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1.
Nat Immunol ; 11(10): 905-11, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20802483

RESUMO

Interleukin 1ß (IL-1ß) is a key orchestrator of inflammation and host defense that exerts its effects through IL-1 receptor type I (IL-1RI) and IL-1 receptor accessory protein (IL-1RAcP). How IL-1RAcP is recruited by IL-1ß-IL-1RI to form the signaling-competent complex remains elusive. Here we present the crystal structure of IL-1ß bound to IL-1 receptor type II (IL-1RII) and IL-1RAcP. IL-1ß-IL-1RII generated a composite binding surface to recruit IL-1RAcP. Biochemical analysis demonstrated that IL-1ß-IL-1RI and IL-1ß-IL-1RII interacted similarly with IL-1RAcP. It also showed the importance of two loops of IL-1 receptor antagonist (IL-1Ra) in determining its antagonism. Our results provide a structural basis for assembly and activation of the IL-1 receptor and offer a general cytokine-receptor architecture that governs the IL-1 family of cytokines.


Assuntos
Proteína Acessória do Receptor de Interleucina-1/química , Interleucina-1beta/química , Receptores Tipo II de Interleucina-1/química , Sequência de Aminoácidos , Cristalografia , Humanos , Proteína Antagonista do Receptor de Interleucina 1/química , Proteína Acessória do Receptor de Interleucina-1/metabolismo , Interleucina-1beta/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Receptores Tipo II de Interleucina-1/metabolismo , Alinhamento de Sequência , Transdução de Sinais
2.
Genes Dev ; 27(12): 1339-44, 2013 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-23756652

RESUMO

The R-spondin (RSPO) family of secreted proteins (RSPO1-RSPO4) has pleiotropic functions in development and stem cell growth by strongly enhancing Wnt pathway activation. Recently, leucine-rich repeat-containing G-protein-coupled receptor 4 (LGR4), LGR5, and LGR6 have been identified as receptors for RSPOs. Here we report the complex structure of the LGR4 extracellular domain (ECD) with the RSPO1 N-terminal fragment (RSPO1-2F) containing two adjacent furin-like cysteine-rich domains (FU-CRDs). The LGR4-ECD adopts the anticipated TLR horseshoe structure and uses its concave surface close to the N termini to bind RSPO1-2F. Both the FU-CRD1 and FU-CRD2 domains of RSPO1 contribute to LGR4 interaction, and binding and cellular assays identified critical RSPO1 residues for its biological activities. Our results define the molecular mechanism by which the LGR4/5/6 receptors recognize RSPOs and also provide structural insights into the signaling difference between the LGR4/5/6 receptors and other members in the LGR family.


Assuntos
Modelos Moleculares , Trombospondinas/química , Trombospondinas/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular , Humanos , Dados de Sequência Molecular , Mutação , Ligação Proteica , Estrutura Terciária de Proteína , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Alinhamento de Sequência , Transdução de Sinais , Trombospondinas/genética
3.
J Biol Chem ; 294(12): 4290-4303, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-30737282

RESUMO

Most neutralizing antibodies against highly pathogenic avian influenza A virus H5N1 recognize the receptor-binding site (RBS) on the globular head domain and the stem of H5N1 hemagglutinin (HA). Through comprehensive analysis of multiple human protective antibodies, we previously identified four vulnerable sites (VS1-VS4) on the globular head domain. Among them, the VS1, occupying the opposite side of the RBS on the same HA, was defined by the epitope of antibody 65C6. In this study, we report the crystal structures of two additional human H5N1 antibodies isolated from H5N1-infected individuals, 3C11 and AVFluIgG01, bound to the head at 2.33- and 2.30-Å resolution, respectively. These two new antibody epitopes have large overlap with and extend beyond the original VS1. Site-directed mutagenesis experiments identified eight pivotal residues (Ser-126b, Lys-165, Arg-166, Ser-167, Tyr-168, Asn-169, Thr-171, and Asn-172) critical for 65C6-, 3C11-, and AVFluIgG01-binding and neutralization activities. These residues formed a unique "Y"-shaped surface on H5N1 globular head and are highly conserved among H5N1 viruses. Our results further support the existence of a vulnerable site distinct from the RBS and the stem region of H5N1 HA, and future design of immunogens should take this particular site into consideration.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Virus da Influenza A Subtipo H5N1/metabolismo , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Sítios de Ligação , Cristalografia por Raios X , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Virus da Influenza A Subtipo H5N1/imunologia , Virus da Influenza A Subtipo H5N1/patogenicidade , Mutagênese Sítio-Dirigida , Conformação Proteica , Reprodutibilidade dos Testes
4.
J Infect Dis ; 218(8): 1249-1260, 2018 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-29846635

RESUMO

Background: The Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory infection with a high (~35%) mortality rate. Neutralizing antibodies targeting the spike of MERS-CoV have been shown to be a therapeutic option for treatment of lethal disease. Methods: We describe the germline diversity and neutralizing activity of 13 potent human monoclonal antibodies (mAbs) that target the MERS-CoV spike (S) protein. Biological functions were assessed by live MERS-CoV, pseudotype particle and its variants, and structural basis was also determined by crystallographic analysis. Results: Of the 13 mAbs displaying strong neutralizing activity against MERS-CoV, two with the immunoglobulin heavy-chain variable region (IGHV)1-69-derived heavy chain (named MERS-GD27 and MERS-GD33) showed the most potent neutralizing activity against pseudotyped and live MERS-CoV in vitro. Mutagenesis analysis suggested that MERS-GD27 and MERS-GD33 recognized distinct regions in S glycoproteins, and the combination of 2 mAbs demonstrated a synergistic effect in neutralization against pseudotyped MERS-CoV. The structural basis of MERS-GD27 neutralization and recognition revealed that its epitope almost completely overlapped with the receptor-binding site. Conclusions: Our data provide new insights into the specific antibody repertoires and the molecular determinants of neutralization during natural MERS-CoV infection in humans. This finding supports additional efforts to design and develop novel therapies to combat MERS-CoV infections in humans.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Anticorpos Monoclonais/imunologia , Especificidade de Anticorpos , Ensaio de Imunoadsorção Enzimática , Mapeamento de Epitopos , Humanos , Masculino , Modelos Moleculares , Conformação Proteica
5.
J Immunol ; 189(1): 245-52, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22664871

RESUMO

Receptor activator of NF-κB ligand (RANKL), its signaling receptor RANK, and its decoy receptor osteoprotegerin (OPG) constitute a molecular triad that is critical in regulating bone remodeling, and also plays multiple roles in the immune system. OPG binds RANKL directly to block its interaction with RANK. In this article, we report the 2.7-Å crystal structure of human RANKL trimer in complex with the N-terminal fragment of human OPG containing four cysteine-rich TNFR homologous domains (OPG-CRD). The structure shows that RANKL trimer uses three equivalent grooves between two neighboring monomers to interact with three OPG-CRD monomers symmetrically. A loop from the CRD3 domain of OPG-CRD inserts into the shallow groove of RANKL, providing the major binding determinant that is further confirmed by affinity measurement and osteoclast differentiation assay. These results, together with a previously reported mouse RANKL/RANK complex structure, reveal that OPG exerts its decoy receptor function by directly blocking the accessibilities of important interacting residues of RANKL for RANK recognition. Structural comparison with TRAIL/death receptor 5 complex also reveals structural basis for the cross-reactivity of OPG to TRAIL.


Assuntos
Osteoprotegerina/química , Osteoprotegerina/fisiologia , Ligante RANK/química , Ligante RANK/fisiologia , Animais , Cristalografia por Raios X , Cisteína/química , Cisteína/metabolismo , Humanos , Camundongos , Mutagênese Sítio-Dirigida , Osteoprotegerina/genética , Ligação Proteica/imunologia , Multimerização Proteica , Estrutura Terciária de Proteína , Ligante RANK/genética
6.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 38(7): 874-879, 2024 Jul 15.
Artigo em Zh | MEDLINE | ID: mdl-39013827

RESUMO

Objective: To investigate the short-term effectiveness of unilateral biportal endoscopy (UBE) in treatment of lumbar lateral saphenous fossa combined with intervertebral foramina stenosis via contralateral sublaminar approach. Methods: A clinical data of 15 patients with lumbar lateral saphenous fossa combined with intervertebral foramina stenosis, who were admitted between September 2021 and December 2023 and met selective criteria, was retrospectively analyzed. There were 5 males and 10 females with an average age of 70.3 years (range, 46-83 years). Surgical segment was L 4, 5 in 12 cases and L 5, S 1 in 3 cases. The disease duration was 12-30 months (mean, 18.7 months). All patients were treated by UBE via contralateral sublaminar approach. The operation time, intraoperative blood loss, postoperative hospital stay, and the occurrence of complications were recorded. The visual analogue scale (VAS) score was used to evaluate the degree of lower back and leg pain before and after operation; the Japanese Orthopaedic Association (JOA) score and the Oswestry disability index (ODI) were used to evaluate the lumbar function; and the clinical outcome was evaluated using the MacNab criteria at 6 months after operation. Postoperative MRI and CT were taken to observe whether the lateral saphenous fossa and intervertebral foramen stenosis were removed or not, and the cross-sectional area of the spinal canal (CSA-SC), cross-sectional area of the intervertebral foramen (CSA-IVF), and cross-sectional area of the facet joint (CSA-FJ) were measured. Results: The operation time was 55-200 minutes (mean, 127.5 minutes); the intraoperative blood loss was 10-50 mL (mean, 27.3 mL); the length of postoperative hospital stay was 3-12 days (mean, 6.8 days). All patients were followed up 6-12 months (mean, 8.9 months). At 1 day, 1 month, 3 months, and 6 months after operation, the VAS scores of low back and leg pain and ODI scores after operation were significantly lower than preoperative scores and showed a gradual decrease with time; the JOA scores showed a gradual increase with time; the differences in the above indexes between different time points were significant ( P<0.05). The clinical outcome was rated as excellent in 10 cases, good in 4 cases, and poor in 1 case according to the MacNab criteria at 6 months after operation, with an excellent and good rate of 93.33%. Imaging review showed that the compression on the lateral saphenous fossa and intervertebral foramina had been significantly relieved, and the affected articular process joint was preserved to the maximum extent; the CSA-SC and CSA-IVF at 3 days after operation significantly increased compared to the preoperative values ( P<0.05), and the CSA-FJ significantly reduced ( P<0.05). Conclusion: The UBE via contralateral sublaminar approach can effectively reduce pressure in the lateral saphenous fossa and the intervertebral foramina of the same segment while preserving the bilateral articular process joints. The short-term effectiveness is good and it is expected to avoid fusion surgery caused by iatrogenic instability of the lumbar spine. However, further follow-up is needed to clarify the mid- and long-term effectiveness.


Assuntos
Endoscopia , Vértebras Lombares , Estenose Espinal , Humanos , Masculino , Feminino , Estenose Espinal/cirurgia , Pessoa de Meia-Idade , Idoso , Vértebras Lombares/cirurgia , Endoscopia/métodos , Resultado do Tratamento , Idoso de 80 Anos ou mais , Descompressão Cirúrgica/métodos , Medição da Dor , Dor Lombar/etiologia , Dor Lombar/cirurgia
7.
J Biol Chem ; 287(51): 43170-9, 2012 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-23100255

RESUMO

VRC01, a broadly neutralizing monoclonal antibody, is capable of neutralizing a diverse array of HIV-1 isolates by mimicking CD4 binding with the envelope glycoprotein gp120. Nonetheless, resistant strains have been identified. Here, we examined two genetically related and two unrelated envelope clones, derived from CRF08_BC-infected patients, with distinct VRC01 neutralization profiles. A total of 22 chimeric envelope clones was generated by interchanging the loop D and/or V5 regions between the original envelopes or by single alanine substitutions within each region. Analysis of pseudoviruses built from these mutant envelopes showed that interchanging the V5 region between the genetically related or unrelated clones completely swapped their VRC01 sensitivity profiles. Mutagenesis analysis revealed that the asparagine residue at position 460 (Asn-460), a potential N-linked glycosylation site in the V5 region, is a key factor for observed resistance in these strains, which is further supported by our structural modeling. Moreover, changes in resistance were found to positively correlate with deviations in VRC01 binding affinity. Overall, our study indicates that Asn-460 in the V5 region is a critical determinant of sensitivity to VRC01 specifically in these viral strains. The long side chain of Asn-460, and potential glycosylation, may create steric hindrance that lowers binding affinity, thereby increasing resistance to VRC01 neutralization.


Assuntos
Aminoácidos/metabolismo , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Sequência de Aminoácidos , Anticorpos Monoclonais/farmacologia , Asparagina/metabolismo , Antígenos CD4/metabolismo , Genótipo , Proteína gp160 do Envelope de HIV/química , Proteína gp160 do Envelope de HIV/imunologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Modelos Moleculares , Dados de Sequência Molecular , Mutação/genética , Fenótipo , Ligação Proteica/efeitos dos fármacos , Estrutura Secundária de Proteína , Solubilidade , Relação Estrutura-Atividade
8.
Immunol Invest ; 42(2): 106-21, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23252862

RESUMO

Broadly neutralizing antibodies and appropriate immunogens are critical for preexposure prophylaxis and therapeutic HIV vaccines. In this study, we aimed to explore effective antibodies against the genetically diverse HIV-1 strains by investigating the roles of human CD4 D1D2 domain and nonvariable immugens. The human CD4 D1D2 domain and the chimeric protein of mouse D1 domain/human D2 domain were expressed in Sf9 insect cells and purified by gel-filtration chromatography. The human CD4 D1D2 domain potently inhibited the infection of 77.8% HIV-1 pseudoviruses, including the clades AE, B' and BC, with less than 20 µg/mL of IC(50). pcDNA3.1-mhD1D2m and pcDNA3.1-mhD2m plasmids were used for the production of mouse anti-human CD4 polyclonal antibodies. The neutralizing activities of the polyclonal antibodies were determined by using pseudotyped HIV-1 viruses. The antibodies induced by plasmids containing human CD4 D1D2 domain were able to potently inhibit all pseudotyped HIV-1 strains. The antibodies from mhD1D2m-immunized mice also showed strong binding capacity to CD4 expressed on the surface of TZM-bl cells. The potent and broad inhibitory activity of antibodies against the human CD4 D1D2 domain may be used to develop effective passive immunization agent to control the spread of HIV infection.


Assuntos
Antígenos CD4/química , Antígenos CD4/imunologia , Anticorpos Anti-HIV/biossíntese , Infecções por HIV/prevenção & controle , HIV-1/imunologia , Vacinas contra a AIDS/química , Vacinas contra a AIDS/genética , Vacinas contra a AIDS/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Neutralizantes/biossíntese , Anticorpos Neutralizantes/imunologia , Antígenos CD4/genética , Antígenos CD4/metabolismo , Linhagem Celular , Células Cultivadas , Feminino , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Humanos , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Testes de Neutralização , Estrutura Terciária de Proteína , Spodoptera
9.
J Biol Chem ; 286(35): 30258-30262, 2011 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-21757684

RESUMO

ISG15 (interferon-stimulated gene 15), the first ubiquitin-like protein (UBL) identified, has emerged as an important cellular antiviral factor. It consists of two UBL domains with a short linker between them. The covalent attachment of ISG15 to host and viral proteins to modify their functions, similar to ubiquitylation, is named ISGylation. Influenza B virus NS1B protein antagonizes human but not mouse ISGylation because NS1B exhibits species specificity; it only binds human and non-human primate ISG15. Previous studies have demonstrated that the N-terminal UBL domain and linker of ISG15 are required for the binding by NS1B and that the linker plays a large role in the species specificity, but the structural basis for them has not been elucidated. Here we report the crystal structure of human ISG15 in complex with NS1B at a resolution of 2.0 Å. A loop in the ISG15 N-terminal UBL domain inserts into a pocket in the NS1B dimer, forming a high affinity binding site. The nonspecific van der Waals contacts around the ISG15 linker form a low affinity site for NS1B binding. However, sequence alignment reveals that residues in the high affinity site are highly conserved in primate and non-primate ISG15. We propose that the low affinity binding around the ISG15 linker is important for the initial contact with NS1B and that the stable complex formation is largely contributed by the following high affinity interactions between ISG15 N-terminal UBL domain and NS1B. This provides a structural basis for the species-specific binding of ISG15 by the NS1B protein.


Assuntos
Citocinas/química , Vírus da Influenza B/metabolismo , Ubiquitinas/química , Proteínas não Estruturais Virais/química , Animais , Sítios de Ligação , Cromatografia em Gel , Cristalografia por Raios X/métodos , Dimerização , Escherichia coli/metabolismo , Humanos , Camundongos , Conformação Molecular , Mutação , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas não Estruturais Virais/metabolismo
10.
Int J Biol Macromol ; 205: 316-328, 2022 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-35192905

RESUMO

Conserved and multifunctional Geminivirus Replication-associated Protein (Rep) specifically recognizes the replication origin and initiates viral DNA replication. We report the X-ray crystallography-based structures of two complexes containing the N-terminal domain (5-117aa) of Tomato yellow leaf curl virus (TYLCV) Rep: the catalytically-dead Rep in complex with nonanucleotide ssDNA (Rep5-117 Y101F-ssDNA) as well as the catalytically-active phosphotyrosine covalent adduct (Rep5-117-ssDNA). These structures provide functional insight into the role of Rep in viral replication. Metal ions stabilize the DNA conformation by interacting with the phosphate group of adenine and thus promote formation of the catalytic center. Furthermore, we identified a compound that inhibits the binding of Rep to ssDNA and dsDNA and found that the addition of metal ions compromises the inhibitory effectiveness of this compound. This study demonstrates the mechanism of DNA recognition and cleavage process of viral Rep, emphasizing the role of metal ions.


Assuntos
Begomovirus , Solanum lycopersicum , Begomovirus/genética , Begomovirus/metabolismo , Replicação do DNA , DNA Viral/genética , DNA Viral/metabolismo , Solanum lycopersicum/genética , Replicação Viral/genética
11.
Nat Commun ; 13(1): 7957, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36575191

RESUMO

As SARS-CoV-2 Omicron and other variants of concern (VOCs) continue spreading worldwide, development of antibodies and vaccines to confer broad and protective activity is a global priority. Here, we report on the identification of a special group of nanobodies from immunized alpaca with potency against diverse VOCs including Omicron subvariants BA.1, BA.2 and BA.4/5, SARS-CoV-1, and major sarbecoviruses. Crystal structure analysis of one representative nanobody, 3-2A2-4, discovers a highly conserved epitope located between the cryptic and the outer face of the receptor binding domain (RBD), distinctive from the receptor ACE2 binding site. Cryo-EM and biochemical evaluation reveal that 3-2A2-4 interferes structural alteration of RBD required for ACE2 binding. Passive delivery of 3-2A2-4 protects K18-hACE2 mice from infection of authentic SARS-CoV-2 Delta and Omicron. Identification of these unique nanobodies will inform the development of next generation antibody therapies and design of pan-sarbecovirus vaccines.


Assuntos
COVID-19 , Camelídeos Americanos , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , Anticorpos de Domínio Único , Animais , Camundongos , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2 , COVID-19/prevenção & controle , Anticorpos Neutralizantes , Glicoproteína da Espícula de Coronavírus , Anticorpos Antivirais
12.
Curr Opin HIV AIDS ; 16(1): 74-81, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33186231

RESUMO

PURPOSE OF REVIEW: The spike glycoprotein plays a critical role in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by recognizing the angiotensin converting enzyme 2 (ACE2) receptor and mediating fusion of the viral envelope with the cell membrane. It is also the major target for neutralizing antibodies and vaccines. This review summarizes recent studies on the structure and function of spike glycoprotein, which revealed the structural basis of SARS-CoV-2 infection. RECENT FINDINGS: SARS-CoV-2 spike glycoprotein, similar to those of SARS-CoV and Middle East respiratory syndrome coronavirus, spontaneously samples different prefusion states with the receptor-binding domain (RBD) adopting 'up' or 'down' conformations, and the RBD 'down' to 'up' conformational change is required for ACE2 binding. Receptor binding and spike glycoprotein priming by host proteases such as furin and transmembrane protease serine 2 induce pre to postfusion conformational changes of the spike trimer that enable membrane fusion. Interactions between SARS-CoV-2 RBD and ACE2 were elucidated at atomic resolution using high-resolution crystal structures. These structures, together with adapted and remodeled SARS-CoV-2 strains, further revealed critical residues of the spike glycoprotein for SARS-CoV-2 infection and cross-species transmission. SUMMARY: Recent studies on SARS-CoV-2 spike glycoprotein provide important structural knowledge for a better understanding of the molecular mechanisms of SARS-CoV-2 infection and cross-species transmission.


Assuntos
COVID-19/virologia , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Enzima de Conversão de Angiotensina 2/química , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Sítios de Ligação , COVID-19/enzimologia , COVID-19/genética , Humanos , Ligação Proteica , SARS-CoV-2/química , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo
13.
Nat Commun ; 12(1): 250, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431856

RESUMO

Understanding the mechanism for antibody neutralization of SARS-CoV-2 is critical for the development of effective therapeutics and vaccines. We recently isolated a large number of monoclonal antibodies from SARS-CoV-2 infected individuals. Here we select the top three most potent yet variable neutralizing antibodies for in-depth structural and functional analyses. Crystal structural comparisons reveal differences in the angles of approach to the receptor binding domain (RBD), the size of the buried surface areas, and the key binding residues on the RBD of the viral spike glycoprotein. One antibody, P2C-1F11, most closely mimics binding of receptor ACE2, displays the most potent neutralizing activity in vitro and conferred strong protection against SARS-CoV-2 infection in Ad5-hACE2-sensitized mice. It also occupies the largest binding surface and demonstrates the highest binding affinity to RBD. More interestingly, P2C-1F11 triggers rapid and extensive shedding of S1 from the cell-surface expressed spike glycoprotein, with only minimal such effect by the remaining two antibodies. These results offer a structural and functional basis for potent neutralization via disruption of the very first and critical steps for SARS-CoV-2 cell entry.


Assuntos
Enzima de Conversão de Angiotensina 2/química , Enzima de Conversão de Angiotensina 2/metabolismo , Anticorpos Monoclonais/química , Anticorpos Neutralizantes/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Antivirais/imunologia , Sítios de Ligação , COVID-19/virologia , Modelos Animais de Doenças , Epitopos , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Receptores Virais/imunologia , Receptores Virais/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Internalização do Vírus , Tratamento Farmacológico da COVID-19
14.
Nat Commun ; 12(1): 4210, 2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244522

RESUMO

Neutralizing antibodies (nAbs) to SARS-CoV-2 hold powerful potentials for clinical interventions against COVID-19 disease. However, their common genetic and biologic features remain elusive. Here we interrogate a total of 165 antibodies from eight COVID-19 patients, and find that potent nAbs from different patients have disproportionally high representation of IGHV3-53/3-66 usage, and therefore termed as public antibodies. Crystal structural comparison of these antibodies reveals they share similar angle of approach to RBD, overlap in buried surface and binding residues on RBD, and have substantial spatial clash with receptor angiotensin-converting enzyme-2 (ACE2) in binding to RBD. Site-directed mutagenesis confirms these common binding features although some minor differences are found. One representative antibody, P5A-3C8, demonstrates extraordinarily protective efficacy in a golden Syrian hamster model against SARS-CoV-2 infection. However, virus escape analysis identifies a single natural mutation in RBD, namely K417N found in B.1.351 variant from South Africa, abolished the neutralizing activity of these public antibodies. The discovery of public antibodies and shared escape mutation highlight the intricate relationship between antibody response and SARS-CoV-2, and provide critical reference for the development of antibody and vaccine strategies to overcome the antigenic variation of SARS-CoV-2.


Assuntos
Enzima de Conversão de Angiotensina 2/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Receptores Virais/imunologia , SARS-CoV-2/imunologia , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Sítios de Ligação/imunologia , COVID-19/imunologia , Cricetinae , Modelos Animais de Doenças , Epitopos/imunologia , Feminino , Humanos , Masculino , Testes de Neutralização , Receptores de Antígenos de Linfócitos B/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia
15.
Emerg Microbes Infect ; 8(1): 841-856, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31169078

RESUMO

The Middle East respiratory syndrome coronavirus (MERS-CoV) has spread through 27 countries and infected more than 2,200 people since its first outbreak in Saudi Arabia in 2012. The high fatality rate (35.4%) of this novel coronavirus and its persistent wide spread infectiousness in animal reservoirs have generated tremendous global public health concern. However, no licensed therapeutic agents or vaccines against MERS-CoV are currently available and only a limited few have entered clinical trials. Among all the potential targets of MERS-CoV, the spike glycoprotein (S) has been the most well-studied due to its critical role in mediating viral entry and in inducing a protective antibody response in infected individuals. The most notable studies include the recent discoveries of monoclonal antibodies and development of candidate vaccines against the S glycoprotein. Structural characterization of MERS-CoV S protein bound with these monoclonal antibodies has provided insights into the mechanisms of humoral immune responses against MERS-CoV infection. The current review aims to highlight these developments and discuss possible hurdles and strategies to translate these discoveries into ultimate medical interventions against MERS-CoV infection.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Coronavirus/prevenção & controle , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Vacinas Virais/imunologia , Animais , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Humanos , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Glicoproteína da Espícula de Coronavírus/administração & dosagem , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/genética
16.
Nat Commun ; 10(1): 3068, 2019 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296843

RESUMO

Most neutralizing antibodies against Middle East respiratory syndrome coronavirus (MERS-CoV) target the receptor-binding domain (RBD) of the spike glycoprotein and block its binding to the cellular receptor dipeptidyl peptidase 4 (DPP4). The epitopes and mechanisms of mAbs targeting non-RBD regions have not been well characterized yet. Here we report the monoclonal antibody 7D10 that binds to the N-terminal domain (NTD) of the spike glycoprotein and inhibits the cell entry of MERS-CoV with high potency. Structure determination and mutagenesis experiments reveal the epitope and critical residues on the NTD for 7D10 binding and neutralization. Further experiments indicate that the neutralization by 7D10 is not solely dependent on the inhibition of DPP4 binding, but also acts after viral cell attachment, inhibiting the pre-fusion to post-fusion conformational change of the spike. These properties give 7D10 a wide neutralization breadth and help explain its synergistic effects with several RBD-targeting antibodies.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções por Coronavirus/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/metabolismo , Anticorpos Neutralizantes/ultraestrutura , Anticorpos Antivirais/sangue , Anticorpos Antivirais/metabolismo , Anticorpos Antivirais/ultraestrutura , Linhagem Celular Tumoral , Chlorocebus aethiops , Infecções por Coronavirus/sangue , Infecções por Coronavirus/virologia , Cristalografia por Raios X , Dipeptidil Peptidase 4/metabolismo , Modelos Animais de Doenças , Mapeamento de Epitopos , Epitopos/imunologia , Feminino , Células HEK293 , Humanos , Camundongos , Coronavírus da Síndrome Respiratória do Oriente Médio/metabolismo , Testes de Neutralização , Ligação Proteica/imunologia , Domínios Proteicos/imunologia , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura , Glicoproteína da Espícula de Coronavírus/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/metabolismo , Glicoproteína da Espícula de Coronavírus/ultraestrutura , Células Vero , Internalização do Vírus
17.
Artigo em Inglês | MEDLINE | ID: mdl-29535974

RESUMO

The deep hydrophobic pocket of HIV-1 gp41 has been considered a drug target, but short-peptides targeting this site usually lack potent antiviral activity. By applying the M-T hook structure, we previously generated highly potent short-peptide fusion inhibitors that specifically targeted the pocket site, such as MT-SC22EK, HP23L, and LP-11. Here, the crystal structures of HP23L and LP-11 bound to the target mimic peptide N36 demonstrated the critical intrahelical and interhelical interactions, especially verifying that the hook-like conformation was finely adopted while the methionine residue was replaced by the oxidation-less prone residue leucine, and that addition of an extra glutamic acid significantly enhanced the binding and inhibitory activities. The structure of HP23L bound to N36 with two mutations (E49K and L57R) revealed the critical residues and motifs mediating drug resistance and provided new insights into the mechanism of action of inhibitors. Therefore, the present data help our understanding for the structure-activity relationship (SAR) of HIV-1 fusion inhibitors and facilitate the development of novel antiviral drugs.


Assuntos
Farmacorresistência Viral , Proteína gp41 do Envelope de HIV/química , Inibidores da Fusão de HIV/química , HIV-1 , Proteínas Virais de Fusão/química , Sequência de Aminoácidos , Substituição de Aminoácidos , Antivirais , Cristalografia por Raios X , Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Ácido Glutâmico , Células HEK293 , Proteína gp41 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/farmacologia , Inibidores da Fusão de HIV/farmacologia , HIV-1/química , HIV-1/genética , Humanos , Leucina , Modelos Moleculares , Mutação de Sentido Incorreto , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Peptídeos/química , Peptídeos/genética , Peptídeos/farmacologia , Conformação Proteica , Domínios Proteicos/genética , Domínios e Motivos de Interação entre Proteínas , Proteínas dos Retroviridae/genética , Proteínas dos Retroviridae/farmacologia , Relação Estrutura-Atividade , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/farmacologia
18.
Medchemcomm ; 9(7): 1226-1231, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30109011

RESUMO

AIDS has evolved from a fatal infectious disease to a manageable chronic disease under the treatment of anti-AIDS medications. HIV fusion inhibitors with high activity, low side effects and strong selectivity are promising drugs against HIV. Only one fusion inhibitor is currently approved, thereby highly active long-acting fusion inhibitors need to be developed for long-term AIDS treatment. Here, we synthesised MT-SC22EK (a small HIV fusion inhibitor) derivatives containing 1-2 staples to improve its stability. Antiviral activity studies showed that MT-SC22EK-2 with two staples exhibited potent inhibitory activity against HIV-1 standard strains and Chinese epidemic strains, and at the same time, MT-SC22EK-2 presented strong anti-T20 resistance. Surprisingly, MT-SC22EK-2 possessed excellent protease stability with a half-life of 3665 min. MT-SC22EK-2 is a potential HIV fusion inhibitor considered as a long-acting anti-HIV drug candidate.

19.
Cell Rep ; 24(2): 441-452, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29996104

RESUMO

The major mechanism of antibody-mediated neutralization of the Middle East respiratory syndrome coronavirus (MERS-CoV) involves competition with the cellular receptor dipeptidyl peptidase 4 (DPP4) for binding to the receptor-binding domain (RBD) of the spike (S) glycoprotein. Here, we report a unique epitope and unusual neutralizing mechanism of the isolated human antibody MERS-4. Structurally, MERS-4 approached the RBD from the outside of the RBD-DPP4 binding interface. Such binding resulted in the folding of the ß5-ß6 loop toward a shallow groove on the RBD interface critical for accommodating DPP4. The key residues for binding are identified through site-directed mutagenesis. Structural modeling revealed that MERS-4 binds to RBD only in the "up" position in the S trimer. Furthermore, MERS-4 demonstrated synergy with several reported antibodies. These results indicate that MERS-4 neutralizes MERS-CoV by indirect rather than direct competition with DPP4. This mechanism provides a valuable addition for the combined use of antibodies against MERS-CoV infection.


Assuntos
Anticorpos Neutralizantes/metabolismo , Epitopos/química , Coronavírus da Síndrome Respiratória do Oriente Médio/química , Glicoproteína da Espícula de Coronavírus/química , Sítios de Ligação , Humanos , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Modelos Moleculares , Mutação/genética , Ligação Proteica , Domínios Proteicos , Multimerização Proteica
20.
Dev Cell ; 37(4): 326-336, 2016 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-27219061

RESUMO

Autophagic lysosome reformation (ALR) plays an important role in maintaining lysosome homeostasis. During ALR, lysosomes are reformed by recycling lysosomal components from autolysosomes. The most noticeable step of ALR is autolysosome tubulation, but it is currently unknown how the process is regulated. Here, using an approach combining in vivo studies and in vitro reconstitution, we found that the kinesin motor protein KIF5B is required for autolysosome tubulation and that KIF5B drives autolysosome tubulation by pulling on the autolysosomal membrane. Furthermore, we show that KIF5B directly interacts with PtdIns(4,5)P2. Kinesin motors are recruited and clustered on autolysosomes via interaction with PtdIns(4,5)P2 in a clathrin-dependent manner. Finally, we demonstrate that clathrin promotes formation of PtdIns(4,5)P2-enriched microdomains, which are required for clustering of KIF5B. Our study reveals a mechanism by which autolysosome tubulation was generated.


Assuntos
Autofagia , Cinesinas/metabolismo , Lisossomos/metabolismo , Animais , Clatrina/metabolismo , Lipossomos/metabolismo , Microdomínios da Membrana/metabolismo , Modelos Biológicos , Fosfatidilinositol 4,5-Difosfato/metabolismo , Ratos
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