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2.
STAR Protoc ; 5(1): 102815, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38180832

RESUMO

RNA 5-methylcytosine (m5C) modification critically impacts many biological processes. Here, we provide a protocol to analyze the role of various metabolites in impacting global RNA m5C levels in cultured cells by dot blot. We describe steps for treating cultured cells with various metabolites; extracting, quantifying, and denaturing RNA samples; and performing dot blot to detect global RNA m5C levels in cultured cells. We then detail procedures to verify the input loading by methylene blue staining and quantify using ImageJ. For complete details on the use and execution of this protocol, please refer to Chen et al.1.


Assuntos
5-Metilcitosina , RNA , Immunoblotting , RNA/genética , Coloração e Rotulagem
3.
STAR Protoc ; 5(1): 102857, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38285737

RESUMO

Dot-blot analysis is a technique that allows for fast and convenient detection and identification of nucleic acids and proteins. Here, we provide a guide for nucleic acid isolation from eukaryotic cells and sample processing to detect RNA/DNA hybrids. We then provide detailed steps to quantify dot signal intensity. This protocol can be adapted for screening conditions that result in the accumulation of R-loops. For complete details on the use and execution of this protocol, please refer to Smith et al.1.


Assuntos
Células Eucarióticas , Estruturas R-Loop , Immunoblotting , RNA
4.
Methods Mol Biol ; 2752: 201-214, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38194036

RESUMO

In this new era of precision medicine, characterization of single-cell subpopulations to better understand disease etiology is paramount. It is thus an opportune time to explore techniques that allow molecular analysis of single cells and to better understand the basis of pathogenesis of diseases like cancer. Single-cell western blotting is one such method that allows analysis of single cells at the protein level. In contrast to traditional western blotting, which relies heavily on bulk analysis of lysates generated from tissues and is often indicative of the population average, this technique allows analysis of lysates from single-cell subpopulations thereby providing a glimpse into cell heterogeneity. The method entails the use of a chip containing 30 µm thick photoactivated polyacrylamide gel spotted with nearly 6400 microwells. Single cells loaded on the chip are captured in the microwells by passive gravity and are then lysed and electrophoresed using the MILO™ single-cell western platform. This method forgoes the use of transfer of proteins on a PVDF and a nitrocellulose membrane, as performed in traditional western blotting, and all other steps including probing of primary and fluorescent secondary antibodies against the protein of interest are performed directly on the chip. The proteins of interest can then be visualized by scanning a chip with the use of a microarray scanner. The entire procedure can be performed in as less as 4-6 h, and thus this method provides several advantages over traditional western blotting.


Assuntos
Gravitação , Medicina de Precisão , Immunoblotting , Western Blotting , Colódio
5.
J Microbiol Biotechnol ; 34(2): 340-348, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-37986605

RESUMO

Salmonella, a major contributor to foodborne infections, typically causes self-limiting gastroenteritis. However, it is frequently invasive and disseminates across the intestinal epithelium, leading to deadly bacteremia. Although the genus is subdivided into >2,600 serotypes based on their antigenic determinants, only few serotypes are responsible for most human infections. In this study, a rapid dot-blot immunoassay was developed to diagnose multiple Salmonella enterica serotypes with high incidence rates in humans. The feasibility of 10 commercial antibodies (four polyclonal and six monoclonal antibodies) was tested using the 18 serotypes associated with 67.5% Salmonella infection cases in the United States of America (U.S.A) in 2016. Ab 3 (polyclonal; eight of 18 serotypes), Ab 8 (monoclonal; 13 of 18 serotypes), and Ab 9 (monoclonal; 10 of 18 serotypes) antibodies exhibited high detection rates in western blotting and combinations of two antibodies (Ab 3+8, Ab 3+9, and Ab 8+9) were applied to dot-blot assays. The combination of Ab 3+8 identified 15 of the tested 18 serotypes in 3 h, i.e., S. Enteritidis, S. Typhimurium, S. Javiana, S. I 4,[5],12:i:-, S. Infantis, S. Montevideo, S. Braenderup, S. Thompson, S. Saintpaul, S. Heidelberg, S. Oranienburg, S. Bareilly, S. Berta, S. Agona, and S. Anatum, which were responsible for 53.7% Salmonella infections in the U.S. in 2016. This cost-effective and rapid method can be utilized as an on-site colorimetric method for Salmonella detection.


Assuntos
Infecções por Salmonella , Salmonella enterica , Humanos , Sorogrupo , Salmonella , Infecções por Salmonella/diagnóstico , Immunoblotting , Sorotipagem
6.
STAR Protoc ; 5(1): 102783, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38103192

RESUMO

Tumor-derived small extracellular vesicles (TEVs) play a pivotal role in cancer progression by transferring functional biomolecules between the parental and recipient cells. Here, we present a protocol to isolate TEVs directly from murine primary mammary tumor using differential centrifugation. We describe steps for tissue dissociation, enzymatic digestion, and centrifugation. We then detail procedures for characterization of TEVs through transmission electron microscopy, immunoblotting, and nano-flow cytometry. This protocol can be used to extract EVs from other solid tumor types. For complete details on the use and execution of this protocol, please refer to Li, Mei-Xin et al. (2023).1.


Assuntos
Vesículas Extracelulares , Neoplasias Mamárias Animais , Animais , Camundongos , Centrifugação , Citometria de Fluxo , Immunoblotting
7.
STAR Protoc ; 5(1): 102802, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38159272

RESUMO

Locomotion through spatially confining spaces is an important in vivo migration mode. Here, we present a protocol for in situ visualization of mitochondrial reactive oxygen species and apoptosis in cancer cells during confined migration. We then detail sample preparation of confined cells for transcriptome and immunoblotting analysis by using transwell chambers. This approach allows in situ evaluation of a variety of cellular functions during confined migration and preparation of the samples of confined cells for further biochemical analysis. For complete details on the use and execution of this protocol, please refer to Cai et al.1.


Assuntos
Apoptose , Mitocôndrias , Espécies Reativas de Oxigênio , Immunoblotting , Locomoção
8.
Methods Enzymol ; 687: 87-102, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37666640

RESUMO

Manganese is one of the essential trace elements found in erythrocytes. Metal transporters situated on the plasma membrane generally facilitate the movement of manganese into and out of cells. This study aims at determining whether two recently discovered manganese importers, ZIP8 and ZIP14, are located in the erythrocyte membrane. We outline a simple, effective and repeatable method for the isolation of erythrocyte membrane from a minimum of 50 µL mouse blood, followed by the identification of ZIP metal transporters using immunoblotting. Our results revealed that ZIP8 is expressed within the erythrocyte membrane, in contrast to ZIP14 which is not identified using immunoblotting approach. A direct measurement of the ZIP8 protein expression in erythrocyte membranes could provide valuable information for further analyzing its biological function.


Assuntos
Membrana Eritrocítica , Manganês , Animais , Camundongos , Eritrócitos , Metais , Immunoblotting , Proteínas de Membrana Transportadoras
9.
J Biol Chem ; 299(10): 105233, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37690689

RESUMO

In many cell types, the E3 ubiquitin ligases c-Cbl and Cbl-b induce ligand-dependent ubiquitylation of the hepatocyte growth factor (HGF)-stimulated c-Met receptor and target it for lysosomal degradation. This study determines whether c-Cbl/Cbl-b are negative regulators of c-Met in the corneal epithelium (CE) and if their inhibition can augment c-Met-mediated CE homeostasis. Immortalized human corneal epithelial cells were transfected with Cas9 only (Cas9, control cells) or with Cas9 and c-Cbl/Cbl-b guide RNAs to knockout each gene singularly (-c-Cbl or -Cbl-b cells) or both genes (double KO [DKO] cells) and monitored for their responses to HGF. Cells were assessed for ligand-dependent c-Met ubiquitylation via immunoprecipitation, magnitude, and duration of c-Met receptor signaling via immunoblot and receptor trafficking by immunofluorescence. Single KO cells displayed a decrease in receptor ubiquitylation and an increase in phosphorylation compared to control. DKO cells had no detectable ubiquitylation, had delayed receptor trafficking, and a 2.3-fold increase in c-Met phosphorylation. Based on the observed changes in receptor trafficking and signaling, we examined HGF-dependent in vitro wound healing via live-cell time-lapse microscopy in control and DKO cells. HGF-treated DKO cells healed at approximately twice the rate of untreated cells. From these data, we have generated a model in which c-Cbl/Cbl-b mediate the ubiquitylation of c-Met, which targets the receptor through the endocytic pathway toward lysosomal degradation. In the absence of ubiquitylation, the stimulated receptor stays phosphorylated longer and enhances in vitro wound healing. We propose that c-Cbl and Cbl-b are promising pharmacologic targets for enhancing c-Met-mediated CE re-epithelialization.


Assuntos
Proteínas Proto-Oncogênicas c-cbl , Transdução de Sinais , Humanos , Ligantes , Proteínas Proto-Oncogênicas c-cbl/genética , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Fosforilação , Ubiquitinação , Immunoblotting
10.
Int Immunopharmacol ; 124(Pt B): 110953, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37757632

RESUMO

BACKGROUND: Pollens, particularly tree and plant pollens, are one of the major causes of allergic respiratory diseases worldwide. Allergy to pollens of different species of Salix trees has been reported in various regions of the world. The most common type of Salix tree in Iran is white willow (Salix alba). OBJECTIVES: This study aimed to identify and determine the immunochemical characteristics of allergenic proteins in S. alba tree pollen extract using SDS-PAGE and IgE- immunoblotting methods. Moreover, the cross-reaction pattern of the specific IgE antibody of S. alba tree pollen proteins with pollen allergens of common allergenic trees, i.e., Populus nigra (P. nigra), Cupressus sempervirens (C. sempervirens), Pinus brutia (P. brutia) and Platanus orientalis (P. orientalis) in the region was investigated. METHODS: The reaction of allergenic proteins in S. alba pollen extract with specific IgE antibodies in patients' sera was investigated using SDS-PAGE and IgE-immunoblotting methods. The cross-reaction of specific IgE antibodies of the proteins present in S. alba pollen extract with pollen allergens of common allergenic trees in the region was investigated using ELISA and immunoblotting inhibition methods. In silico methods such as phylogenetic tree drawing and alignment of amino acid sequences were used to examine the evolutionary relationship and homology structure of common allergenic proteins (Panallergens) responsible for cross reactions. RESULTS: More than 11 protein bands binding to specific IgE antibodies in patients' sera with a molecular weight between 13 and 95 kDa were identified in the S. alba tree pollen extract. ELISA and immunoblotting inhibition results showed that P. nigra extract could inhibit the binding of IgE antibodies to S. alba pollen extract proteins to a greater extent than C. sempervirens, P. brutia, and P. orientalis tree extracts. In silico methods investigated the results of ELISA and immunoblotting inhibition methods. Moreover, a high structural homology and evolutionary relationship were observed between S. alba and P. nigra tree pollen panallergens. CONCLUSION: In this study, it was found that more than 80 % of the sensitive patients who were examined had specific IgE antibodies reacting with the approximately a 15 kDa-protein present in the S. alba pollen extract. Furthermore, the specific IgE-binding proteins found in the pollens of S. alba and P. nigra trees had relative structural homology, and it is likely that if recombinant forms are produced, they can be used for diagnostic and therapeutic purposes for both of the trees.


Assuntos
Alérgenos , Salix , Humanos , Salix/metabolismo , Reações Cruzadas , Filogenia , Imunoglobulina E , Pólen , Extratos Vegetais/química , Immunoblotting , Proteínas de Plantas
11.
Methods Mol Biol ; 2696: 239-256, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37578727

RESUMO

Interleukin (IL)-1ß is a key mediator of inflammation and activates via pattern recognition receptors (PRR) of the inflammasome family by proteolytic maturation. Proteolysis is driven by proteases such as caspase-1 (also known as IL-1 converting enzyme, ICE) and converts the intact pro-IL-1ß ~31 kDa pro-peptide into a mature, ~17 kDa form that can exit cells through nanomolecular pores or via microvesicles. Whereas pro-IL-1ß fails to trigger IL-1 receptor (IL-1R) activation, mature IL-1ß, upon release from the cell, triggers pleiotropic downstream effects, establishing an inflammatory state. Hence, being able to detect IL-1ß conversion is physiologically relevant for measuring inflammation, but it cannot be easily accomplished by conventional ELISA or flow cytometry as most commercially available antibodies do not discriminate mature and pro-form. Furthermore, unlike for other cytokines, the mere induction and translation of IL1B mRNA cannot serve as a proxy of inflammasome PRR activation. Rather the cleavage of IL-1ß needs to be verified. Hence, conventional immunoblotting has emerged as the gold standard for demonstrating inflammasome activation as the difference in molecular weight between pro- and mature form can easily be detected. However, conventional immunoblotting suffers from poor standardization, quantification, and reproducibility, may require sample concentration, and is also not suitable for medium to high throughput. Some of these shortcomings are prohibitive for analysis of human primary samples but can be overcome by fully automated capillary-based immunoassay as we outline here. We here provide a practical guide to quantify pro- vs mature IL-1ß directly from unconcentrated supernatants of human monocyte-derived macrophages. The assay may be useful for more standardized and medium-throughput analysis in these cells or other biospecimen.


Assuntos
Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Humanos , Reprodutibilidade dos Testes , Células Cultivadas , Macrófagos , Interleucina-1beta , Immunoblotting , Inflamação , Caspase 1
12.
Am J Physiol Heart Circ Physiol ; 325(4): H601-H616, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37539459

RESUMO

The modification of serine and threonine amino acids of proteins by O-linked N-acetylglucosamine (O-GlcNAc) regulates the activity, stability, function, and subcellular localization of proteins. Dysregulation of O-GlcNAc homeostasis is well established as a hallmark of various cardiac diseases, including cardiac hypertrophy, heart failure, complications associated with diabetes, and responses to acute injuries such as oxidative stress and ischemia-reperfusion. Given the limited availability of site-specific O-GlcNAc antibodies, studies of changes in O-GlcNAcylation in the heart frequently use pan-O-GlcNAc antibodies for semiquantitative evaluation of overall O-GlcNAc levels. However, there is a high degree of variability in many published cardiac O-GlcNAc blots. For example, many blots often have regions that lack O-GlcNAc positive staining of proteins either below 50 or above 100 kDa. In some O-GlcNAc blots, only a few protein bands are detected, while in others, intense bands around 75 kDa dominate the gel due to nonspecific IgM band staining, making it difficult to visualize less intense bands. Therefore, the goal of this study was to develop a modifiable protocol that optimizes O-GlcNAc positive banding of proteins in cardiac tissue extracts. We showed that O-GlcNAc blots using CTD110.6 antibody of proteins ranging from <30 to ∼450 kDa could be obtained while also limiting nonspecific staining. We also show that some myofilament proteins are recognized by the CTD110.6 antibody. Therefore, by protocol optimization using the widely available CTD110.6 antibody, we found that it is possible to obtain pan-O-GlcNAc blots of cardiac tissue, which minimizes common limitations associated with this technique.NEW & NOTEWORTHY The post-translational modification of proteins by O-linked N-acetylglucosamine (O-GlcNAc) is recognized as mediating cardiac pathophysiology. However, there is considerable variability in the quality of O-GlcNAc immunoblots used to evaluate changes in cardiac O-GlcNAc levels. Here we show that with relatively minor changes to a commonly used protocol it is possible to minimize the intensity of nonspecific bands while also reproducibly generating O-GlcNAc immunoblots covering a range of molecular weights from <30 to ∼450 kDa.


Assuntos
Acetilglucosamina , Proteínas , Acetilglucosamina/química , Acetilglucosamina/metabolismo , Proteínas/metabolismo , Coração , Anticorpos , Immunoblotting , Processamento de Proteína Pós-Traducional , N-Acetilglucosaminiltransferases/genética , N-Acetilglucosaminiltransferases/metabolismo
13.
PLoS Negl Trop Dis ; 17(8): e0011535, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37540724

RESUMO

Endemic in Brazil, visceral leishmaniasis (VL) is a zoonotic infection that is among the most important parasitic diseases transmitted by vectors. Dogs are the main reservoirs of canine leishmaniasis (CanL) and their identification is used in some countries as part of disease prevention and control measures in the canine and human population. In this context, serological tests are necessary, composed of antigens capable of correctly identifying infected dogs, minimizing the number of false-negative cases. This study aimed to identify more immunoreactive peptides derived from two previously described whole proteins (rDyn-1 and rKDDR-plus) and compare their performance to the control antigens rK39 and the crude extract for the detection of dogs infected with L. infantum, especially the asymptomatic ones. The three selected peptides and a mixture of them, along with the rDyn-1, rKDDR-plus, rK39, and crude extract antigens were evaluated using indirect ELISA with sera samples from 186 dogs with CanL, being asymptomatic (n = 50), symptomatic (n = 50), co-infected (n = 19), infected with Babesia sp. (n = 7), Ehrlichia sp. (n = 6), T. cruzi (n = 20) and uninfected (n = 34). The results showed that the rDyn-1 protein and the peptide mixture had the highest sensitivity (100% and 98.32%, respectively) and specificity (97.01 and 98.51, respectively). A high degree of kappa agreement was found for rDyn-1 protein (0.977), mixed peptides (0.965), rKDDR-plus protein (0.953), K-plus peptide 1 (0.930) and Dyn-1 peptide (0.893). The mixture of peptides showed the highest likelihood (65.87). The ELISA using the mixture of peptides and the rDyn-1 protein showed high performance for CanL serodiagnosis. More mix combinations of the peptides and additional extended field tests with a larger sample size are recommended.


Assuntos
Doença de Chagas , Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Humanos , Cães , Animais , Antígenos de Protozoários , Sensibilidade e Especificidade , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/veterinária , Leishmaniose Visceral/epidemiologia , Peptídeos , Immunoblotting , Oligopeptídeos , Ensaio de Imunoadsorção Enzimática/métodos , Testes Sorológicos/métodos , Doenças do Cão/epidemiologia , Anticorpos Antiprotozoários
14.
Anal Chem ; 95(33): 12521-12531, 2023 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-37556853

RESUMO

There remains an unmet need for a fully integrated microfluidic platform that can automatically perform multistep and multireagent immunoassays. Here, we proposed a novel online dual-active valve-based centrifugal microfluidic chip, termed DAVM, for fully automatic point-of-care immunoassay. Practically, the puncture valve, one of the dual active valves, is capable of achieving precise, on-demand, sequential release of prestored reagents, while the other valve-reversible active valve enables controlled retention and drainage of the reaction solutions. Thereby, our technology mitigates the challenges of hydrophilic/hydrophobic modifications and unstable valve control performance commonly observed in passive valve controls. As a proof of concept, the indirect enzymatic immunoblotting technique was employed on DAVM for fully automated immunological analysis of eight targets, yielding outcomes within an hour. Furthermore, we conducted a comparative analysis of 28 clinical samples with autoimmune diseases. According to 224 clinical data, the sample testing concordance rate between DAVM and the traditional instrument was 82%, with a target compliance rate of 97%. Therefore, our DAVM system has powerful potential for fully automated immunoassays.


Assuntos
Técnicas Analíticas Microfluídicas , Microfluídica , Sistemas Automatizados de Assistência Junto ao Leito , Dispositivos Lab-On-A-Chip , Imunoensaio/métodos , Immunoblotting
15.
Br J Pharmacol ; 180(23): 3071-3091, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37461816

RESUMO

BACKGROUND AND PURPOSE: The scaffold molecule Axin2 is constitutively activated in colorectal cancer (CRC) and functions as a potent promoter of CRC behaviour. Pharmacological targeting of Axin2 may therefore exert a therapeutic effect in patients with CRC. Here, we discovered a potent small-molecule inhibitor of Axin2, based on the mechanism by which Axin2 is regulated post-translationally, and investigated its antitumour effects. EXPERIMENTAL APPROACH: Compound discovery and its inhibitory action on Axin2 protein were revealed by microscale thermophoresis, in vitro kinase assay, quantitative kinetic assay, immunoblotting/immunoprecipitation, RT-qPCR and cycloheximide pulse-chase assay. Compound antitumour effects and the underlying mechanisms were evaluated in multiple cell-based assays and mouse models. KEY RESULTS: We discovered that glycogen synthase kinase 3ß (GSK3ß) phosphorylates Axin2 at two consensus motifs and coupled Axin2 phosphorylation to its ubiquitination (mediated by the E3 ligase ß-Trcp2) and proteasomal degradation. The binding of Axin2 to GSK3ß in CRC cells is faint, which enables most of the Axin2 protein to maintain an unphosphorylated status and thereby permits the cells to preserve high levels of Axin2. Importantly, we identified a small-molecule compound CW85319 that enhances Axin2's interaction with GSK3ß via forming a high affinity for Axin2. Treatment of CRC cells with CW85319 enhanced Axin2 binding with GSK3ß, thereby promoting Axin2 phosphorylation, subsequent ubiquitination, and degradation. Furthermore, we demonstrated that CW85319 efficiently suppressed Axin2-driven CRC growth and metastasis, without eliciting side toxicity. CONCLUSIONS AND IMPLICATIONS: These findings suggest that pharmacological targeting of Axin2 by CW85319 may provide therapeutic benefits against certain human cancers, especially CRC.


Assuntos
Neoplasias Colorretais , Camundongos , Animais , Humanos , Linhagem Celular Tumoral , Glicogênio Sintase Quinase 3 beta , Modelos Animais de Doenças , Immunoblotting , Neoplasias Colorretais/metabolismo , Proteína Axina/metabolismo
16.
Methods Mol Biol ; 2689: 143-153, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37430052

RESUMO

Fast and accurate profiling of exogenous gene expression in host cells is crucial for studying gene function in cellular and molecular biology. This is achieved by co-expression of target genes and reporter genes, but we still have to face the challenge of incomplete co-expression of the reporter and target genes. Here, we present a single-cell transfection analysis chip (scTAC), which is based on the in situ microchip immunoblotting method, for rapid and accurate analysis of exogenous gene expression in thousands of individual host cells. scTAC not only can assign information of exogenous gene activity to specific transfected cells but can also enable the acquisition of continuous protein expression even in incomplete and low co-expression scenarios.


Assuntos
Biologia Molecular , Análise de Célula Única , Transfecção , Genes Reporter , Immunoblotting
17.
Parasite ; 30: 19, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37265252

RESUMO

Primary infection during pregnancy by the protozoan Toxoplasma gondii can be worrisome because transmission to the fetus may lead to congenital toxoplasmosis (CT). Neonatal diagnosis is usually performed by serological profile comparison of the mother and newborn. As previously reported in 2012 by C. L'Ollivier et al., three IgM bands at 75, 90 and 100 kDa called the "IgM triplet" has caught our attention and seems to be pathognomonic of CT. This retrospective multicenter study involved nine reference laboratories included in the French National Reference Center for Toxoplasmosis network and concerned determining the specificity and sensitivity of this IgM triplet. On this basis, we were able to propose a new read of the comparison of IgG and IgM immunoblot profiles of mother and infant to increase the sensitivity of this diagnostic marker. The effect of the trimester of pregnancy at the time of infection, but also of maternal treatment with pyrimethamine/sulfadiazine/folinic acid on the presence of this IgM triplet in the infant, could be studied. The presence of the triplet appears pathognomonic for the diagnosis of CT, and it increased the sensitivity of the immunoblot assay from 55.04% to 72.48%. As a result, it would be wise to enhance conventional immunoblot reading by adding the presence of the three IgM bands in the infant pattern for neonatal diagnosis of CT.


Title: La triplette IgM dans le diagnostic néonatal par immunoblot et son utilisation potentielle comme marqueur diagnostique de la toxoplasmose congénitale. Abstract: La primo-infection pendant la grossesse par le protozoaire Toxoplasma gondii peut se révéler préoccupante car la transmission au fœtus peut conduire à une toxoplasmose congénitale (TC). Un diagnostic néonatal est généralement réalisé par comparaison des profils sérologiques de la mère et du nouveau-né. Comme précédemment rapporté en 2012 par C. L'Ollivier et al., l'association de trois bandes d'IgM à 75, 90, et 100 kDa appelée la « triplette IgM ¼ a retenu notre attention et semble être pathognomonique de la TC. Cette étude rétrospective multicentrique impliquant neuf laboratoires de référence inclus dans le réseau du Centre National de Référence pour la Toxoplasmose a permis de déterminer la spécificité et la sensibilité de cette triplette IgM. Ainsi, cela a permis de proposer une nouvelle lecture de la comparaison des profils d'immunoblot IgG et IgM de la mère et du nourrisson pour augmenter la sensibilité de ce marqueur diagnostique. L'effet du trimestre de la grossesse au moment de l'infection mais aussi du traitement maternel par pyriméthamine/sulfadiazine/acide folinique sur la présence de la triplette IgM chez l'enfant a pu être analysé. La présence de cette triplette semble pathognomonique pour le diagnostic de TC et elle permet d'augmenter la sensibilité du test immunoblot de 55,04 % à 72,48 %. Ainsi, il pourrait être judicieux d'améliorer la lecture conventionnelle de l'immunoblot en ajoutant la présence des trois bandes IgM dans le schéma du nourrisson pour le diagnostic néonatal de TC.


Assuntos
Toxoplasma , Toxoplasmose Congênita , Toxoplasmose , Gravidez , Recém-Nascido , Lactente , Feminino , Humanos , Toxoplasmose Congênita/diagnóstico , Anticorpos Antiprotozoários , Immunoblotting , Toxoplasmose/diagnóstico , Imunoglobulina M
18.
Int J Mol Sci ; 24(11)2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37298148

RESUMO

The impact of innovative technologies on the target discovery has been employed here to characterize the interactome of STIRUR 41, a promising 3-fluoro-phenyl-5-pyrazolyl-urea derivative endowed with anti-cancer activity, on neuroblastoma-related cells. A drug affinity responsive target stability-based proteomic platform has been optimized to elucidate the molecular mechanism at the basis of STIRUR 41 action, together with immunoblotting analysis and in silico molecular docking. Ubiquitin Specific Protease 7 (USP-7), one of the deubiquitinating enzymes which protect substrate proteins from proteasomal degradation, has been identified as the most affine STIRUR 41 target. As further demonstrated by in vitro and in-cell assays, STIRUR 41 was able to inhibit both the enzymatic activity of USP-7 and its expression levels in neuroblastoma-related cells, thus laying an encouraging base for the blockade of USP-7 downstream signaling.


Assuntos
Neuroblastoma , Ureia , Humanos , Simulação de Acoplamento Molecular , Proteômica , Immunoblotting
19.
J Immunol Methods ; 518: 113493, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37196930

RESUMO

BACKGROUND: Aberrant ETV1 overexpression arising from gene rearrangements or mutations occur frequently in prostate cancer, round cell sarcomas, gastrointestinal stromal tumors, gliomas, and other malignancies. The absence of specific monoclonal antibodies (mAb) has limited its detection and our understanding of its oncogenic function. METHODS: An ETV1 specific rabbit mAb (29E4) was raised using an immunogenic peptide. Key residues essential for its binding were probed by ELISA and its binding kinetics were measured by surface plasmon resonance imaging (SPRi). Its selective binding to ETV1 was assessed by immunoblots and immunofluorescence assays (IFA), and by both single and double-immuno-histochemistry (IHC) assays on prostate cancer tissue specimens. RESULTS: Immunoblot results showed that the mAb is highly specific and lacked cross-reactivity with other ETS factors. A minimal epitope with two phenylalanine residues at its core was found to be required for effective mAb binding. SPRi measurements revealed an equilibrium dissociation constant in the picomolar range, confirming its high affinity. ETV1 (+) tumors were detected in prostate cancer tissue microarray cases evaluated. IHC staining of whole-mounted sections revealed glands with a mosaic staining pattern of cells that are partly ETV1 (+) and interspersed with ETV1 (-) cells. Duplex IHC, using ETV1 and ERG mAbs, detected collision tumors containing glands with distinct ETV1 (+) and ERG (+) cells. CONCLUSIONS: The selective detection of ETV1 by the 29E4 mAb in immunoblots, IFA, and IHC assays using human prostate tissue specimens reveals a potential utility for the diagnosis, the prognosis of prostate adenocarcinoma and other cancers, and the stratification of patients for treatment by ETV1 inhibitors.


Assuntos
Neoplasias da Próstata , Fatores de Transcrição , Masculino , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas de Ligação a DNA/genética , Anticorpos Monoclonais , Neoplasias da Próstata/diagnóstico , Immunoblotting
20.
J Clin Microbiol ; 61(6): e0011223, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-37222630

RESUMO

Treponema pallidum subsp. pallidum is a fastidious spirochete and the etiologic agent of syphilis, a sexually transmitted infection (STI). Syphilis diagnoses and disease staging are based on clinical findings and serologic testing. Moreover, according to most international guidelines, PCR analysis of swab samples from genital ulcers is included in the screening algorithm where possible. It has been suggested that PCR might be omitted from the screening algorithm due to low added value. As an alternative to PCR, IgM serology might be used. In this study, we wanted to establish the added value of PCR and IgM serology for diagnosing primary syphilis. Added value was defined as finding more cases of syphilis, preventing overtreatment, or limiting the extent of partner notification to more recent partners. We found that both PCR and IgM immunoblotting could aid the timely diagnosis of early syphilis in ~24% to 27% of patients. PCR has the greatest sensitivity and can be applied to cases with an ulcer with suspected reinfection or primary infection. In the absence of lesions, the IgM immunoblot could be used. However, the IgM immunoblot has better performance in cases with suspected primary infection than in reinfections. The target population, testing algorithm, time pressures, and costs should determine whether either test provides sufficient value to be implemented in clinical practice.


Assuntos
Testes Diagnósticos de Rotina , Imunoglobulina M , Sífilis , Humanos , Immunoblotting/normas , Imunoglobulina M/análise , Reação em Cadeia da Polimerase/normas , Sífilis/diagnóstico , Sífilis/imunologia , Sífilis/microbiologia , Treponema pallidum/genética , Testes Sorológicos/normas , Testes Diagnósticos de Rotina/economia , Testes Diagnósticos de Rotina/métodos , Testes Diagnósticos de Rotina/normas , Sensibilidade e Especificidade
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