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Heated tobacco products (HTPs) are an emerging class of tobacco goods that claim to have lower health risks than those of smoking combustible tobacco products. In this study, we exposed human lung epithelial cell lines to extracts prepared from HTP aerosols and combustible cigarette smoke to compare cytotoxicity. We focused on the effects of aldehydes present in the aerosols of HTPs at levels close to those in combustible cigarette smoke. Significant toxicity was confirmed for the HTP extract, albeit to a lesser extent than that with the combustible cigarette extract. When redox balance was evaluated by the oxidative loss of low-molecular-weight thiols in the cells, we found that total glutathione (GSH) contents and low-molecular-weight thiol levels were significantly decreased after exposure to the aerosol extract of HTPs. These results indicated that GSH is rapidly consumed during the detoxification of xenobiotics, such as aldehydes from tobacco extracts. Accordingly, exposure to the aerosol extract of HTPs resulted in the enhanced carbonylation of many proteins. In a simple comparison, the results for HTPs were significantly different from those obtained with combustible cigarette smoke, suggesting reduced toxicity of HTPs. However, we found significant and harmful effects after exposing lung epithelial cells to the aerosol extract of HTPs. Thus, a further comprehensive study is needed to clarify the lung damage induced via the long-term inhalation of aerosols from HTPs.
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Aerossóis/efeitos adversos , Células Epiteliais/metabolismo , Glutationa/metabolismo , Temperatura Alta , Pulmão/patologia , Nicotiana/química , Carbonilação Proteica , Células A549 , Morte Celular , Gases , Humanos , Peso Molecular , Compostos de Sulfidrila/metabolismo , Produtos do Tabaco , VolatilizaçãoRESUMO
Combined sewer overflows (CSOs) pollute receiving waters and have a negative impact on ecosystem services. In urban areas rehabilitation of the sewer system to avoid CSOs is associated with high investment costs. Furthermore, not all CSOs can be closed due to the need for hydraulic reliability of the system. Local treatment of CSO with high rate filtration offers an alternative to rehabilitation of the sewer system that is flexible with respect to design and has lower investment cost than separating sewage and storm water runoff. Results from DESSIN, a 4-year EU demonstration project, are presented. The results showed on average 50% removal of particulate matter during CSO events, with higher removal (80%) in the initial first flush period. Other constituents, for example heavy metals, were removed through their association with particles. Potential impacts on ecosystem services in the catchment and the sustainability of the solution were assessed.
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Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/estatística & dados numéricos , Metais Pesados/análise , Reprodutibilidade dos Testes , Esgotos , Poluentes da Água/análiseRESUMO
PurposeTo compare optical coherence tomographic angiography (OCTA) and indocyanine green angiography (ICGA) images for detecting polypoidal lesions (PLs) and branching vascular networks (BVNs), and to measure the polypoidal areas (PAs) in patients with polypoidal choroidal vasculopathy (PCV).MethodsAll patients underwent ICGA, optical coherence tomography (OCT), and OCTA. We compared the detection sensitivity for PL and BVN, as evaluated by the ICGA and OCTA images. Furthermore, PA measured by ICGA was divided into two groups: one in which the area could be measured by OCTA (ICGA+OCTA+) and the other in which the area could not be measured by OCTA (ICGA+OCTA-).ResultsTwenty-one consecutive eyes of 21 patients (mean age, 73.8±9.8 years) were included. ICGA detected PL in all eyes (100%), whereas OCTA detected PL in 16 eyes (75.2%); ICGA detected BVN in 15 eyes (71.4%), whereas OCTA detected BVN in 20 eyes (95.2%). The mean PA in ICGA+OCTA+ and ICGA+OCTA- was 0.24±0.04 and 0.14±0.01 mm2, respectively; a significant difference was observed between ICGA+OCTA+ PA and ICGA+OCTA- PA (P<0.0001). In addition, the mean PA in the ICGA+OCTA+ group measured by ICGA and OCTA was 0.24±0.04 was 0.19±0.04 mm2, respectively; these values were significantly different (P=0.0046).ConclusionsOCTA might detect more BVNs and fewer PLs compared with ICGA, and PL detected by OCTA might be smaller than those detected by ICGA.
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Doenças da Coroide/diagnóstico por imagem , Corioide/irrigação sanguínea , Angiofluoresceinografia/métodos , Imagem Óptica/métodos , Pólipos/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Idoso , Idoso de 80 Anos ou mais , Corioide/patologia , Doenças da Coroide/patologia , Neovascularização de Coroide/diagnóstico por imagem , Corantes/administração & dosagem , Feminino , Humanos , Verde de Indocianina/administração & dosagem , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Impaired exercise capacity and muscle weakness are important characteristics of liver transplantation recipients. Perioperative rehabilitation has been introduced to promote early mobilization of patients and to prevent postoperative pulmonary complications. However, it is unknown how physical status recovers during the hospital stay after a liver transplant. The purpose of this study was to evaluate the changes in clinical indicators that represent the functional exercise capacity and muscle strength before and after living donor liver transplantation (LDLT). METHODS: We retrospectively reviewed 21 consecutive patients who underwent LDLT with perioperative rehabilitation from April 2014 to December 2015. Twelve patients who were tested for 6-minute walk distance, hand-grip strength, and isometric knee extensor muscle strength before and 4 weeks after LDLT were enrolled. RESULTS: At the preoperative baseline, the 6-minute walk distance significantly correlated with the Model for End-stage Liver Disease score and pulmonary functions (vital capacity, forced vital capacity, and forced expiratory volume in 1 second of predictive values). Comparisons between the preoperative and postoperative values revealed significant decreases in weight, Barthel Index, hand-grip strength, and isometric knee extensor muscle strength. Changes in hand-grip strength and isometric knee extensor muscle strength after LDLT correlated with the preoperative Model for End-stage Liver Disease score. CONCLUSIONS: Physical functional status had not been fully recovered 4 weeks after LDLT. Further investigation regarding developing a strategy for prevention of muscle atrophy before LDLT and recovery of physical fitness after LDLT would be helpful.
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Cirrose Hepática/fisiopatologia , Transplante de Fígado/reabilitação , Doadores Vivos , Força Muscular , Teste de Caminhada , Adulto , Idoso , Feminino , Volume Expiratório Forçado , Força da Mão , Humanos , Joelho/fisiopatologia , Cirrose Hepática/reabilitação , Cirrose Hepática/cirurgia , Transplante de Fígado/métodos , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Aptidão Física/fisiologia , Período Pós-Operatório , Período Pré-Operatório , Estudos Retrospectivos , Índice de Gravidade de Doença , Capacidade VitalAssuntos
Artéria Carótida Primitiva/diagnóstico por imagem , Cateterismo Venoso Central/métodos , Competência Clínica/estatística & dados numéricos , Veias Jugulares/diagnóstico por imagem , Estudantes de Medicina/estatística & dados numéricos , Ultrassonografia/métodos , Educação Médica/métodos , HumanosRESUMO
The pH-dependent antigen binding antibody, termed a recycling antibody, has recently been reported as an attractive type of second-generation engineered therapeutic antibody. A recycling antibody can dissociate antigen in the acidic endosome, and thus bind to its antigen multiple times. As a consequence, a recycling antibody can neutralize large amounts of antigen in plasma. Because this approach relies on histidine residues to achieve pH-dependent antigen binding, which could limit the epitopes that can be targeted and affect the rate of antigen dissociation in the endosome, we explored an alternative approach for generating recycling antibodies. Since calcium ion concentration is known to be lower in endosome than in plasma, we hypothesized that an antibody with antigen-binding properties that are calcium-dependent could be used as recycling antibody. Here, we report a novel anti-interleukin-6 receptor (IL-6R) antibody, identified from a phage library that binds to IL-6R only in the presence of a calcium ion. Thermal dynamics and a crystal structure study revealed that the calcium ion binds to the heavy chain CDR3 region (HCDR3), which changes and possibly stabilizes the structure of HCDR3 to make it bind to antigen calcium dependently (PDB 5AZE). In vitro and in vivo studies confirmed that this calcium-dependent antigen-binding antibody can dissociate its antigen in the endosome and accelerate antigen clearance from plasma, making it a novel approach for generating recycling antibody.
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Antígenos , Cálcio , Endossomos , Receptores de Interleucina-6 , Anticorpos de Cadeia Única , Antígenos/química , Antígenos/metabolismo , Cálcio/química , Cálcio/metabolismo , Linhagem Celular , Regiões Determinantes de Complementaridade/química , Regiões Determinantes de Complementaridade/metabolismo , Endossomos/química , Endossomos/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Receptores de Interleucina-6/química , Receptores de Interleucina-6/metabolismo , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/metabolismoRESUMO
We assessed the association between obesity measurements including visceral adipose tissue (VAT), measured by computed tomography, and the risk of high-grade prostate cancer after radical prostatectomy. We investigated 296 patients who were diagnosed with prostate cancer and underwent radical prostatectomy. Data extracted from medical records included age, body mass index (BMI), VAT, pretreatment prostate-specific antigen (PSA) levels and Gleason score (GS). We performed logistic regression to examine the association between indicators of obesity and a higher GS (⩾4+3). Among the 296 patients, 107 (36%) had a higher GS. After controlling for age and PSA, BMI was not associated with GS (odds ratio, OR=1.039, 95% confidence interval, CI=0.943-1.145; P=0.437). BMI had different effects on GS depending on VAT. When the data were stratified by the median VAT value, a higher BMI was significantly associated with a higher GS in patients with VAT⩾130.5 cm2 (OR=1.218, 95% CI=1.028-1.443; P=0.022), but not in those with VAT<130.5 cm2 (OR=0.912, 95% CI=0.783-1.062; P=0.236). A higher BMI was associated with an increased risk of high-grade cancer only in patients with more VAT.
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Recidiva Local de Neoplasia/patologia , Obesidade Abdominal/complicações , Prostatectomia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Tomografia Computadorizada por Raios X , Idoso , Biomarcadores Tumorais/sangue , Índice de Massa Corporal , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico por imagem , Obesidade Abdominal/diagnóstico por imagem , Obesidade Abdominal/patologia , Modelos de Riscos Proporcionais , Antígeno Prostático Específico/sangue , Prostatectomia/efeitos adversos , Neoplasias da Próstata/sangue , Fatores de RiscoRESUMO
BACKGROUND: A small accessory facet with articular surface morphology is occasionally seen on the talus, bordering on the lateral end of the sinus tarsi. This facet has been named the accessory anterolateral talar facet. However, few anatomical studies have addressed this facet. Here we present the precise morphology of accessory anterolateral talar facet with emphasis on anatomical correlation between the presence of this facet and the angle of the infero-lateral surface of the talus (talar infero-lateral surface - TILS angle). MATERIALS AND METHODS: A total of 22 (11 male, 11 female) adult cadavers with no known pathological conditions in the talocalcaneal joints were examined during educational dissection at Nagoya City University Medical School in 2013. After exclusion of 1 joint due to the poor condition of the talus, 43 talus (22 right, 21 left) were analysed. We judged the presence of the accessory anterolateral talar facet and measured TILS angle. We performed statistical analysis on the point of laterality, gender difference and the difference in the TILS angles in tali with or without the accessory anterolateral talar facets. RESULTS: An accessory anterolateral talar facet was identified in 11 (26%) of the 43 specimens. Of the 21 cadavers with paired talar specimens, 5 displayed the facet bilaterally. CONCLUSIONS: There was no sex difference and no significant laterality, however we found that TILS angle was significantly larger in accessory anterolateral talar facet positive samples than in negative ones.
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Synthetic glucocorticoids such as dexamethasone are widely used to treat a variety of inflammatory and autoimmune conditions, but they may induce adverse events including hyperglycemia. To shed light on the effect and action mechanism of dexamethasone, we examined the alterations of gene expression levels caused by dexamethasone.Microarray analysis was performed on whole blood collected from 24 physically healthy subjects at baseline and after dexamethasone administration. The expression levels of resistin mRNA were found to be significantly increased after the dexamethasone administration. In a separate sample of 12 subjects, we examined plasma resistin protein levels and found that they were increased after dexamethasone administration. Furthermore, the plasma mRNA and protein levels of resistin were significantly higher in individuals who carried the A allele of RETN single nucleotide polymorphism rs3219175 than in those who did not carry the allele. There was no significant interaction between the genotype and dexamethasone administration. No significant correlation was found between plasma levels of cortisol and resistin. Consistent with previous studies, the genotype of RETN rs3219175 was a strong determinant of resistin levels. The present study showed that oral administration of dexamethasone increases the protein and mRNA levels of resistin irrespective of the rs3219175 genotype.
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Dexametasona/farmacologia , Glucocorticoides/farmacologia , Resistina/metabolismo , Adulto , Alelos , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Resistina/genéticaRESUMO
The systemic inflammatory response observed during acute graft-versus-host disease (aGVHD) is driven by proinflammatory cytokines, a 'cytokine storm'. The function of plasmin in regulating the inflammatory response is not fully understood, and its role in the development of aGVHD remains unresolved. Here we show that plasmin is activated during the early phase of aGVHD in mice, and its activation correlated with aGVHD severity in humans. Pharmacological plasmin inhibition protected against aGVHD-associated lethality in mice. Mechanistically, plasmin inhibition impaired the infiltration of inflammatory cells, the release of membrane-associated proinflammatory cytokines including tumor necrosis factor-α (TNF-α) and Fas-ligand directly, or indirectly via matrix metalloproteinases (MMPs) and alters monocyte chemoattractant protein-1 (MCP-1) signaling. We propose that plasmin and potentially MMP-9 inhibition offers a novel therapeutic strategy to control the deadly cytokine storm in patients with aGVHD, thereby preventing tissue destruction.
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Fibrinolisina/antagonistas & inibidores , Doença Enxerto-Hospedeiro/prevenção & controle , Mediadores da Inflamação/antagonistas & inibidores , Metaloproteinase 9 da Matriz/metabolismo , Animais , Sequência de Bases , Transporte Biológico , Linhagem Celular , Primers do DNA , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Doença Enxerto-Hospedeiro/enzimologia , Doença Enxerto-Hospedeiro/mortalidade , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Índice de Gravidade de DoençaRESUMO
Monoclonal antibodies have become a general modality in therapeutic development. However, even with infinite binding affinity to an antigen, a conventional antibody is limited in that it can bind to the antigen only once, and this results in antigen-mediated antibody clearance when the a membrane-bound antigen is targeted, or in antibody-mediated antigen accumulation when a soluble antigen is targeted. Recently, a pH-dependent antigen-binding antibody that binds to an antigen in plasma at neutral pH and dissociates from the antigen in endosome at acidic pH has been reported to overcome this limitation and to reduce antigen-mediated antibody clearance and antibody-mediated antigen accumulation. A pH-dependent binding antibody against a soluble antigen can be further improved by Fc engineering to enhance the Fc receptor binding. Various approaches, including histidine-based engineering, direct cloning from immunized animals, and synthetic and combinatorial libraries, have been successfully applied to generate pH-dependent binding antibodies against various antigens. This review discusses the features, approaches, advantages, and challenges of developing a pH-dependent binding antibody as a novel therapeutic modality. This article is part of a Special Issue entitled: Recent advances in molecular engineering of antibody.
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Gravitational lensing due to the large-scale distribution of matter in the cosmos distorts the primordial cosmic microwave background (CMB) and thereby induces new, small-scale B-mode polarization. This signal carries detailed information about the distribution of all the gravitating matter between the observer and CMB last scattering surface. We report the first direct evidence for polarization lensing based on purely CMB information, from using the four-point correlations of even- and odd-parity E- and B-mode polarization mapped over â¼30 square degrees of the sky measured by the POLARBEAR experiment. These data were analyzed using a blind analysis framework and checked for spurious systematic contamination using null tests and simulations. Evidence for the signal of polarization lensing and lensing B modes is found at 4.2σ (stat+sys) significance. The amplitude of matter fluctuations is measured with a precision of 27%, and is found to be consistent with the Lambda cold dark matter cosmological model. This measurement demonstrates a new technique, capable of mapping all gravitating matter in the Universe, sensitive to the sum of neutrino masses, and essential for cleaning the lensing B-mode signal in searches for primordial gravitational waves.
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BACKGROUND: The Japan Geriatrics Society published a guideline on the decision-making process for health care for the elderly in June 2012, noting that withholding or withdrawing feeding tubes are treatment options that should be discussed during the decision-making process. Arguments against the guideline posit that the insertion of a percutaneous endoscopic gastrostomy (PEG) tube feeding may improve quality of life (QOL) for elderly adults and their relatives. OBJECTIVES: The aim of the present study was to explore (a) expected outcomes with PEG tube placement and (b) outcomes from PEG tube feeding in long-term care settings among elderly adults with advanced dementia in Japan. DESIGN: This study was conducted using a cross-sectional study design. SETTING: A total of 381 hospitals and 985 long-term care facilities provided sets of completed questionnaires. PARTICIPANTS: There were 1 199 hospital patients and 2 160 long-term care patients aged 65 years or older with PEG tube placement included in the analysis. MEASUREMENTS: The nurses or physicians at each hospital provided information on the level of dementia at the time of PEG tube placement and on the expected outcomes of PEG tube feeding for elderly hospital patients. The nurses or other direct care workers at each facility provided information on the level of dementia and outcomes from PEG tube feeding for the long-term care patients. RESULTS: In the hospital patient group, 62.9% of patients had advanced dementia. PEG tube feeding was expected to prolong survival for 51.1% of hospital patients with advanced dementia. Improved QOL was expected for 39.1% of them. In the long-term care patient group, 61.7% of patients had advanced dementia. The rate of patients enjoying their own lives was lower in long-term care patients who had advanced dementia (4.2%) than in the other patients (16.4%). Approximately 60% of relatives reported satisfaction with the QOL of the patients, both in the long-term care patients with advanced dementia and the other patients. CONCLUSION: Our results question the assumption that PEG tube feeding may improve QOL among elderly adults with advanced dementia. The national health policy should explore an approach to help patients, relatives, and practitioners make decisions about feeding options.
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Demência/complicações , Demência/terapia , Endoscopia/estatística & dados numéricos , Nutrição Enteral/estatística & dados numéricos , Gastrostomia/estatística & dados numéricos , Intubação Gastrointestinal/estatística & dados numéricos , Qualidade de Vida , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Tomada de Decisões , Demência/diagnóstico , Feminino , Avaliação Geriátrica , Geriatria/métodos , Humanos , Japão , Assistência de Longa Duração/métodos , Masculino , Estado Nutricional , Guias de Prática Clínica como Assunto , Reprodutibilidade dos Testes , Inquéritos e Questionários , Análise de Sobrevida , Resultado do TratamentoAssuntos
Edema/diagnóstico , Sinovite/diagnóstico , Idoso , Edema/tratamento farmacológico , Feminino , Doenças do Pé/diagnóstico , Doenças do Pé/tratamento farmacológico , Glucocorticoides/uso terapêutico , Humanos , Prednisolona/uso terapêutico , Sinovite/tratamento farmacológico , Resultado do TratamentoRESUMO
We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0σ and indication of the presence of a lensing B-mode signal at a significance of 2.3σ. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics.
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BACKGROUND: We previously reported that a humanized anti-factor IXa/X bispecific antibody, hBS23, mimics the function of FVIII even in the presence of FVIII inhibitors, and has preventive hemostatic activity against bleeding in an animal model of acquired hemophilia A. After further molecular engineering of hBS23, we recently identified an improved humanized bispecific antibody, ACE910, for clinical investigation. OBJECTIVES: To elucidate the in vivo hemostatic potency of ACE910 by examining its effect against ongoing bleeds, and to determine its pharmacokinetic parameters for discussion of its potency for prophylactic use. METHODS: A non-human primate model of acquired hemophilia A was established by injecting anti-primate FVIII neutralizing antibody. When bleeds emerged following an artificial bleed-inducing procedure, either ACE910 or recombinant porcine FVIII (rpoFVIII) was intravenously administered. rpoFVIII was additionally administered twice daily on the following 2 days. Bleeding symptoms were monitored for 3 days. A pharmacokinetic study and multiple-dosing simulations of ACE910 were also performed. RESULTS: A single bolus of 1 or 3 mg kg-1 ACE910 showed hemostatic activity comparable to that of 10 U kg-1 (twice daily) rpoFVIII against ongoing bleeds. The determined ACE910 pharmacokinetic parameters included a long half-life (3 weeks) and high subcutaneous bioavailability (nearly 100%). The simulation results based on pharmacokinetic parameters indicated that the above hemostatic level could be maintained with once-weekly subcutaneous administration of ACE910, suggesting the possibility of more effective prophylaxis. CONCLUSIONS: ACE910 may offer an alternative on-demand treatment option for patients with hemophilia A, as well as user-friendly and aggressive routine supplementation.
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BACKGROUND: We previously reported that a humanized anti-factor IXa/X bispecific antibody, hBS23, mimics the function of FVIII even in the presence of FVIII inhibitors, and has preventive hemostatic activity against bleeding in an animal model of acquired hemophilia A. After further molecular engineering of hBS23, we recently identified an improved humanized bispecific antibody, ACE910, for clinical investigation. OBJECTIVES: To elucidate the in vivo hemostatic potency of ACE910 by examining its effect against ongoing bleeds, and to determine its pharmacokinetic parameters for discussion of its potency for prophylactic use. METHODS: A nonhuman primate model of acquired hemophilia A was established by injecting anti-primate FVIII neutralizing antibody. When bleeds emerged following an artificial bleed-inducing procedure, either ACE910 or recombinant porcine FVIII (rpoFVIII) was intravenously administered. rpoFVIII was additionally administered twice daily on the following 2 days. Bleeding symptoms were monitored for 3 days. A pharmacokinetic study and multiple-dosing simulations of ACE910 were also performed. RESULTS: A single bolus of 1 or 3 mg kg⻹ ACE910 showed hemostatic activity comparable to that of 10 U kg⻹ (twice daily) rpoFVIII against ongoing bleeds. The determined ACE910 pharmacokinetic parameters included a long half-life (3 weeks) and high subcutaneous bioavailability (nearly 100%). The simulation results based on pharmacokinetic parameters indicated that the above hemostatic level could be maintained with once-weekly subcutaneous administration of ACE910, suggesting the possibility of more effective prophylaxis. CONCLUSIONS: ACE910 may offer an alternative on-demand treatment option for patients with hemophilia A, as well as user-friendly and aggressive routine supplementation.
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Anticorpos/imunologia , Fator IXa/imunologia , Fator X/imunologia , Hemofilia A/terapia , Hemostasia/imunologia , Animais , Células CHO , Cricetinae , Cricetulus , Reações Cruzadas , Modelos Animais de Doenças , Células HEK293 , Humanos , Macaca fascicularis , MasculinoRESUMO
Enhancing the effector function by optimizing the interaction between Fc and Fcγ receptor (FcγR) is a promising approach to enhance the potency of anticancer monoclonal antibodies (mAbs). To date, a variety of Fc engineering approaches to modulate the interaction have been reported, such as afucosylation in the heavy chain Fc region or symmetrically introducing amino acid substitutions into the region, and there is still room to improve FcγR binding and thermal stability of the CH2 domain with these approaches. Recently, we have reported that asymmetric Fc engineering, which introduces different substitutions into each Fc region of heavy chain, can further improve the FcγR binding while maintaining the thermal stability of the CH2 domain by fine-tuning the asymmetric interface between the Fc domain and FcγR. However, the structural mechanism by which the asymmetrically engineered Fc improved FcγR binding remained unclear. In order to elucidate the mechanism, we solved the crystal structure of a novel asymmetrically engineered Fc, asym-mAb23, in complex with FcγRIIIa. Asym-mAb23 has enhanced binding affinity for both FcγRIIIa and FcγRIIa at the highest level of previously reported Fc variants. The structural analysis reveals the features of the asymmetrically engineered Fc in comparison with symmetric Fc and how each asymmetrically introduced substitution contributes to the improved interaction between asym-mAb23 and FcγRIIIa. This crystal structure could be utilized to enable us to design a more potent asymmetric Fc.
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Anticorpos Monoclonais/imunologia , Afinidade de Anticorpos , Fragmentos Fc das Imunoglobulinas/ultraestrutura , Receptores de IgG/imunologia , Substituição de Aminoácidos/genética , Anticorpos Monoclonais/genética , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Cristalografia por Raios X , Humanos , Fragmentos Fc das Imunoglobulinas/química , Fragmentos Fc das Imunoglobulinas/imunologia , Ligação Proteica/genética , Ligação Proteica/imunologia , Engenharia de Proteínas , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologiaRESUMO
Antibody humanization is an essential technology for reducing the potential risk of immunogenicity associated with animal-derived antibodies and has been applied to a majority of the therapeutic antibodies on the market. For developing an antibody molecule as a pharmaceutical at the current biotechnology level, however, other properties also have to be considered in parallel with humanization in antibody generation and optimization. This section describes the critical properties of therapeutic antibodies that should be sufficiently qualified, including immunogenicity, binding affinity, physiochemical stability, expression in host cells and pharmacokinetics, and the basic methodologies of antibody engineering involved. By simultaneously optimizing the antibody molecule in the light of these properties, it should prove possible to shorten the research and development period necessary to identify a highly qualified clinical candidate and consequently accelerate the start of the clinical trial.