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1.
Viruses ; 13(2)2021 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-33572652

RESUMO

Rabies virus (RABV) causes fatal neurological encephalitis and results in approximately 6000 human death cases worldwide every year. The large (L) protein of RABV, possessing conserved domains, is considered as the target for detection. In this study, three monoclonal antibodies (mAbs), designated as 3F3, 3A6 and L-C, against L protein were generated by using the recombinant truncated L protein (aa 1431-1754) and the epitopes were also identified using a series of overlapping truncated polypeptides for testing the reactivity of mAbs with different RABV strains. The 1479EIFSIP1484, 1659RALSK1663 and 1724VFNSL1728 were identified as the minimal linear epitopes recognized by mAbs 3F3, 3A6 and L-C, respectively. Amino acid alignment showed epitope 1724VFNSL1728 recognized by mAb L-C is completely conserved among RABV strains, indicating that mAb L-C could be used to detect all of the RABV strains. Epitope 1479EIFSIP1484 is highly conserved among RABV strains except for a P1484S substitution in a China I sub-lineage strain of Asian lineage, which eliminated the reactivity of the epitope with mAb 3F3. However, the epitope 1659RALSK1663 was only completely conserved in the Africa-2 and Indian lineages, and a single A1660T substitution, mainly appeared in strains of the China I belonging to Asian lineage and a Cosmopolitan lineage strain, still retained the reactivity of the epitope with mAb 3A6. While both A1660T and K1663R substitutions in a China I lineage strain, single K1663R/Q substitution in some China II strains of Asian lineage and some Arctic-like lineage strains and R1659Q mutation in a strain of Africa-3 lineage eliminated the reactivity of the epitope with mAb 3A6, suggesting mAb 3A6 could be used for differentiation of variable epitopes of some strains in different lineages. Thus, variability and conservation of the three epitopes of L protein showed the reactive difference of mAbs among RABV strains of different lineages. These results may facilitate future studies in development of detection methods for RABV infection, the structure and function of RABV L protein.


Assuntos
Anticorpos Monoclonais/análise , RNA Polimerases Dirigidas por DNA/imunologia , Epitopos/imunologia , Vírus da Raiva/imunologia , Raiva/virologia , Proteínas Virais/imunologia , Sequência de Aminoácidos , Anticorpos Monoclonais/imunologia , RNA Polimerases Dirigidas por DNA/química , RNA Polimerases Dirigidas por DNA/genética , Mapeamento de Epitopos , Epitopos/química , Epitopos/genética , Humanos , Filogenia , Vírus da Raiva/química , Vírus da Raiva/classificação , Vírus da Raiva/genética , Alinhamento de Sequência , Proteínas Virais/química , Proteínas Virais/genética
2.
J Chromatogr A ; 1639: 461922, 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33540183

RESUMO

A peak-tracking algorithm was developed for use in comprehensive two-dimensional liquid chromatography coupled to mass spectrometry. Chromatographic peaks were tracked across two different chromatograms, utilizing the available spectral information, the statistical moments of the peaks and the relative retention times in both dimensions. The algorithm consists of three branches. In the pre-processing branch, system peaks are removed based on mass spectra compared to low intensity regions and search windows are applied, relative to the retention times in each dimension, to reduce the required computational power by elimination unlikely pairs. In the comparison branch, similarity between the spectral information and statistical moments of peaks within the search windows is calculated. Lastly, in the evaluation branch extracted-ion-current chromatograms are utilized to assess the validity of the pairing results. The algorithm was applied to peptide retention data recorded under varying chromatographic conditions for use in retention modelling as part of method optimization tools. Moreover, the algorithm was applied to complex peptide mixtures obtained from enzymatic digestion of monoclonal antibodies. The algorithm yielded no false positives. However, due to limitations in the peak-detection algorithm, cross-pairing within the same peaks occurred and six trace compounds remained falsely unpaired.


Assuntos
Algoritmos , Anticorpos Monoclonais/análise , Cromatografia Líquida/métodos , Peptídeos/análise , Espectrometria de Massas/métodos , Reconhecimento Automatizado de Padrão , Padrões de Referência
3.
J Chromatogr A ; 1626: 461350, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797830

RESUMO

In ionexchange chromatography, the pH gradient mode becomes more and more popular today for the analysis of therapeutic proteins as this mode can provide higher or alternative selectivity to the commonly used salt gradient mode. Ideally, a linear pH response is expected when performing linear gradients. However up to now, only a very few buffer systems have been developed and are commercially available which can perform nearly linear pH responses when flowing through a given column. It is also known that a selected buffer system (mobile phase) can work well on one column but can fail on other column. The goal of this study was to practically evaluate the effects that ionexchange columns (weak and strong exchangers) might have on effluent pH, when performing linear pH gradient separations of therapeutic monoclonal antibodies. To attain this objective, the pH was monitored on-line at the column outlet using a specific setup. To make comprehensive observations of the phenomenon, four different mobile phase conditions and five cation exchange columns (weak and strong exchangers) were employed. The obtained pH responses were systematically compared to responses measured in the absence of the columns. From this work, it has become clear that both the column and mobile phase can have significant effects on pH gradient chromatography and that their combination must be considered when developing a new method. Phase systems (column + mobile phase) providing linear pH responses are indeed the most suitable for separating mAbs with different isoelectric points and, with them, it is possible to elute mAbs across wide retention time ranges and with high selectivity.


Assuntos
Cromatografia por Troca Iônica/métodos , Anticorpos Monoclonais/análise , Cátions/química , Ácido Cítrico/química , Concentração de Íons de Hidrogênio , Troca Iônica , Força Próton-Motriz , Hidróxido de Sódio/química , Taurina/análogos & derivados , Taurina/química
4.
Biosensors (Basel) ; 10(9)2020 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-32847008

RESUMO

Cytokines are a family of proteins which play a major role in the regulation of the immune system and the development of several diseases, from rheumatoid arthritis to cancer and, more recently, COVID-19. Therefore, many efforts are currently being developed to improve therapy and diagnosis, as well as to produce inhibitory drugs and biosensors for a rapid, minimally invasive, and effective detection. In this regard, even more efficient cytokine receptors are under investigation. In this paper we analyze a set of IL-6 cytokine receptors, investigating their topological features by means of a theoretical approach. Our results suggest a topological indicator that may help in the identification of those receptors having the highest complementarity with the protein, a feature expected to ensure a stable binding. Furthermore, we propose and discuss the use of these receptors in an idealized experimental setup.


Assuntos
Técnicas Biossensoriais/métodos , Interleucina-6/análise , Receptores de Interleucina-6/análise , Anticorpos Monoclonais/análise , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais Humanizados/química , Anticorpos Monoclonais Humanizados/imunologia , Aptâmeros de Nucleotídeos/química , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Humanos , Fragmentos Fab das Imunoglobulinas/análise , Fragmentos Fab das Imunoglobulinas/imunologia , Interleucina-6/imunologia , Limite de Detecção , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , Receptores de Interleucina-6/imunologia
5.
Nature ; 584(7821): 450-456, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32698192

RESUMO

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic continues, with devasting consequences for human lives and the global economy1,2. The discovery and development of virus-neutralizing monoclonal antibodies could be one approach to treat or prevent infection by this coronavirus. Here we report the isolation of sixty-one SARS-CoV-2-neutralizing monoclonal antibodies from five patients infected with SARS-CoV-2 and admitted to hospital with severe coronavirus disease 2019 (COVID-19). Among these are nineteen antibodies that potently neutralized authentic SARS-CoV-2 in vitro, nine of which exhibited very high potency, with 50% virus-inhibitory concentrations of 0.7 to 9 ng ml-1. Epitope mapping showed that this collection of nineteen antibodies was about equally divided between those directed against the receptor-binding domain (RBD) and those directed against the N-terminal domain (NTD), indicating that both of these regions at the top of the viral spike are immunogenic. In addition, two other powerful neutralizing antibodies recognized quaternary epitopes that overlap with the domains at the top of the spike. Cryo-electron microscopy reconstructions of one antibody that targets the RBD, a second that targets the NTD, and a third that bridges two separate RBDs showed that the antibodies recognize the closed, 'all RBD-down' conformation of the spike. Several of these monoclonal antibodies are promising candidates for clinical development as potential therapeutic and/or prophylactic agents against SARS-CoV-2.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Epitopos de Linfócito B/imunologia , Pneumonia Viral/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , Anticorpos Monoclonais/análise , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/ultraestrutura , Anticorpos Neutralizantes/análise , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/ultraestrutura , Anticorpos Antivirais/análise , Anticorpos Antivirais/química , Anticorpos Antivirais/ultraestrutura , Betacoronavirus/química , Betacoronavirus/ultraestrutura , Infecções por Coronavirus/prevenção & controle , Microscopia Crioeletrônica , Modelos Animais de Doenças , Mapeamento de Epitopos , Epitopos de Linfócito B/química , Epitopos de Linfócito B/ultraestrutura , Feminino , Humanos , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/imunologia , Fragmentos Fab das Imunoglobulinas/ultraestrutura , Pulmão/patologia , Pulmão/virologia , Masculino , Mesocricetus , Modelos Moleculares , Testes de Neutralização , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Glicoproteína da Espícula de Coronavírus/ultraestrutura
6.
Nature ; 584(7821): 437-442, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32555388

RESUMO

During the coronavirus disease-2019 (COVID-19) pandemic, severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) has led to the infection of millions of people and has claimed hundreds of thousands of lives. The entry of the virus into cells depends on the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2. Although there is currently no vaccine, it is likely that antibodies will be essential for protection. However, little is known about the human antibody response to SARS-CoV-21-5. Here we report on 149 COVID-19-convalescent individuals. Plasma samples collected an average of 39 days after the onset of symptoms had variable half-maximal pseudovirus neutralizing titres; titres were less than 50 in 33% of samples, below 1,000 in 79% of samples and only 1% of samples had titres above 5,000. Antibody sequencing revealed the expansion of clones of RBD-specific memory B cells that expressed closely related antibodies in different individuals. Despite low plasma titres, antibodies to three distinct epitopes on the RBD neutralized the virus with half-maximal inhibitory concentrations (IC50 values) as low as 2 ng ml-1. In conclusion, most convalescent plasma samples obtained from individuals who recover from COVID-19 do not contain high levels of neutralizing activity. Nevertheless, rare but recurring RBD-specific antibodies with potent antiviral activity were found in all individuals tested, suggesting that a vaccine designed to elicit such antibodies could be broadly effective.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Pneumonia Viral/imunologia , Adolescente , Adulto , Idoso , Anticorpos Monoclonais/análise , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/análise , Anticorpos Antivirais/análise , Especificidade de Anticorpos , Infecções por Coronavirus/prevenção & controle , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Pandemias , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/imunologia , Adulto Jovem
7.
J Acupunct Meridian Stud ; 13(3): 110-115, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32437979

RESUMO

BACKGROUND: The primo vascular system (PVS) has been difficult to detect due to its small diameter and translucent features of the threadlike network. Thus, contrast-enhancing dyes including Alcian blue, Trypan blue and Janus green B had to be used for finding and taking out PVS from rat and mouse. OBJECTIVE: Generation of monoclonal antibodies (mAbs) against PVS of rat was intended to use as a detector for PVS and a biological tool for functional study of PVS. MATERIALS AND METHODS: Primo vessel (PV) and Primo node (PN) were isolated from organ surfaces of rat and then their proteins were isolated and injected into mouse as an immunogen. The classical traditional method was applied for production of mAbs against PVS. The various techniques, such as cell fusion, screening of hybridoma, ELISA, Western blotting (WB), immunofluorescence microscopy (IF), and limiting dilution, were used to generate mAbs against PVS. RESULTS: Among 16 mAbs generated, 4 representative mAbs were characterized with their specificities in ELISA, WB, and IF. α-rPVS-m1-1 and α-rPVS-m4-6 had strong binding affinities to PVS in both ELISA and WB but did not show specificities in IF at all. On the contrary, α-rPVS-m3-2 and α-rPVS-m3-4 almost did not respond in WB but had strong binding affinities in ELISA and specificities in IF. Two mAbs stained predominantly at extra cellular matrix and cell membrane of PVS of rat in IF, and they were able to discriminate PVS from blood vessel (BV) and lymphatic vessel (LV). CONCLUSIONS: 4 representative mAbs against PVS of rat were characterized by ELISA, WB, and IF. α-rPVS-m3-2 and α-rPVS-m3-4, which had strong specificities in IF, can be used as a tool in discriminating PVS from other similar tissues and in elucidate biological function of PVS.


Assuntos
Anticorpos Monoclonais/análise , Vasos Linfáticos/química , Meridianos , Azul Alciano/química , Animais , Masculino , Camundongos , Ratos , Ratos Sprague-Dawley , Coloração e Rotulagem
8.
Transfusion ; 60(5): 1060-1068, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32369193

RESUMO

BACKGROUND: Anti-red blood cell (RBC) alloantibodies consisting of only the immunoglobulin G (IgG) 4 subtype are typically considered clinically insignificant. A US Food and Drug Administration-approved monoclonal anti-human globulin (16H8) is nonreactive with IgG4, which has been considered a benefit to avoid testing interference from IgG4. However, 16H8 also does not recognize two natural IgG3 variants (IgG3-03 and IgG3-13). Thus, 16H8 may miss clinically significant alloantibodies in some settings. STUDY DESIGN AND METHODS: Novel mouse anti-human IgG hybridomas were generated and screened for reactivity with 32 human variants of anti-KEL1 across different IgG subtypes, as well as mutants to allow epitope mapping. Anti-IgG reactivity was determined using KEL1+ RBCs bound by each IgG variant as targets. Binding of anti-IgG was determined by flow cytometry. RESULTS: 16H8 recognized an epitope involving amino acid 419, which is glutamate in IgG4, IgG3-03, and IgG3-13, explaining the lack of 16H8 reactivity with these subtypes/isoallotypes. A new monoclonal antibody (PUMA8) was isolated that, like 16H8, was nonreactive with IgG4 but without blind spots for known variants of IgG1, IgG2, or IgG3. PUMA8 recognized an epitope containing arginine at position 355, which is glutamine in IgG4. However, a recently described new IgG4 variant with an arginine at position 355 results in PUMA8 reactivity. CONCLUSION: PUMA8 represents an alternative to 16H8 that avoids IgG4 but without blind spots for IgG3 variants. However, PUMA8 reacts with one recently described IgG4 variant. In addition to relevance to immunohematology, these studies highlight the importance of patient variation with regards to assay performance in an era of personalized medicine.


Assuntos
Anticorpos Monoclonais/análise , Anticorpos Monoclonais/imunologia , Imunoglobulina G/imunologia , Imunoglobulinas/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/metabolismo , Células CHO , Cricetinae , Cricetulus , Epitopos/química , Epitopos/imunologia , Epitopos/metabolismo , Eritrócitos/imunologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/química , Imunoglobulina G/metabolismo , Imunoglobulinas/química , Imunoglobulinas/metabolismo , Testes Imunológicos , Isoanticorpos/análise , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Ligação Proteica , Análise de Sequência de Proteína
9.
Arch Virol ; 165(7): 1551-1556, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32356186

RESUMO

Chinese sacbrood disease (CSBD) is a highly pathogenic infectious disease in bees that is caused by Chinese sacbrood virus (CSBV). Although several molecular detection methods have been developed for CSBV, there are no commercially available enzyme-linked immunosorbent assay (ELISA) kits. We therefore developed a sandwich ELISA to detect CSBV antigens. To this end, monoclonal antibodies were produced using VP2 as an immunogen and subsequently characterized. Hybridomas were screened for the secretion of immunoglobulin G (IgG). Using an unlabeled monoclonal antibody (mAb) for coating and a horseradish peroxidase (HRP)-labeled mAb for detection, a CSBV sandwich ELISA method was established. This method showed specificity for CSBV and did not show cross-reactivity with other bee viruses. The detection limit of the sandwich ELISA was 3.675 × 104 copies/µL. Sixty bee larvae were tested using our sandwich ELISA method, and the presence of CSBV was verified by reverse transcription polymerase chain reaction (RT-PCR). The total coincidence rate was 90%. Thus, a sandwich ELISA method with high specificity and accuracy and a detection limit of 3.675 × 104 copies/µL has been successfully developed and can be used for the clinical detection of CSBV. This method will support rapid diagnosis, real-time monitoring, and early warning of CSBD.


Assuntos
Abelhas/virologia , Ensaio de Imunoadsorção Enzimática/métodos , Vírus de RNA/isolamento & purificação , Animais , Anticorpos Monoclonais/análise , Anticorpos Monoclonais/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática/instrumentação , Imunoglobulina G/análise , Imunoglobulina G/imunologia , Larva , Limite de Detecção , Vírus de RNA/imunologia
10.
J Food Sci ; 85(6): 1681-1688, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32418205

RESUMO

Valnemulin (VAL) and tiamulin (TIA) are pleuromutilin antibiotics used primarily for treating bacterial infections in swine or other food animals. Furthermore, VAL and TIA are also employed as feed additives to promote animal growth. However, the illegal use of VAL and TIA could cause a series of hazards to consumers. Here, VAL was designed to be conjugated with bovine serum protein to prepare immunogen. A highly sensitive monoclonal antibody that recognized both VAL and TIA has been successfully produced. Moreover, an immunochromatographic strip assay for rapidly screening VAL and TIA in porcine liver was established with visual detection limits (cutoff values) of 50 and 25 ng/g, respectively. The IC50 values calculated from the equation of the standard curve were 6.06 and 3.45 ng/g and the limits of detection were 0.96 and 0.29 ng/g for VAL and TIA. According to the recovery experiment results, the test strip exhibited acceptable accuracy and precision. Generally, the proposed strip provided a practical tool for the detection of VAL and TIA. PRACTICAL APPLICATION: We produced a highly sensitive monoclonal antibody and developed an immunoassay strip for simultaneously monitoring TIA and VAL. Additionally it was preliminarily confirmed that the rapid detection tool was suitable for screening TIA and VAL in porcine liver.


Assuntos
Antibacterianos/análise , Anticorpos Monoclonais/análise , Imunoensaio/métodos , Fígado/química , Animais , Bovinos , Diterpenos/análise , Contaminação de Alimentos/análise , Limite de Detecção , Suínos
11.
J Med Chem ; 63(10): 5360-5366, 2020 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-32374601

RESUMO

Noninvasive evaluation of tertiary structures is fundamental to the research, development, and use of the biologics. However, few methodologies are currently available for evaluating large molecular weight (MW) biologics, such as therapeutic monoclonal antibodies (mAbs; 150 kDa). Here, we have newly developed a 15N direct detection nuclear magnetic resonance (NMR) technique, the 15N direct detection CRINEPT, which allows the observation of the main chain amide resonances of a nondeuterated protein with MW 150 kDa. The technique not only substantially expands the range of proteins applicable to solution NMR studies but also allows the noninvasive structural analyses of intact mAbs in a wide range of temperature and solvent conditions. As a proof of principle, we successfully acquired the 15N-detected CRINEPT spectra of an intact mAb in its formulated solution at 4 °C. The technique was able to discriminate heterogeneous galactosylation states, demonstrating the benefit of high resolution of the 15N direct detection.


Assuntos
Anticorpos Monoclonais/análise , Anticorpos Monoclonais/química , Composição de Medicamentos/métodos , Espectroscopia de Ressonância Magnética/métodos , Mapeamento de Peptídeos/métodos , Anticorpos Monoclonais/metabolismo , Armazenamento de Medicamentos/métodos , Células HEK293 , Humanos , Isótopos de Nitrogênio/química , Isótopos de Nitrogênio/metabolismo , Estrutura Secundária de Proteína
12.
An Bras Dermatol ; 95(3): 278-282, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32299738

RESUMO

BACKGROUND: The hair follicle is a unique structure, one of the most dynamic structures in mammalians, which can reproduce in every new cycle all the mechanism involved in its fetal development. Although a lot of research has been made about the human hair follicle much less has been discovered about the importance of the cytokeratins (CKs) in its development. OBJECTIVE: Study the immunohistochemical pattern of epithelial CKs during human hair follicle development. METHODS: We performed an immunohistochemical study using fresh post-mortem skin biopsies of human fetuses between 4 and 25 weeks of gestational age to study the expression of cytokeratins (CKs): CK1, CK10, CK13, CK14, CK16 and CK20 during human hair follicle fetal development. STUDY LIMITATIONS: Restrospective study with a good number of makers but with a small population. RESULTS/CONCLUSION: We found that, the CKs were expressed in an intermediate time during follicular development. The epithelial CKs (CK1, CK14, CK10, CK13) and the epithelial CKs with a proliferative character such as CK16 were expressed first, as markers of cellular maturation and follicular keratinization. At a later phase, CK20 was expressed in more developed primitive hair follicles as previously discussed in literature.


Assuntos
Folículo Piloso/citologia , Folículo Piloso/crescimento & desenvolvimento , Queratinas Específicas do Cabelo/análise , Fatores Etários , Anticorpos Monoclonais/análise , Desenvolvimento Fetal , Idade Gestacional , Humanos , Imuno-Histoquímica , Estudos Retrospectivos
13.
Einstein (Sao Paulo) ; 18: eAO5105, 2020.
Artigo em Inglês, Português | MEDLINE | ID: mdl-32159607

RESUMO

OBJECTIVE: To evaluate the density of anti-galectin-3-immunostained cells, collagen percentage, mast cell density and presence of pathological processes in intestinal muscle biopsies of patients. METHODS: Thirty-five patients who underwent intestinal biopsy were selected from 1997 to 2015. Patients were divided into three groups: chagasic patients with mucosal lesion (n=13), chagasic patients with intact mucosa (n=12) and non-chagasic patients with no mucosal lesion (n=10). Histological processing of the biopsied fragments and immunohistochemistry for galectin-3 were performed. Additional sections were stained with hematoxylin and eosin to evaluate the general pathological processes, picrosirius for evaluation of collagen and toluidine blue to evaluate the mast cell density. RESULTS: Patients of mucosal lesion group had a significantly higher frequency of ganglionitis and myositis when compared to the chagasic patients with intact mucosa and non-chagasic group. The density of anti-galectin-3-immunostained cells was significantly higher in the chagasic patients with intact mucosa group when compared to the non-chagasic group. The group of chagasic patients with intact mucosa presented a higher percentage of collagen in relation to the patients with mucosal lesion and to the non-chagasic group, with a significant difference. There was no significant difference in mast cell density among the three groups. CONCLUSION: The higher density of anti-galectin-3-immunostained cells in patients in the chagasic patients with intact mucosa group suggested the need for greater attention in clinical evaluation of these patients, since this protein is associated with neoplastic transformation and progression.


Assuntos
Anticorpos Monoclonais/análise , Doença de Chagas/patologia , Colonoscopia/métodos , Galectina 3/análise , Mucosa Intestinal/patologia , Megacolo/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Biópsia , Estudos de Casos e Controles , Contagem de Células , Colágeno/análise , Feminino , Fibrose , Galectina 3/imunologia , Humanos , Imuno-Histoquímica , Masculino , Mastócitos/patologia , Pessoa de Meia-Idade , Miosite/patologia , Estudos Retrospectivos , Estatísticas não Paramétricas
14.
PLoS One ; 15(3): e0229080, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32196507

RESUMO

Therapeutic monoclonal antibodies have the potential to work as biological therapeutics. OKT3, Herceptin, Keytruda and others have positively impacted healthcare. Antibodies evolved naturally to provide high specificity and high affinity once mature. These characteristics can make them useful as therapeutics. However, we may be missing characteristics that are not obvious. We present a means of measuring antibodies in an unbiased manner that may highlight therapeutic activity. We propose using a microarray of random peptides to assess antibody properties. We tested twenty-four different commercial antibodies to gain some perspective about how much information can be derived from binding antibodies to random peptide libraries. Some monoclonals preferred to bind shorter peptides, some longer, some preferred motifs closer to the C-term, some nearer the N-term. We tested some antibodies with clinical activity but whose function was blinded to us at the time. We were provided with twenty-one different monoclonal antibodies, thirteen mouse and eight human IgM. These antibodies produced a variety of binding patterns on the random peptide arrays. When unblinded, the antibodies with polyspecific binding were the ones with the greatest therapeutic activity. The protein target to these therapeutic monoclonals is still unknown but using common sequence motifs from the peptides we predicted several human and mouse proteins. The same five highest proteins appeared in both mouse and human lists.


Assuntos
Anticorpos Monoclonais/análise , Mapeamento de Epitopos/métodos , Biblioteca de Peptídeos , Análise Serial de Proteínas , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Monoclonais/metabolismo , Especificidade de Anticorpos , Ensaios de Triagem em Larga Escala/métodos , Humanos , Imunoglobulina M/análise , Imunoglobulina M/metabolismo , Camundongos , Peptídeos/química , Peptídeos/imunologia , Peptídeos/metabolismo , Análise Serial de Proteínas/métodos , Ligação Proteica , Proteoma/análise
15.
Artigo em Inglês | MEDLINE | ID: mdl-32069133

RESUMO

CD271 is a common receptor for all neurotrophins that is localized to neurons, endothelial cells, and the basal layer of the epithelium in normal tissue. Recently, we and others reported that CD271 plays essential roles in the development of squamous cell carcinoma, especially in tumor-initiating cells. Since little is known about how CD271 regulates cancer cell initiation and proliferation, antibodies that recognize different domains of CD271 are needed to enable investigation. Therefore, this study aimed to develop an antihuman CD271 antibody by immunizing mice with a CD271 antigen produced by a baculovirus. The antibody was named hCD271mAb#13, and it recognized cysteine-rich domain 1 with a higher affinity than the commercially available antibody ME20.4. We determined that hCD271mAb#13 is suitable for flow cytometry, Western blotting, immunocytochemistry, and immunohistochemistry of formalin-fixed paraffin-embedded tissue. Use of hCD271mAb#13 for CD271 labeling could enable detailed analyses of cancer cell regulation and other biological processes.


Assuntos
Adapaleno/imunologia , Anticorpos Monoclonais/análise , Anticorpos Monoclonais/imunologia , Cisteína/química , Cisteína/imunologia , Proteínas do Tecido Nervoso/imunologia , Receptores de Fator de Crescimento Neural/imunologia , Animais , Carcinoma de Células Escamosas , Imuno-Histoquímica , Camundongos , Células-Tronco Neoplásicas , Domínios Proteicos/imunologia , RNA Interferente Pequeno
16.
Sci Rep ; 10(1): 2509, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-32054922

RESUMO

NJ001 is a monoclonal antibody that can specifically recognize the SP70 antigen on lung adenocarcinoma cells. The goal of this study was to explore its utility in targeted imaging. Subcutaneous xenograft and orthotopic lung tumor implantation BALB/c mouse models were established. Near-infrared fluorescent CF750-labeled NJ001 was injected into two tumor mouse models. Mice that received orthotopic lung tumor implantation were also injected with NJ001-conjugated nanomagnetic beads intravenously, and then underwent micro-CT scanning. Meanwhile, mice with lung tumor were intravenously injected with normal saline and bare nanomagnetic beads as a control. Fluorescence could be monitored in the mice detected by anti-SP70 fluorescence imaging, which was consistent with tumor burden. Signal intensities detected with SP70-targeted micro-CT scans were greater than those in control mice. More importantly, orthotopic tumor lesions could be found on the fourth week with SP70-targeted imaging, which was 2 weeks earlier than detection in the control. Our results suggest that SP70 is a promising target for molecular imaging, and molecularly targeted imaging with an NJ001-labeled probe could be applied for the early detection of lung adenocarcinoma.


Assuntos
Adenocarcinoma de Pulmão/diagnóstico por imagem , Anticorpos Monoclonais/análise , Neoplasias Pulmonares/diagnóstico por imagem , Animais , Biomarcadores Tumorais/análise , Linhagem Celular Tumoral , Detecção Precoce de Câncer , Corantes Fluorescentes/análise , Humanos , Imunoconjugados/análise , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Imagem Molecular , Imagem Óptica
17.
J Neuropathol Exp Neurol ; 79(4): 407-418, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32106300

RESUMO

Human neurodegenerative diseases can be characterized as disorders of protein aggregation. As a key player in cellular autophagy and the ubiquitin proteasome system, p62 may represent an effective immunohistochemical target, as well as mechanistic operator, across neurodegenerative proteinopathies. In this study, 2 novel mouse-derived monoclonal antibodies 5G3 and 2A5 raised against residues 360-380 of human p62/sequestosome-1 were characterized via immunohistochemical application upon human tissues derived from cases of C9orf72-expansion spectrum diseases, Alzheimer disease, progressive supranuclear palsy, Lewy body disease, and multiple system atrophy. 5G3 and 2A5 reliably highlighted neuronal dipeptide repeat, tau, and α-synuclein inclusions in a distribution similar to a polyclonal antibody to p62, phospho-tau antibodies 7F2 and AT8, and phospho-α-synuclein antibody 81A. However, antibodies 5G3 and 2A5 consistently stained less neuropil structures, such as tau neuropil threads and Lewy neurites, while 2A5 marked fewer glial inclusions in progressive supranuclear palsy. Both 5G3 and 2A5 revealed incidental astrocytic tau immunoreactivity in cases of Alzheimer disease and Lewy body disease with resolution superior to 7F2. Through their unique ability to highlight specific types of pathological deposits in neurodegenerative brain tissue, these novel monoclonal p62 antibodies may provide utility in both research and diagnostic efforts.


Assuntos
Anticorpos Monoclonais/análise , Anticorpos Monoclonais/imunologia , Doenças Neurodegenerativas/imunologia , Doenças Neurodegenerativas/patologia , Proteína Sequestossoma-1/análise , Proteína Sequestossoma-1/imunologia , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Monoclonais/administração & dosagem , Astrócitos/imunologia , Células Cultivadas , Feminino , Humanos , Imuno-Histoquímica , Corpos de Inclusão/imunologia , Masculino , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Proteína Sequestossoma-1/administração & dosagem , alfa-Sinucleína/imunologia , Proteínas tau/imunologia
18.
Monoclon Antib Immunodiagn Immunother ; 39(1): 17-22, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31934820

RESUMO

Podoplanin (PDPN) is a small mucin-type transmembrane glycoprotein, which was first discovered in podocytes of the kidney. PDPN is a specific lymphatic endothelial marker and is also known as T1alpha, a marker of lung type I alveolar cells, or Aggrus, a platelet aggregation-inducing factor. PDPN possesses three platelet aggregation-stimulating (PLAG) domains and PLAG-like domains (PLDs), which bind to C-type lectin-like receptor-2. Previously, we developed a novel anti-whale PDPN (wPDPN) monoclonal antibody (mAb) PMab-237 using the Cell-Based Immunization and Screening (CBIS) method and the RIEDL tag of Arg-Ile-Glu-Asp-Leu sequence. PMab-237 detected wPDPN by flow cytometry, western blot, and immunohistochemical analyses. However, the specific binding epitope of PMab-237 for wPDPN remains unknown. In this study, deletion mutants and point mutants of wPDPN with N-terminal RIEDL tag were produced to analyze the PMab-237 epitope using flow cytometry. The analysis of deletion mutants showed that the N-terminus of the PMab-237 epitope exists between the 80th amino acid (AA) and the 85th AA of wPDPN. In addition, the analysis of point mutants demonstrated that the critical epitope of PMab-237 includes Leu82 and Thr84 of wPDPN, indicating that the PMab-237 epitope is located in the PLD of wPDPN.


Assuntos
Anticorpos Monoclonais/análise , Anticorpos Monoclonais/imunologia , Epitopos/análise , Epitopos/imunologia , Glicoproteínas de Membrana/imunologia , Animais , Mapeamento de Epitopos , Citometria de Fluxo , Mutação Puntual , Deleção de Sequência , Baleias
19.
Proc Natl Acad Sci U S A ; 117(6): 2767-2769, 2020 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-31988118

RESUMO

While single-cell sequencing technologies have revealed tissue heterogeneity, resolving mixed cellular libraries into cellular clones is essential for many pooled screens and clonal lineage tracing. Fluorescent proteins are limited in number, while DNA barcodes can only be read after cell lysis. To overcome these limitations, we used influenza virus hemagglutinins to engineer a genetically encoded cell-surface protein barcoding system. Using antibodies paired to hemagglutinins carrying combinations of escape mutations, we developed an exponential protein barcoding system which can label 128 clones using seven antibodies. This study provides a proof of principle for a strategy to create protein-level cell barcodes that can be used in vivo in mice to track clonal populations.


Assuntos
Anticorpos Monoclonais/análise , Rastreamento de Células/métodos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/análise , Animais , Rastreamento de Células/instrumentação , Feminino , Citometria de Fluxo/métodos , Células HEK293 , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Humanos , Melanoma/química , Melanoma/genética , Melanoma/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Orthomyxoviridae/química , Orthomyxoviridae/genética , Orthomyxoviridae/metabolismo
20.
J Pharm Biomed Anal ; 179: 112920, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31706629

RESUMO

In the last two decades, plants became an interesting alternative for the production of recombinant proteins for human therapy and several antibodies expressed in plants have reached the clinical development stage. Plants are capable of post-translational modifications (PTMs) necessary for protein activity and pharmacokinetics, such as glycosylation. However, there are important kingdom-specific modifications that have to be considered when expressing recombinant proteins. Therefore, there is a need for efficient analytical methods for deep protein characterization starting from the expression platform design until the product approval to guarantee product authenticity, quality and efficacy. Literature lacks of reviews dealing with plant-derived proteins purification and characterization by chromatographic methods, thus the focus of the present review is on this topic for the most representative biotechnological drugs i.e. monoclonal antibodies (mAbs). In the first part, a comprehensive discussion of the methods applied in dowstream processes (extraction and clarification) and a detailed overview of the chromatographic techniques useful for the purification of plant-made mAbs are reported. Among purification techniques, Protein A affinity chromatography, ion-exchange chromatography, hydrophobic interaction chromatography, hydrophobic charge induction chromatography or mixed mode chromatography are described. In the second part, we will discuss analytical platforms based on chromatographic techniques (reverse phase, size exclusion chromatography, ion-exchange chromatography, hydrophilic interaction liquid chromatography) coupled with different detection systems (UV, Fluorescence, MS) used at protein, peptide and glycan level to characterize plant-made mAbs with their unique features.


Assuntos
Anticorpos Monoclonais/análise , Cromatografia/métodos , Planticorpos/análise , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/isolamento & purificação , Glicosilação , Humanos , Interações Hidrofóbicas e Hidrofílicas , Planticorpos/química , Planticorpos/isolamento & purificação , Processamento de Proteína Pós-Traducional
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