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1.
Rheumatology (Oxford) ; 60(11): 5397-5407, 2021 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33956056

RESUMO

OBJECTIVE: To evaluate the dose-response, efficacy and safety of dapirolizumab pegol (DZP) in patients with SLE. METHODS: Adults with moderately to severely active SLE (SLEDAI-2K score ≥6 and ≥1 BILAG A or ≥2 BILAG B domain scores), receiving stable CS (≤40 mg/day prednisone-equivalent), antimalarial or immunosuppressant drugs were included. Patients with stable LN (proteinuria ≤2 g/day) not receiving high-dose CS or CYC were permitted entry. Randomized patients received placebo or i.v. DZP (6/24/45 mg/kg) and standard-of-care (SOC) treatment every 4 weeks to week 24, after which patients received only SOC to week 48. The primary objective was to establish a dose-response relationship based on week 24 BILAG-Based Composite Lupus Assessment (BICLA) responder rates. RESULTS: All DZP groups exhibited improvements in clinical and immunological outcomes vs placebo at week 24; however, BICLA responder rates did not fit pre-specified dose-response models [best-fitting model (Emax): P = 0.07]. Incidences of serious treatment-emergent adverse events across DZP groups were low and similar to placebo. Following DZP withdrawal, SLEDAI-2K, physician's global assessment (PGA), BILAG, and Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) scores stabilized; BICLA and SLE Responder Index (SRI-4) responder rates declined (likely due to interventions with disallowed escape medications), BILAG flares increased, and immunologic parameters returned towards baseline. CONCLUSIONS: Although the primary objective was not met, DZP appeared to be well tolerated, and patients exhibited improvements across multiple clinical and immunological measures of disease activity after 24 weeks relative to placebo. The potential clinical benefit of DZP warrants further investigation.


Assuntos
Fragmentos Fab das Imunoglobulinas/uso terapêutico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Polietilenoglicóis/uso terapêutico , Adulto , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Fragmentos Fab das Imunoglobulinas/farmacologia , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/farmacologia , Resultado do Tratamento
2.
Mol Pharm ; 18(3): 1196-1207, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33448219

RESUMO

For active targeting nanodrug delivery systems conjugated with antibodies, both lack of control of the antibody at the molecular level and protein corona formation remarkably decreases targeting efficacy. Herein, we designed a series of silica nanoparticles toward HER2-positive breast cancer cells, with an anti-HER2 Fab-6His density ranging from 50 to 180 molecules per nanoparticle. Through the site-directed immobilization method we developed, the antigen-binding domain of anti-HER2 Fab was mostly accessible to the HER2 receptor. Both polyethylene glycol (PEG) chains and a high density of Fab were shown to suppress protein corona formation and macrophage uptake. The dependency of targeting efficacy and cytotoxicity on Fab density was shown using a series of breast cancer cell lines with different levels of the HER2 expression. The high density of Fab stimulates quick responses from HER2-positive cells. Combined with PEG chains, conjugated antibodies with a well-controlled orientation and density significantly improves delivery performance and sheds light on the design and preparation of an improved active targeting nanodrug delivery system.


Assuntos
Anticorpos/química , Anticorpos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Nanopartículas/química , Receptor ErbB-2/metabolismo , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Imunoconjugados/química , Fragmentos Fab das Imunoglobulinas/química , Células MCF-7 , Polietilenoglicóis/química , Dióxido de Silício/química , Células THP-1
3.
Biomacromolecules ; 22(6): 2491-2504, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-33961407

RESUMO

Metal-chelating polymer-based radioimmunoconjugates (RICs) are effective agents for radioimmunotherapy but are currently limited by nonspecific binding and off-target organ uptake. Nonspecific binding appears after conjugation of the polymer to the antibody and may be related to random lysine conjugation since the polymers themselves do not bind to cells. To investigate the role of conjugation sites on nonspecific binding of polymer RICs, we developed a microbial transglutaminase reaction to prepare site-specific antibody-polymer conjugates. The reaction was enabled by introducing a Q-tag (i.e., 7M48) into antibody (i.e., Fab) fragments and synthesizing a polyglutamide-based metal-chelating polymer with a PEG amine block to yield substrates. Mass spectrometric analyses confirmed that the microbial transglutaminase conjugation reaction was site-specific. For comparison, random lysine conjugation analogs with an average of one polymer per Fab were prepared by bis-aryl hydrazone conjugation. Conjugates were prepared from an anti-frizzled-2 Fab to target the Wnt pathway, along with a nonbinding specificity control, anti-Luciferase Fab. Fabs were engineered from a trastuzumab-based IgG1 framework and lack lysines in the antigen-binding site. Conjugates were analyzed for thermal conformational stability by differential scanning fluorimetry, which showed that the site-specific conjugate had a similar melting temperature to the parent Fab. Binding assays by biolayer interferometry showed that the site-specific anti-frizzled-2 conjugate maintained high affinity to the antigen, while the random conjugate showed a 10-fold decrease in affinity, which was largely due to changes in association rates. Radioligand cell-binding assays on frizzled-2+ PANC-1 cells and frizzled-2- CHO cells showed that the site-specific anti-frizzled-2 conjugate had ca. 4-fold lower nonspecific binding compared to the random conjugate. Site-specific conjugation appeared to reduce nonspecific binding associated with random conjugation of the polymer in polymer RICs.


Assuntos
Imunoconjugados , Polímeros , Animais , Cricetinae , Cricetulus , Fragmentos Fab das Imunoglobulinas , Transglutaminases , Trastuzumab
4.
Int J Mol Sci ; 23(1)2021 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-35008834

RESUMO

Autoimmune endocrine disorders, such as type 1 diabetes (T1D) and thyroiditis, at present are treated with only hormone replacement therapy. This emphasizes the need to identify personalized effective immunotherapeutic strategies targeting T and B lymphocytes. Among the genetic variants associated with several autoimmune disorders, the C1858T polymorphism of the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene, encoding for Lyp variant R620W, affects the innate and adaptive immunity. We previously exploited a novel personalized immunotherapeutic approach based on siRNA delivered by liposomes (lipoplexes) that selectively inhibit variant allele expression. In this manuscript, we improved lipoplexes carrying siRNA for variant C1858T by functionalizing them with Fab of Rituximab antibody (RituxFab-Lipoplex) to specifically target B lymphocytes in autoimmune conditions, such as T1D. RituxFab-Lipoplexes specifically bind to B lymphocytes of the human Raji cell line and of human PBMC of healthy donors. RituxFab-Lipoplexes have impact on the function of B lymphocytes of T1D patients upon CpG stimulation showing a higher inhibitory effect on total cell proliferation and IgM+ plasma cell differentiation than the not functionalized ones. These results might open new pathways of applicability of RituxFab-Lipoplexes, such as personalized immunotherapy, to other autoimmune disorders, where B lymphocytes are the prevalent pathogenic immunocytes.


Assuntos
Linfócitos B/imunologia , Técnicas de Transferência de Genes , Fragmentos Fab das Imunoglobulinas/imunologia , Lipídeos/química , Mutação/genética , Proteína Tirosina Fosfatase não Receptora Tipo 22/genética , RNA Interferente Pequeno/administração & dosagem , Rituximab/imunologia , Sequência de Aminoácidos , Linfócitos B/efeitos dos fármacos , Linhagem Celular , Dicroísmo Circular , Difusão Dinâmica da Luz , Humanos , Lipossomos , Ativação Linfocitária/imunologia , Fenótipo , Proteólise/efeitos dos fármacos , Rituximab/química , Rituximab/farmacologia
5.
J Biomed Sci ; 27(1): 12, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31907057

RESUMO

BACKGROUND: Polyethylene glycol (PEG) is widely used in industry and medicine. Anti-PEG antibodies have been developed for characterizing PEGylated drugs and other applications. However, the underlying mechanism for specific PEG binding has not been elucidated. METHODS: The Fab of two cognate anti-PEG antibodies 3.3 and 2B5 were each crystallized in complex with PEG, and their structures were determined by X-ray diffraction. The PEG-Fab interactions in these two crystals were analyzed and compared with those in a PEG-containing crystal of an unrelated anti-hemagglutinin 32D6-Fab. The PEG-binding stoichiometry was examined by using analytical ultracentrifuge (AUC). RESULTS: A common PEG-binding mode to 3.3 and 2B5 is seen with an S-shaped core PEG fragment bound to two dyad-related Fab molecules. A nearby satellite binding site may accommodate parts of a longer PEG molecule. The core PEG fragment mainly interacts with the heavy-chain residues D31, W33, L102, Y103 and Y104, making extensive contacts with the aromatic side chains. At the center of each half-circle of the S-shaped PEG, a water molecule makes alternating hydrogen bonds to the ether oxygen atoms, in a similar configuration to that of a crown ether-bound lysine. Each satellite fragment is clamped between two arginine residues, R52 from the heavy chain and R29 from the light chain, and also interacts with several aromatic side chains. In contrast, the non-specifically bound PEG fragments in the 32D6-Fab crystal are located in the elbow region or at lattice contacts. The AUC data suggest that 3.3-Fab exists as a monomer in PEG-free solution but forms a dimer in the presence of PEG-550-MME, which is about the size of the S-shaped core PEG fragment. CONCLUSIONS: The differing amino acids in 3.3 and 2B5 are not involved in PEG binding but engaged in dimer formation. In particular, the light-chain residue K53 of 2B5-Fab makes significant contacts with the other Fab in a dimer, whereas the corresponding N53 of 3.3-Fab does not. This difference in the protein-protein interaction between two Fab molecules in a dimer may explain the temperature dependence of 2B5 in PEG binding, as well as its inhibition by crown ether.


Assuntos
Anticorpos Monoclonais Murinos/química , Especificidade de Anticorpos , Sítios de Ligação de Anticorpos , Fragmentos Fab das Imunoglobulinas/química , Polietilenoglicóis/química , Cristalografia por Raios X
6.
Nature ; 516(7530): 213-8, 2014 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-25337878

RESUMO

Bestrophin calcium-activated chloride channels (CaCCs) regulate the flow of chloride and other monovalent anions across cellular membranes in response to intracellular calcium (Ca(2+)) levels. Mutations in bestrophin 1 (BEST1) cause certain eye diseases. Here we present X-ray structures of chicken BEST1-Fab complexes, at 2.85 Å resolution, with permeant anions and Ca(2+). Representing, to our knowledge, the first structure of a CaCC, the eukaryotic BEST1 channel, which recapitulates CaCC function in liposomes, is formed from a pentameric assembly of subunits. Ca(2+) binds to the channel's large cytosolic region. A single ion pore, approximately 95 Å in length, is located along the central axis and contains at least 15 binding sites for anions. A hydrophobic neck within the pore probably forms the gate. Phenylalanine residues within it may coordinate permeating anions via anion-π interactions. Conformational changes observed near the 'Ca(2+) clasp' hint at the mechanism of Ca(2+)-dependent gating. Disease-causing mutations are prevalent within the gating apparatus.


Assuntos
Cálcio/metabolismo , Galinhas , Canais de Cloreto/química , Canais de Cloreto/metabolismo , Animais , Sítios de Ligação , Cálcio/análise , Cálcio/química , Cálcio/farmacologia , Canais de Cloreto/imunologia , Cloretos/química , Cloretos/metabolismo , Cristalografia por Raios X , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/imunologia , Ativação do Canal Iônico , Transporte de Íons , Lipossomos/química , Lipossomos/metabolismo , Modelos Moleculares , Relação Estrutura-Atividade
7.
Biol Pharm Bull ; 43(3): 418-423, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31866612

RESUMO

Conjugation with polyethylene glycol (PEG) is performed to increase serum half-life of the Fab for clinical applications. However, current designs for recombinant Fab only allow PEGylation at the interchain SS bond (disulfide bond) at the C-terminal end of the heavy chain and light chain of the Fab, which the decrease of thermostability occurred by partial reduction of the interchain SS bond. An adalimumab Fab mutant with a novel interchain SS bond (CH1 : C177-CL : C160) and one cysteine at the C-terminal end (mutSS FabSH) was designed to maintain Fab thermostability and for site-specific PEGylation. MutSS FabSH was expressed in Pichia pastoris and purified mutSS FabSH was conjugated with 20-kDa PEG targeted at the free cysteine. Based on enzyme-linked immunosorbent assay (ELISA), PEGylation did not affect the binding capacity of the mutSS FabSH. To confirm the influence of PEGylation on the pharmacokinetic behavior of the Fab, PEGylated mutSS FabSH was administered to rats via tail vein injection. Analysis of the mean serum concentration of the PEGylated mutSS FabSH versus time through ELISA indicated an increase in half-life compared to that of non-PEGylated wild-type Fab. Consequently, we have successfully demonstrated that a Fab mutant with a novel interchain SS bond and one free cysteine at the C-terminal end can be PEGylated without changes in functionality. This design can potentially be used as a platform for modification of other recombinant Fabs.


Assuntos
Adalimumab/química , Fragmentos Fab das Imunoglobulinas/química , Animais , Cisteína/química , Masculino , Mutação , Polietilenoglicóis/química , Ratos , Ratos Sprague-Dawley
8.
Anal Chem ; 91(13): 8484-8491, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31247713

RESUMO

Multiplex detection techniques are emerging within the fields of life science research and medical diagnostics where it is mandatory to analyze a great number of molecules. The detection techniques need to be highly efficient but often involve complicated and expensive fabrication procedures. Here, we present the immobilization and geometric separation of fluorescence-labeled microbeads for a multiplex detection in k levels. A compound of differently sized target molecules (DNA, proteins) is channeled into the respective detection levels by making use of a hydrogel as a size selective filter. The immobilized microbeads (10-20 µm) are considerably larger than the pores of the hydrogel network and therefore stay fixed at the well bottom and in higher elevations, respectively. Small biomolecules can diffuse through the pores of the network, whereas medium-sized biomolecules pass slower and large molecules will be excluded. Besides filtering, this method discriminates the used microbeads into k levels and thereby introduces a geometric multiplexity. Additionally, the exclusion of large entities enables the simultaneous detection of two target molecules, which exhibit the same affinity interaction. The hydrogel is formed through the combination of two macromonomers. One component is a homobifunctional polyethylene glycol linker, carrying a strained alkyne (PEG-BCN) and the second component is the azide-functionalized dendritic polyglycerol (dPG-N3). They react via the bioorthogonal strain-promoted azide alkyne cycloaddition (SPAAC). The hydrogel creates a solution-like environment for the diffusion of the investigated biomolecules all the while providing a stable, bioinert, and surface bound network.


Assuntos
Materiais Biocompatíveis/química , Glicerol/química , Hidrogéis/química , Fragmentos Fab das Imunoglobulinas/química , Microesferas , Polímeros/química , Alcinos , Azidas , Catálise , Química Click
9.
Rheumatology (Oxford) ; 58(3): 382-387, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29660084

RESUMO

SLE has a complex pathogenesis, and multiple therapeutic targets have been discovered in recent years. In spite of belimumab being approved by the US Food and Drug Administration and the widespread use of rituximab, there have been many failed attempts to treat SLE successfully using biologic agents. In this review, we consider newer biologic approaches that might offer the hope of improving the outcome of SLE patients. These include the fully humanized anti-CD20 mAbs, PEGylated anti-CD40L, IFNα inhibitors, rigerimod and immune complexes blockade.


Assuntos
Produtos Biológicos/uso terapêutico , Fatores Imunológicos/uso terapêutico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Anticorpos Monoclonais Humanizados/uso terapêutico , Humanos , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Rituximab/uso terapêutico , Resultado do Tratamento
10.
Phys Biol ; 16(3): 035002, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-30769341

RESUMO

The single-molecule pull-down (SiMPull) assay analyzes molecular complexes in physiological conditions from cell or tissue lysates. Currently the approach requires a lengthy sample preparation process, which has largely prevented the widespread adoption of this technique in bioanalysis. Here, we present a simplified SiMPull assay based upon dichlorodimethylsilane-Tween-20 passivation and F(ab) fragment labeling. Our passivation is a much shorter process than the standard polyethylene glycol passivation used in most single-molecule studies. The use of F(ab) fragments for indirect fluorescent labeling rather than divalent F(ab')2 or whole IgG antibodies allows for the pre-incubation of the detection antibodies, reducing the sample preparation time for single-molecule immunoprecipitation samples. We examine the applicability of our approach to recombinant proteins and endogenous proteins from mammalian cell lysates.


Assuntos
Fragmentos Fab das Imunoglobulinas/análise , Imunoglobulina G/análise , Polissorbatos/química , Silanos/química , Reações Antígeno-Anticorpo , Humanos , Imunoprecipitação , Microscopia de Fluorescência
11.
Clin Exp Rheumatol ; 37(6): 1010-1018, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30963993

RESUMO

OBJECTIVES: Smoking has been shown to influence rheumatoid arthritis (RA) severity and reduce response to some anti-tumour necrosis factor (anti-TNF) therapies. CIMDORA assessed the association between cigarette smoking and clinical effectiveness of certolizumab pegol (CZP) in Hungarian, Slovak, and Czech RA patients. METHODS: CIMDORA was a prospective, non-interventional, 104-week study (Feb 2011-Aug 2015). The primary endpoint was association between change in 28-joint Disease Activity Score (DAS28[ESR]) from baseline to Week 12, and baseline cigarette pack-year history. Secondary endpoints included association between change in DAS28(ESR) and daily number of cigarettes smoked. The full analysis set (FAS) included all patients receiving ≥1 dose of CZP with all necessary assessments for the primary endpoint. Treatment-emergent adverse events (TEAEs) were reported for all patients receiving ≥1 dose of CZP. RESULTS: The FAS included 218/273 enrolled patients: 155 Hungarian, 46 Czech and 17 Slovak. Hungarian and Czech patients completed 104 weeks (n=141); Slovak patients completed 52 weeks. Mean change in DAS28(ESR) [SD] at Week 12 (-2.78 [1.47]) was not significantly associated with baseline cigarette pack-year history (slope estimate [SE]: 0.03, 95% confidence interval [CI]: -0.16, 0.21 [p=0.77]). Mean DAS28(ESR) [SD] reductions to Week 52 (-3.33 [1.33]) were not significantly associated with daily number of cigarettes smoked in the previous month (SE: 0.001, CI: -0.05, 0.05 [p=0.95]). Two deaths were reported but neither of them was related to CZP. No new safety signals were identified and the safety profile was consistent with previous CZP studies. CONCLUSIONS: After 104 weeks of CZP treatment, patients demonstrated similar DAS28(ESR) improvements, irrespective of smoking history.


Assuntos
Antirreumáticos , Artrite Reumatoide , Certolizumab Pegol/uso terapêutico , Fumar Cigarros , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , República Tcheca , Quimioterapia Combinada , Humanos , Hungria , Fragmentos Fab das Imunoglobulinas , Metotrexato , Polietilenoglicóis , Estudos Prospectivos , Eslováquia , Resultado do Tratamento , Fator de Necrose Tumoral alfa
12.
Nanomedicine ; 17: 13-25, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30654186

RESUMO

Immunoliposomes (ILs), obtained with monoclonal antibodies (mAbs) decorating the liposome surface, are used for cancer treatment. These mAbs provide the recognition of molecules upregulated in cancer cells, like Programmed Death-Ligand 1 (PD-L1), an immune-checkpoint involved in tumor resistance, forming a complex that blocks this molecule and thereby, induces antitumor immune response. This mechanism introduces a new concept for ILs. ILs coupled to anti-PD-L1 or its Fab' fragment have been developed and in vitro/in vivo characterized. Factors such as coupling methods, PEG density and ligand size were optimized. In vitro data showed that Fab'-ILs displayed the highest PD-L1 cell interaction, correlating with a higher in vivo tumor accumulation and an increase of effector cytotoxic CD8+ T cells, providing tumor shrinkage and total regression in 20% of mice. Therefore, a novel immune-nanoplatform able to modulate the immune system has been developed, allowing the encapsulation of several agents for combinatorial therapies.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Antineoplásicos Imunológicos/administração & dosagem , Fragmentos Fab das Imunoglobulinas/administração & dosagem , Neoplasias/terapia , Receptor de Morte Celular Programada 1/imunologia , Imunidade Adaptativa/efeitos dos fármacos , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos Imunológicos/imunologia , Antineoplásicos Imunológicos/uso terapêutico , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Feminino , Fragmentos Fab das Imunoglobulinas/imunologia , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Imunoterapia , Lipossomos , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/imunologia
13.
Biochim Biophys Acta Biomembr ; 1860(6): 1318-1325, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29501600

RESUMO

Previously a scalable and extrusion-free method has been developed for efficient liposomal encapsulation of DNA by twice stepwise mixing of lipids in ethanol and DNA solution using T-shape mixing chamber. In this study, we prepared nanoliposomes encapsulating siRNA by simply discontinuous mixing of lipids in ethanol/ether/water mixture and acidic siRNA solution without use of special equipment. The simple mixing siRNA/liposomal particles (siRNA/SMLs) prepared using ethanol/ether/water (3:1:1) mixture showed 120.4 ±â€¯20.2 nm particle size, 0.174 ±â€¯0.033 polydispersity and 86.5 ±â€¯2.76% siRNA encapsulation rate. In addition, the SMLs almost completely protected the encapsulated siRNA from RNase A digestion. Coupling of anti-human epidermal growth factor receptor (EGFR) Fab' to siRNA/SMLs enhanced EGFR-specific cell penetration of SMLs and induced siRNA dependent gene silencing. Unexpectedly, the Cy5.5-labeled Fab' showed almost no in vivo targeting to the xenografted A549 tumors in SCID-NOD mice. However, multiple injection of the unmodified siRNA/SMLs accumulated in the tumors and induced siRNA-dependent in vivo gene silencing. These results demonstrate that the siRNA/SMLs can be used as a siRNA delivery tool for gene therapy.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Lipossomos , Nanoestruturas , RNA Interferente Pequeno/administração & dosagem , Animais , Composição de Medicamentos , Receptores ErbB/antagonistas & inibidores , Humanos , Fragmentos Fab das Imunoglobulinas , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Terapia de Alvo Molecular , Células NIH 3T3 , Proteínas de Neoplasias/antagonistas & inibidores , Tamanho da Partícula , Interferência de RNA , RNA Interferente Pequeno/farmacocinética , Ensaios Antitumorais Modelo de Xenoenxerto
14.
PLoS Pathog ; 12(3): e1005454, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26938634

RESUMO

Enterovirus 71 (EV71) is the main pathogen responsible for hand, foot and mouth disease with severe neurological complications and even death in young children. We have recently identified a highly potent anti-EV71 neutralizing monoclonal antibody, termed D5. Here we investigated the structural basis for recognition of EV71 by the antibody D5. Four three-dimensional structures of EV71 particles in complex with IgG or Fab of D5 were reconstructed by cryo-electron microscopy (cryo-EM) single particle analysis all at subnanometer resolutions. The most critical EV71 mature virion-Fab structure was resolved to a resolution of 4.8 Å, which is rare in cryo-EM studies of virus-antibody complex so far. The structures reveal a bivalent binding pattern of D5 antibody across the icosahedral 2-fold axis on mature virion, suggesting that D5 binding may rigidify virions to prevent their conformational changes required for subsequent RNA release. Moreover, we also identified that the complementary determining region 3 (CDR3) of D5 heavy chain directly interacts with the extremely conserved VP1 GH-loop of EV71, which was validated by biochemical and virological assays. We further showed that D5 is indeed able to neutralize a variety of EV71 genotypes and strains. Moreover, D5 could potently confer protection in a mouse model of EV71 infection. Since the conserved VP1 GH-loop is involved in EV71 binding with its uncoating receptor, the scavenger receptor class B, member 2 (SCARB2), the broadly neutralizing ability of D5 might attribute to its inhibition of EV71 from binding SCARB2. Altogether, our results elucidate the structural basis for the binding and neutralization of EV71 by the broadly neutralizing antibody D5, thereby enhancing our understanding of antibody-based protection against EV71 infection.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Enterovirus Humano A/imunologia , Modelos Moleculares , Animais , Sequência de Bases , Chlorocebus aethiops , Microscopia Crioeletrônica , Enterovirus Humano A/química , Enterovirus Humano A/genética , Enterovirus Humano A/ultraestrutura , Humanos , Fragmentos Fab das Imunoglobulinas/imunologia , Imunoglobulina G/imunologia , Camundongos , Conformação Molecular , Dados de Sequência Molecular , Mutação , Receptores Depuradores/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Células Vero , Vírion/química
15.
Cytokine ; 101: 56-63, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-27567553

RESUMO

Tumor necrosis factor (TNF)-α is a potent pro-inflammatory and pathological cytokines in inflammatory diseases such as rheumatoid arthritis and inflammatory bowel diseases. Anti-TNF-α therapy has been established as an efficacious therapeutic strategy in these diseases. In clinical settings, three monoclonal anti-TNF-α full IgG1 antibodies infliximab, adalimumab, and golimumab, PEGylated Fab' fragment of anti-TNF-α antibody certolizumab pegol, extracellular domain of TNF receptor 2/IgG1-Fc fusion protein etanercept, are almost equally effective for rheumatoid arthritis. Although monoclonal full IgG1 antibodies are able to induce clinical and endoscopic remission in inflammatory bowel diseases, certolizumab pegol without Fc portion has been shown to be less effective for inflammatory bowel diseases compared to full IgG1 antibodies. In addition, there are no evidences that etanercept leads clinical remission in inflammatory bowel diseases. Besides the common effect of anti-TNF-α agents on neutralization of soluble TNF-α, each anti-TNF-α agent has its own distinctive pharmacological properties which cause the difference in clinical efficacies. Here we focus on the distinctions of action of anti-TNF-α agents especially in following points; (1) blocking ability against ligands, transmembrane TNF-α and lymphotoxin, (2) effects toward transmembrane TNF-α-expressing cells, (3) effects toward Fcγ receptor-expressing cells, (4) degradation and distribution in inflamed tissue. Accumulating evidence will give us the idea how to modify anti-TNF-α agents to enhance the clinical efficacy in inflammatory diseases.


Assuntos
Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/genética , Artrite Reumatoide/tratamento farmacológico , Imunoglobulina G/uso terapêutico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adalimumab/efeitos adversos , Adalimumab/genética , Adalimumab/uso terapêutico , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Anti-Inflamatórios/uso terapêutico , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/uso terapêutico , Antirreumáticos/administração & dosagem , Antirreumáticos/efeitos adversos , Antirreumáticos/uso terapêutico , Artrite Reumatoide/imunologia , Certolizumab Pegol/efeitos adversos , Certolizumab Pegol/genética , Certolizumab Pegol/uso terapêutico , Modelos Animais de Doenças , Etanercepte/efeitos adversos , Etanercepte/uso terapêutico , Humanos , Fragmentos Fab das Imunoglobulinas/efeitos adversos , Fragmentos Fab das Imunoglobulinas/genética , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Imunoglobulina G/efeitos adversos , Imunoglobulina G/genética , Fatores Imunológicos/efeitos adversos , Fatores Imunológicos/genética , Fatores Imunológicos/uso terapêutico , Imunossupressores/administração & dosagem , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Doenças Inflamatórias Intestinais/imunologia , Infliximab/efeitos adversos , Infliximab/genética , Infliximab/uso terapêutico , Camundongos , Polietilenoglicóis/uso terapêutico , Fator de Necrose Tumoral alfa/imunologia
16.
Biomacromolecules ; 19(7): 3086-3095, 2018 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-29890078

RESUMO

Antibody and related antibody drugs for the treatment of malignancies have led to progress in targeted cancer therapy. Preparation of diverse antibody conjugates is critical for preclinical and clinical applications. However, precise control in tagging molecules at specific locations on antibodies is essential to preserve their native function. In this study, a synthetic boronic acid (BA)-tosyl initiator was used to trigger a glycan-directed modification of IgGs, and the obtained IgG macroinitiators allowed a growth of the poly N-isopropylacrylamide (PNIPAAm) chains specifically at Fc-domains. Therefore, the PNIPAAm chains are located away from the critical antigen-binding domains (Fab), which could reasonably prevent the loss of biological activity after the attachment of polymer chains. According to the proposed strategy, a site-selectively modified anticoncanavalin A (Con A) antibody-PNIPAAm conjugate showed 6-times higher efficiency in the binding of targeted Con A antigen to a randomly conjugated anti-Con A antibody-PNIPAAm conjugate. In this study, we developed the first chemical strategy for the site-specific preparation of IgG-polymer conjugates with conserved biological activity as well as intact glycan structures.


Assuntos
Imunoglobulina G/química , Polissacarídeos/química , Resinas Acrílicas/química , Concanavalina A/imunologia , Fragmentos Fab das Imunoglobulinas/química , Imunoglobulina G/imunologia , Polimerização
17.
Biomacromolecules ; 19(6): 2320-2329, 2018 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-29767505

RESUMO

Antibody fragment (Fab')-installed polyion complex (PIC) micelles were constructed to improve targetability of small interfering RNA (siRNA) delivery to pancreatic cancer cells. To this end, we synthesized a block copolymer of azide-functionalized poly(ethylene glycol) and poly(l-lysine) and prepared PIC micelles with siRNA. Then, a dibenzylcyclooctyne (DBCO)-modified antihuman tissue factor (TF) Fab' was conjugated to azido groups on the micellar surface. A fluorescence correlation spectroscopic analysis revealed that 1, 2, or 3 molecule(s) of Fab'(s) were installed onto one micellar nanoparticle according to the feeding ratio of Fab' (or DBCO) to micelle (or azide). The resulting micelles exhibited ∼40 nm in hydrodynamic diameter, similar to that of the parent micelles before Fab' conjugation. Flow cytometric analysis showed that three molecules of Fab'-installed PIC micelles (3(Fab')-micelles) had the highest binding affinity to cultured pancreatic cancer BxPC3 cells, which are known to overexpress TF on their surface. The 3(Fab')-micelles also exhibited the most efficient gene silencing activity against polo-like kinase 1 mRNA in the cultured cancer cells. Furthermore, the 3(Fab')-micelles exhibited high penetrability and the highest cellular internalization amounts in BxPC3 spheroids compared with one or two molecule(s) of Fab'-installed PIC micelles. These results demonstrate the potential of anti-TF Fab'-installed PIC micelles for active targeting of stroma-rich pancreatic tumors.


Assuntos
Anticorpos Antineoplásicos , Proteínas de Ciclo Celular/antagonistas & inibidores , Sistemas de Liberação de Medicamentos , Inativação Gênica , Fragmentos Fab das Imunoglobulinas , Micelas , Neoplasias Pancreáticas/tratamento farmacológico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , RNA Interferente Pequeno , Tromboplastina/antagonistas & inibidores , Anticorpos Antineoplásicos/química , Anticorpos Antineoplásicos/farmacologia , Proteínas de Ciclo Celular/biossíntese , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Humanos , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/farmacologia , Neoplasias Pancreáticas/enzimologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Polilisina/química , Polilisina/farmacologia , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas/genética , RNA Interferente Pequeno/química , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Tromboplastina/metabolismo , Quinase 1 Polo-Like
19.
Nanomedicine ; 14(1): 123-130, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28939491

RESUMO

Liposomes functionalized with monoclonal antibodies or their antigen-binding fragments have attracted much attention as specific drug delivery devices for treatment of various diseases including cancer. The conjugation of antibodies to liposomes is usually achieved by covalent coupling using cross-linkers in a reaction that might adversely affect the characteristics of the final product. Here we present an alternative strategy for liposome functionalization: we created a recombinant Fab antibody fragment genetically fused on its C-terminus to the hydrophobic peptide derived from pulmonary surfactant protein D, which became inserted into the liposomal bilayer during liposomal preparation and anchored the Fab onto the liposome surface. The Fab-conjugated liposomes specifically recognized antigen-positive cells and efficiently delivered their cargo, the Alexa Fluor 647 dye, into target cells in vitro and in vivo. In conclusion, our approach offers the potential for straightforward development of nanomedicines functionalized with an antibody of choice without the need of harmful cross-linkers.


Assuntos
Anticorpos Monoclonais/imunologia , Fragmentos Fab das Imunoglobulinas/imunologia , Lipossomos/química , Linfoma/imunologia , Fragmentos de Peptídeos/imunologia , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/metabolismo , Antígeno CD48/metabolismo , Antígenos CD59/metabolismo , Humanos , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/metabolismo , Células Jurkat , Linfoma/metabolismo , Linfoma/patologia , Camundongos , Fragmentos de Peptídeos/metabolismo , Proteína D Associada a Surfactante Pulmonar/imunologia , Proteína D Associada a Surfactante Pulmonar/metabolismo , Células Tumorais Cultivadas
20.
Ter Arkh ; 90(4): 50-54, 2018 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-30701874

RESUMO

AIM: To assess the effectiveness of conservative treatment of Crohn's disease (CD) with perianal lesions. MATERIALS AND METHODS: The study included 20 patients with CD with perianal fistulae. Prior to the start of conservative therapy, 7 patients underwent fistulae drainage with setton placement. During the study, all patients received therapy with certolizumab pegol (CP) for a year. At the time of treatment initiation and after 12 months, the CD activity index, the quality of life according to IBDQ questionnaires and the perianal Crohn's disease activity index (PCDAI) were assessed. RESULTS: After a year of CP therapy, clinical remission was achieved in 8 (40%) patients, endoscopic remission in 7 (35%) patients, fistula closure in 6 (30%) patients. There was also a decrease in the PCDAI with the average score 3.6 points compared to 9.3 points (p˂0.05) prior to the treatment. An improvement in the quality of life of patients was also established, the average quality of life index was 182,2 points compared to 156,0 points (p˂0.05) prior to the treatment. CONCLUSION: This study showed that CP therapy is effective in treatment of CD with perianal lesions.


Assuntos
Anticorpos Monoclonais Humanizados , Certolizumab Pegol , Doença de Crohn , Anticorpos Monoclonais Humanizados/uso terapêutico , Certolizumab Pegol/uso terapêutico , Doença de Crohn/tratamento farmacológico , Humanos , Fragmentos Fab das Imunoglobulinas , Polietilenoglicóis , Qualidade de Vida , Resultado do Tratamento
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