINE | ID: covidwho-1686469

ABSTRACT

Newly emerging variants of coronavirus 2 (SARS-CoV-2) raise concerns about the spread of the disease, and with the rising case numbers, the Coronavirus disease 2019 (COVID-19) remains a challenging medical emergency towards the end of the year 2021. Swiftly developed novel vaccines aid in the prevention of the spread, and it seems that a specific cure will not be at hand soon. The prognosis of COVID-19 in patients with autoimmune/autoinflammatory rheumatic diseases (AIIRD) is more severe when compared to the otherwise healthy population, and vaccination is essential. Evidence for both the efficacy and safety of COVID-19 vaccination in AIIRD under immunosuppression is accumulating, but the effect of Interleukin-1 on vaccination in general and in AIIRD patients is rarely addressed in the current literature. In light of the current literature, it seems that the level of agreement on the timing of COVID-19 vaccination is moderate in patients using IL-1 blockers, and expert opinions may vary. Generally, it may be recommended that patients under IL-1 blockade can be vaccinated without interrupting the anti-cytokine therapy, especially in patients with ongoing high disease activity to avoid disease relapses. However, in selected cases, after balancing for disease activity and risk of relapses, vaccination may be given seven days after the drug levels have returned to baseline, especially for IL-1 blocking agents with long half-lives such as canakinumab and rilonacept. This may help to ensure an ideal vaccine response in the face of the possibility that AIIRD patients may develop a more pronounced and severe COVID-19 disease course.


Subject(s)
Antirheumatic Agents/adverse effects , COVID-19 Vaccines/immunology , COVID-19/prevention & control , Interleukin-1beta/antagonists & inhibitors , Rheumatic Diseases/drug therapy , SARS-CoV-2/immunology , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/therapeutic use , Antirheumatic Agents/therapeutic use , Autoimmune Diseases/drug therapy , Autoimmune Diseases/immunology , Humans , Immunosuppressive Agents/adverse effects , Immunosuppressive Agents/therapeutic use , Recombinant Fusion Proteins/adverse effects , Recombinant Fusion Proteins/therapeutic use , Rheumatic Diseases/immunology , Vaccination
8.
Signal Transduct Target Ther ; 7(1): 44, 2022 02 09.
Article in English | MEDLINE | ID: covidwho-1683982

ABSTRACT

The wide transmission and host adaptation of SARS-CoV-2 have led to the rapid accumulation of mutations, posing significant challenges to the effectiveness of vaccines and therapeutic antibodies. Although several neutralizing antibodies were authorized for emergency clinical use, convalescent patients derived natural antibodies are vulnerable to SARS-CoV-2 Spike mutation. Here, we describe the screen of a panel of SARS-CoV-2 receptor-binding domain (RBD) targeted nanobodies (Nbs) from a synthetic library and the design of a biparatopic Nb, named Nb1-Nb2, with tight affinity and super-wide neutralization breadth against multiple SARS-CoV-2 variants of concern. Deep-mutational scanning experiments identify the potential binding epitopes of the Nbs on the RBD and demonstrate that biparatopic Nb1-Nb2 has a strong escape-resistant feature against more than 60 tested RBD amino acid substitutions. Using pseudovirion-based and trans-complementation SARS-CoV-2 tools, we determine that the Nb1-Nb2 broadly neutralizes multiple SARS-CoV-2 variants at sub-nanomolar levels, including Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), Lambda (C.37), Kappa (B.1.617.1), and Mu (B.1.621). Furthermore, a heavy-chain antibody is constructed by fusing the human IgG1 Fc to Nb1-Nb2 (designated as Nb1-Nb2-Fc) to improve its neutralization potency, yield, stability, and potential half-life extension. For the new Omicron variant (B.1.1.529) that harbors unprecedented multiple RBD mutations, Nb1-Nb2-Fc keeps a firm affinity (KD < 1.0 × 10-12 M) and strong neutralizing activity (IC50 = 1.46 nM for authentic Omicron virus). Together, we developed a tetravalent biparatopic human heavy-chain antibody with ultrapotent and broad-spectrum SARS-CoV-2 neutralization activity which highlights the potential clinical applications.


Subject(s)
Antibodies, Neutralizing/pharmacology , Antibodies, Viral/pharmacology , Immunoglobulin Fc Fragments/pharmacology , Recombinant Fusion Proteins/pharmacology , SARS-CoV-2/drug effects , Single-Domain Antibodies/pharmacology , Antibodies, Neutralizing/biosynthesis , Antibodies, Neutralizing/genetics , Antibodies, Viral/biosynthesis , Antibodies, Viral/genetics , Antibody Affinity , Enzyme-Linked Immunosorbent Assay , Epitopes/chemistry , Epitopes/immunology , Escherichia coli/genetics , Escherichia coli/metabolism , Gene Expression , Humans , Immunoglobulin Fc Fragments/biosynthesis , Immunoglobulin Fc Fragments/genetics , Models, Molecular , Neutralization Tests , Protein Binding/drug effects , Protein Conformation , Protein Interaction Domains and Motifs , Recombinant Fusion Proteins/biosynthesis , Recombinant Fusion Proteins/genetics , SARS-CoV-2/growth & development , SARS-CoV-2/immunology , Single-Domain Antibodies/biosynthesis , Single-Domain Antibodies/genetics , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
9.
Biomolecules ; 12(2)2022 02 08.
Article in English | MEDLINE | ID: covidwho-1674481

ABSTRACT

Ribonuclease inhibitors (RIs) are an indispensable biotechnological tool for the detection and manipulation of RNA. Nowadays, due to the outbreak of COVID-19, highly sensitive detection of RNA has become more important than ever. Although the recombinant expression of RNase inhibitors is possible in E. coli, the robust expression is complicated by maintaining the redox potential and solubility by various expression tags. In the present paper we describe the expression of RI in baculovirus-infected High Five cells in large scale utilizing a modified transfer vector combining the beneficial properties of Profinity Exact Tag and pONE system. The recombinant RI is expressed at a high level in a fusion form, which is readily cleaved during on-column chromatography. A subsequent anion exchange chromatography was used as a polishing step to yield 12 mg native RI per liter of culture. RI expressed in insect cells shows higher thermal stability than the commercially available RI products (mainly produced in E. coli) based on temperature-dependent RNase inhibition studies. The endotoxin-free RI variant may also be applied in future therapeutics as a safe additive to increase mRNA stability in mRNA-based vaccines.


Subject(s)
Insecta/genetics , Insecta/metabolism , Placental Hormones/biosynthesis , Recombinant Fusion Proteins/biosynthesis , Animals , Enzyme Stability , Humans , Placental Hormones/isolation & purification , Placental Hormones/metabolism , Plasmids , Recombinant Fusion Proteins/isolation & purification , Recombinant Fusion Proteins/metabolism , Temperature
10.
J Allergy Clin Immunol ; 149(2): 557-561.e1, 2022 02.
Article in English | MEDLINE | ID: covidwho-1670624

ABSTRACT

BACKGROUND: Patients with some types of immunodeficiency can experience chronic or relapsing infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This leads to morbidity and mortality, infection control challenges, and the risk of evolution of novel viral variants. The optimal treatment for chronic coronavirus disease 2019 (COVID-19) is unknown. OBJECTIVE: Our aim was to characterize a cohort of patients with chronic or relapsing COVID-19 disease and record treatment response. METHODS: We conducted a UK physician survey to collect data on underlying diagnosis and demographics, clinical features, and treatment response of immunodeficient patients with chronic (lasting ≥21 days) or relapsing (≥2 episodes) of COVID-19. RESULTS: We identified 31 patients (median age 49 years). Their underlying immunodeficiency was most commonly characterized by antibody deficiency with absent or profoundly reduced peripheral B-cell levels; prior anti-CD20 therapy, and X-linked agammaglobulinemia. Their clinical features of COVID-19 were similar to those of the general population, but their median duration of symptomatic disease was 64 days (maximum 300 days) and individual patients experienced up to 5 episodes of illness. Remdesivir monotherapy (including when given for prolonged courses of ≤20 days) was associated with sustained viral clearance in 7 of 23 clinical episodes (30.4%), whereas the combination of remdesivir with convalescent plasma or anti-SARS-CoV-2 mAbs resulted in viral clearance in 13 of 14 episodes (92.8%). Patients receiving no therapy did not clear SARS-CoV-2. CONCLUSIONS: COVID-19 can present as a chronic or relapsing disease in patients with antibody deficiency. Remdesivir monotherapy is frequently associated with treatment failure, but the combination of remdesivir with antibody-based therapeutics holds promise.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Antibodies, Monoclonal/therapeutic use , Antiviral Agents/therapeutic use , COVID-19/therapy , Immunologic Deficiency Syndromes/therapy , SARS-CoV-2/drug effects , Adenosine Monophosphate/therapeutic use , Adult , Aged , Aged, 80 and over , Alanine/therapeutic use , B-Lymphocytes/immunology , B-Lymphocytes/pathology , COVID-19/immunology , COVID-19/pathology , COVID-19/virology , Chronic Disease , Female , Humans , Immunization, Passive , Immunologic Deficiency Syndromes/immunology , Immunologic Deficiency Syndromes/pathology , Immunologic Deficiency Syndromes/virology , Lymphocyte Count , Male , Middle Aged , Recombinant Fusion Proteins/administration & dosage , Recurrence , SARS-CoV-2/pathogenicity , Treatment Failure
11.
Microb Cell Fact ; 21(1): 21, 2022 Feb 05.
Article in English | MEDLINE | ID: covidwho-1666655

ABSTRACT

We have developed a method for the inexpensive, high-level expression of antigenic protein fragments of SARS-CoV-2 proteins in Escherichia coli. Our approach uses the thermophilic family 9 carbohydrate-binding module (CBM9) as an N-terminal carrier protein and affinity tag. The CBM9 module was joined to SARS-CoV-2 protein fragments via a flexible proline-threonine linker, which proved to be resistant to E. coli proteases. Two CBM9-spike protein fragment fusion proteins and one CBM9-nucleocapsid fragment fusion protein largely resisted protease degradation, while most of the CBM9 fusion proteins were degraded at some site in the SARS-CoV-2 protein fragment. All of the fusion proteins were highly expressed in E. coli and the CBM9-ID-H1 fusion protein was shown to yield 122 mg/L of purified product. Three purified CBM9-SARS-CoV-2 fusion proteins were tested and found to bind antibodies directed to the appropriate SARS-CoV-2 antigenic regions. The largest intact CBM9 fusion protein, CBM9-ID-H1, incorporates spike protein amino acids 540-588, which is a conserved region overlapping and C-terminal to the receptor binding domain that is widely recognized by human convalescent sera and contains a putative protective epitope.


Subject(s)
Coronavirus Nucleocapsid Proteins/genetics , Escherichia coli/metabolism , Recombinant Fusion Proteins/biosynthesis , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/genetics , Antibodies, Viral/immunology , Antigen-Antibody Reactions , COVID-19/pathology , COVID-19/virology , Chromatography, High Pressure Liquid , Coronavirus Nucleocapsid Proteins/metabolism , Humans , Mass Spectrometry , Phosphoproteins/genetics , Phosphoproteins/metabolism , Receptors, Cell Surface/genetics , Recombinant Fusion Proteins/analysis , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunology , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/metabolism
12.
Chembiochem ; 23(2): e202100514, 2022 01 19.
Article in English | MEDLINE | ID: covidwho-1653182

ABSTRACT

In addition to a membrane anchor, the transmembrane domain (TMD) of single-pass transmembrane proteins (SPTMPs) recently has shown essential roles in the cross-membrane activity or receptor assembly/clustering. However, these small TMD peptides are generally hydrophobic and dynamic, difficult to be expressed and purified. Here, we have integrated the power of TrpLE fusion protein and a sequence-specific nickel-assisted cleavage (SNAC)-tag to produce small TMD peptides in a highly efficient way under mild conditions, which uses Ni2+ as the cleavage reagent, avoiding the usage of toxic cyanogen bromide (CNBr). Furthermore, this method simplifies the downstream protein purification and reconstitution. Two representative TMDs, including the Spike-TMD from severe acute respiratory syndrome coronavirus 2 (SARS2), were successfully produced with high-quality nuclear magnetic resonance (NMR) spectra. Therefore, our study provides a more efficient and practical approach for general structural characterization of the small TM proteins.


Subject(s)
Nickel/chemistry , Peptides/metabolism , Recombinant Fusion Proteins/metabolism , COVID-19/pathology , COVID-19/virology , Catalysis , Humans , Membrane Proteins/chemistry , Membrane Proteins/genetics , Membrane Proteins/metabolism , Nuclear Magnetic Resonance, Biomolecular , Peptides/chemistry , Peptides/isolation & purification , Proteolysis , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/isolation & purification , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism
13.
MAbs ; 14(1): 2021601, 2022.
Article in English | MEDLINE | ID: covidwho-1625321

ABSTRACT

Coronavirus disease 2019, caused by SARS-CoV-2, remains an on-going pandemic, partly due to the emergence of variant viruses that can "break-through" the protection of the current vaccines and neutralizing antibodies (nAbs), highlighting the needs for broadly nAbs and next-generation vaccines. We report an antibody that exhibits breadth and potency in binding the receptor-binding domain (RBD) of the virus spike glycoprotein across SARS coronaviruses. Initially, a lead antibody was computationally discovered and crystallographically validated that binds to a highly conserved surface of the RBD of wild-type SARS-CoV-2. Subsequently, through experimental affinity enhancement and computational affinity maturation, it was further developed to bind the RBD of all concerning SARS-CoV-2 variants, SARS-CoV-1 and pangolin coronavirus with pico-molar binding affinities, consistently exhibited strong neutralization activity against wild-type SARS-CoV-2 and the Alpha and Delta variants. These results identify a vulnerable target site on coronaviruses for development of pan-sarbecovirus nAbs and vaccines.


Subject(s)
Antibodies, Viral/immunology , Antigens, Viral/immunology , Broadly Neutralizing Antibodies/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Viral/genetics , Antibodies, Viral/metabolism , Antibody Affinity , Antibody Specificity , Antigen-Antibody Reactions , Antigens, Viral/chemistry , Antigens, Viral/genetics , Broadly Neutralizing Antibodies/genetics , Broadly Neutralizing Antibodies/metabolism , Crystallography, X-Ray , Epitopes/chemistry , Epitopes/immunology , Humans , Immunoglobulin Fragments/immunology , Molecular Docking Simulation , Monte Carlo Method , Neutralization Tests , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Protein Domains , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunology , Recombinant Fusion Proteins/metabolism , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics
14.
PLoS Pathog ; 17(12): e1010175, 2021 12.
Article in English | MEDLINE | ID: covidwho-1592244

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the COVID-19 pandemic. Currently, as dangerous mutations emerge, there is an increased demand for specific treatments for SARS-CoV-2 infected patients. The spike glycoprotein on the virus envelope binds to the angiotensin converting enzyme 2 (ACE2) on host cells through its receptor binding domain (RBD) to mediate virus entry. Thus, blocking this interaction may inhibit viral entry and consequently stop infection. Here, we generated fusion proteins composed of the extracellular portions of ACE2 and RBD fused to the Fc portion of human IgG1 (ACE2-Ig and RBD-Ig, respectively). We demonstrate that ACE2-Ig is enzymatically active and that it can be recognized by the SARS-CoV-2 RBD, independently of its enzymatic activity. We further show that RBD-Ig efficiently inhibits in-vivo SARS-CoV-2 infection better than ACE2-Ig. Mechanistically, we show that anti-spike antibody generation, ACE2 enzymatic activity, and ACE2 surface expression were not affected by RBD-Ig. Finally, we show that RBD-Ig is more efficient than ACE2-Ig at neutralizing high virus titers. We thus propose that RBD-Ig physically blocks virus infection by binding to ACE2 and that RBD-Ig should be used for the treatment of SARS-CoV-2-infected patients.


Subject(s)
Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Immunoglobulin Fc Fragments/metabolism , Immunoglobulin G/metabolism , Protein Domains , Recombinant Fusion Proteins/metabolism , SARS-CoV-2/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Animals , Binding Sites , Binding Sites, Antibody , COVID-19/prevention & control , Chlorocebus aethiops , Female , HEK293 Cells , Humans , Immunoglobulin Fc Fragments/therapeutic use , Immunoglobulin G/therapeutic use , Mice, Transgenic , Neutralization Tests , Protein Binding , Recombinant Fusion Proteins/therapeutic use , SARS-CoV-2/drug effects , Vero Cells
15.
Medicine (Baltimore) ; 100(50): e28236, 2021 Dec 17.
Article in English | MEDLINE | ID: covidwho-1583957

ABSTRACT

RATIONALE: In this paper, we report on 2 patients who developed branch retinal vein occlusion (BRVO) exacerbation 1 day after administration of the BNT162b2 (Pfizer-BioNTech) SARS-CoV-2 vaccine. PATIENT CONCERNS: Case 1: A 71 year-old female developed vision loss in her left eye 1 day after receiving a second dose of the SARS-CoV-2 mRNA vaccine. This patient was diagnosed with temporal inferior BRVO and secondary macular edema (ME) in her left eye. ME resolved after 3 doses of intravitreal aflibercept (IVA). After treatment, no recurrence of ME was observed.Case 2: A 72 year-old man developed vision loss in his right eye 1 day after receiving the first dose of the SARS-CoV-2 mRNA vaccine. This patient was diagnosed with temporal superior BRVO in the right eye without ME. The patient was followed up and did not undergo any additional treatment. DIAGNOSES: Case1: Temporal superior BRVO and secondary ME were observed in the left eye. Her best-corrected visual acuity (BCVA) was 20/30.Case2: Temporal superior BRVO recurrence and secondary ME were observed in the right eye. BCVA was 20/25. INTERVENTIONS: Case1: Additional dose of IVA was administered. Case2: Two times of Intravitreal ranibizumab was administered twice. OUTCOMES: Case1: Subsequently, ME resolved BCVA was 20/20. Case2: Subsequently, ME resolved BCVA was 20/25. LESSONS: Both cases showed a possible association between SARS-CoV-2 vaccination and the exacerbation of BRVO.


Subject(s)
/adverse effects , COVID-19 , Macular Edema , Retinal Vein Occlusion/chemically induced , Aged , Angiogenesis Inhibitors/therapeutic use , COVID-19/prevention & control , Female , Humans , Intravitreal Injections , Macular Edema/drug therapy , Male , Ranibizumab/therapeutic use , Receptors, Vascular Endothelial Growth Factor/therapeutic use , Recombinant Fusion Proteins/therapeutic use , Retinal Vein Occlusion/drug therapy , Treatment Outcome , Vaccination , Visual Acuity
16.
Infect Genet Evol ; 97: 105188, 2022 01.
Article in English | MEDLINE | ID: covidwho-1568934

ABSTRACT

The best and most effective way to combat pandemics is to use effective vaccines and live attenuated vaccines are among the most effective vaccines. However, one of the major problems is the length of time it takes to get the attenuated vaccines. Today, the CRISPR toolkit (Clustered Regularly Inerspaced Short Palindromic Repeats) has made it possible to make changes with high efficiency and speed. Using this toolkit to make point mutations on the RNA virus's genome in a coculture of permissive and nonpermissive cells and under controlled conditions can accelerate changes in the genome and accelerate natural selection to obtain live attenuated vaccines.


Subject(s)
COVID-19 Vaccines/genetics , COVID-19/prevention & control , CRISPR-Cas Systems , Gene Editing/methods , Mutation Rate , SARS-CoV-2/genetics , Viral Proteins/genetics , APOBEC Deaminases/genetics , APOBEC Deaminases/immunology , Adenosine Deaminase/genetics , Adenosine Deaminase/immunology , Bacterial Proteins/genetics , Bacterial Proteins/immunology , COVID-19/immunology , COVID-19 Vaccines/biosynthesis , Endonucleases/genetics , Endonucleases/immunology , Gene Expression , Genome, Viral , Humans , RNA-Binding Proteins/genetics , RNA-Binding Proteins/immunology , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunology , SARS-CoV-2/immunology , Selection, Genetic , Vaccines, Attenuated , Viral Proteins/immunology
17.
Nat Med ; 27(7): 1262-1271, 2021 07.
Article in English | MEDLINE | ID: covidwho-1550325

ABSTRACT

Preclinical and clinical data suggest that fibroblast growth factor 21 (FGF21) is anti-fibrotic, improves metabolic status and has potential to treat non-alcoholic steatohepatitis (NASH). We assessed the safety and efficacy of efruxifermin, a long-acting Fc-FGF21 fusion protein, for the treatment of NASH. BALANCED was a randomized, placebo-controlled study in patients with NASH conducted at 27 centers in the United States (ClinicalTrials.gov NCT03976401 ). Eighty patients, stratified by hepatic fat fraction (HFF) and fibrosis stage, were randomized using a centrally administered minimization algorithm 1:1:1:1 to receive placebo (n = 21) or efruxifermin 28 mg (n = 19), efruxifermin 50 mg (n = 20) or efruxifermin 70 mg (n = 20) via weekly subcutaneous injection for 16 weeks. The primary endpoint-absolute change from baseline in HFF measured as magnetic resonance imaging-proton density fat fraction at week 12-was met. For the full analysis set, the least squares mean absolute changes (one-sided 97.5% confidence interval) from baseline in HFF were -12.3% (-infinity (-inf), -10.3), -13.4% (-inf, -11.4) and -14.1% (-inf, -12.1) in the 28-, 50- and 70-mg groups, respectively, versus 0.3% (-inf, 1.6) in the placebo group, with statistically significant differences between efruxifermin groups and placebo (P < 0.0001 each). Overall, 70 of 79 patients who received the study drug (89%) experienced at least one treatment-emergent adverse event (TEAE), with the majority grade 1-2 (64 (81%)), five (6%) grade 3 and one grade 4. The most commonly reported drug-related TEAEs were grade 1-2 gastrointestinal (36 (46%)). Treatment with efruxifermin significantly reduced HFF in patients with F1-F3 stage NASH, with an acceptable safety profile.


Subject(s)
Fibroblast Growth Factors/therapeutic use , Immunoglobulin Fc Fragments/therapeutic use , Non-alcoholic Fatty Liver Disease/drug therapy , Recombinant Fusion Proteins/therapeutic use , Body Mass Index , Double-Blind Method , Female , Humans , Liver/pathology , Liver Cirrhosis/drug therapy , Magnetic Resonance Imaging , Male , Middle Aged , Treatment Outcome
18.
Chembiochem ; 23(2): e202100514, 2022 01 19.
Article in English | MEDLINE | ID: covidwho-1549172

ABSTRACT

In addition to a membrane anchor, the transmembrane domain (TMD) of single-pass transmembrane proteins (SPTMPs) recently has shown essential roles in the cross-membrane activity or receptor assembly/clustering. However, these small TMD peptides are generally hydrophobic and dynamic, difficult to be expressed and purified. Here, we have integrated the power of TrpLE fusion protein and a sequence-specific nickel-assisted cleavage (SNAC)-tag to produce small TMD peptides in a highly efficient way under mild conditions, which uses Ni2+ as the cleavage reagent, avoiding the usage of toxic cyanogen bromide (CNBr). Furthermore, this method simplifies the downstream protein purification and reconstitution. Two representative TMDs, including the Spike-TMD from severe acute respiratory syndrome coronavirus 2 (SARS2), were successfully produced with high-quality nuclear magnetic resonance (NMR) spectra. Therefore, our study provides a more efficient and practical approach for general structural characterization of the small TM proteins.


Subject(s)
Nickel/chemistry , Peptides/metabolism , Recombinant Fusion Proteins/metabolism , COVID-19/pathology , COVID-19/virology , Catalysis , Humans , Membrane Proteins/chemistry , Membrane Proteins/genetics , Membrane Proteins/metabolism , Nuclear Magnetic Resonance, Biomolecular , Peptides/chemistry , Peptides/isolation & purification , Proteolysis , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/isolation & purification , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism
19.
Vaccine ; 39(45): 6601-6613, 2021 10 29.
Article in English | MEDLINE | ID: covidwho-1541007

ABSTRACT

AKS-452 is a biologically-engineered vaccine comprising an Fc fusion protein of the SARS-CoV-2 viral spike protein receptor binding domain antigen (Ag) and human IgG1 Fc (SP/RBD-Fc) in clinical development for the induction and augmentation of neutralizing IgG titers against SARS-CoV-2 viral infection to address the COVID-19 pandemic. The Fc moiety is designed to enhance immunogenicity by increasing uptake via Fc-receptors (FcγR) on Ag-presenting cells (APCs) and prolonging exposure due to neonatal Fc receptor (FcRn) recycling. AKS-452 induced approximately 20-fold greater neutralizing IgG titers in mice relative to those induced by SP/RBD without the Fc moiety and induced comparable long-term neutralizing titers with a single dose vs. two doses. To further enhance immunogenicity, AKS-452 was evaluated in formulations containing a panel of adjuvants in which the water-in-oil adjuvant, Montanide™ ISA 720, enhanced neutralizing IgG titers by approximately 7-fold after one and two doses in mice, including the neutralization of live SARS-CoV-2 virus infection of VERO-E6 cells. Furthermore, ISA 720-adjuvanted AKS-452 was immunogenic in rabbits and non-human primates (NHPs) and protected from infection and clinical symptoms with live SARS-CoV-2 virus in NHPs (USA-WA1/2020 viral strain) and the K18 human ACE2-trangenic (K18-huACE2-Tg) mouse (South African B.1.351 viral variant). These preclinical studies support the initiation of Phase I clinical studies with adjuvanted AKS-452 with the expectation that this room-temperature stable, Fc-fusion subunit vaccine can be rapidly and inexpensively manufactured to provide billions of doses per year especially in regions where the cold-chain is difficult to maintain.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19 , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , Immunoglobulin G , Mice , Primates , Rabbits , Recombinant Fusion Proteins/immunology , SARS-CoV-2 , Vaccines, Subunit
20.
Biochem Biophys Res Commun ; 586: 137-142, 2022 01 01.
Article in English | MEDLINE | ID: covidwho-1520712

ABSTRACT

Nuclear pore complexes (NPC) regulate molecular traffics on nuclear envelope, which plays crucial roles during cell fate specification and diseases. The viral accessory protein NSP9 of SARS-CoV-2 is reported to interact with nucleoporin 62 (NUP62), a structural component of the NPC, but its biological impact on the host cell remain obscure. Here, we established new cell line models with ectopic NSP9 expression and determined the subcellular destination and biological functions of NSP9. Confocal imaging identified NSP9 to be largely localized in close proximity to the endoplasmic reticulum. In agreement with the subcellular distribution of NSP9, association of NSP9 with NUP62 was observed in cytoplasm. Furthermore, the overexpression of NSP9 correlated with a reduction of NUP62 expression on the nuclear envelope, suggesting that attenuating NUP62 expression might have contributed to defective NPC formation. Importantly, the loss of NUP62 impaired translocation of p65, a subunit of NF-κB, upon TNF-α stimulation. Concordantly, NSP9 over-expression blocked p65 nuclear transport. Taken together, these data shed light on the molecular mechanisms underlying the modulation of host cells during SARS-CoV-2 infection.


Subject(s)
COVID-19/metabolism , COVID-19/virology , Host Microbial Interactions/physiology , Membrane Glycoproteins/metabolism , Nuclear Pore Complex Proteins/metabolism , RNA-Binding Proteins/metabolism , SARS-CoV-2/metabolism , Viral Nonstructural Proteins/metabolism , Active Transport, Cell Nucleus , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum/virology , Gene Knockdown Techniques , HeLa Cells , Humans , Membrane Glycoproteins/antagonists & inhibitors , Membrane Glycoproteins/genetics , Models, Biological , Nuclear Envelope/metabolism , Nuclear Envelope/virology , Nuclear Pore Complex Proteins/antagonists & inhibitors , Nuclear Pore Complex Proteins/genetics , RNA-Binding Proteins/genetics , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Transcription Factor RelA/metabolism , Viral Nonstructural Proteins/genetics
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