Evaluation of ELISA procedures to detect von Willebrand Factor with monoclonal antibodies

The von Willebrand Factor is a multimeric glycoprotein responsible for the promotion of platelet adhesion and aggregation at sites of vascular injury, and for FVIII stabilization. Abnormalities on this protein are responsible for diverse types of von Willebrand Disease. In the present study, monoclonal antibodies against human von Willebrand Factor were developed as a means to improve von Willebrand Disease research and diagnosis. Monoclonal antibodies were tested for their ability to bind to purified and plasmatic von Willebrand Factor. Monoclonal antibodies vW22 and vW23 were found to bind only purified von Willebrand Factor, and monoclonal antibodies vW18 and vW21 were found to bind purified and plasmatic von Willebrand Factor. Antibodies vW18 and vW21 were used to perform a sandwich-enzyme-linked immunosorbent assay to detect and quantify von Willebrand Factor concentration in plasma samples from 143 coagulopathy patients and 12 healthy blood donors. The assay showed high performance, with strong correlation and agreement in results, when compared to electroimmunoassay (Rs = 0.843 and K = 0.691 with p<0.001) and a commercial ELISA (Rs = 0.930 and K = 0.819 with p<0.001). S-ELISA proved to be a useful tool in vWF quantification tests in Brazilian specialized laboratories as an alternative to imported tests.(Avaliação de procedimentos ELISA para detectar o Fator von Willebrand com anticorpos monoclonais). O Fator von Willebrand é uma glicoproteína multimérica responsável pela promoção da adesão e agregação de plaquetas nos locais de lesão vascular e pela estabilização do FVIII. Anormalidades na função ou estrutura desta proteína são responsáveis por diversos tipos de doença de von Willebrand. Para auxiliar na pesquisa e diagnóstico da doença de von Willebrand, este estudo desenvolveu anticorpos monoclonais contra fator von Willebrand humano. Os anticorpos monoclonais foram testados quanto à sua capacidade de se ligar ao fator von Willebrand purificado e plasmático. Os anticorpos monoclonais vW22 e vW23 ligaram-se somente ao fator von Willebrand purificado, e anticorpos monoclonais vW18 e vW21 ligaram-se tanto ao fator von Willebrand purificado como ao plasmático. Anticorpos vW18 e vW21 foram utilizados no desenvolvimento de um ELISA sandwich para detectar e quantificar a concentração de fator von Willebrand no plasma em uma amostra de 143 pacientes com coagulopatias e 12 doadores de sangue saudáveis. O teste mostrou alto desempenho, com forte correlação e concordância quando comparado com uma imunoeletrofose (Rs = 0,843 e K = 0,691 p <0,001) e um ELISA comercial (Rs = 0,930 e K = 0,819 p <0,001). O ELISA-S desenvolvido no presente trabalho mostrou um bom desempenho para ser usado como teste de quantificação vWF em laboratórios especializados no Brasil como alternativa para testes importados

Purification and ultrastructural localization of a copper–zinc superoxide dismutase (CuZnSOD) from the entomopathogenic and acaricide fungus Metarhizium anisopliae

The entomopathogenic fungus Metarhizium anisopliae contains three superoxide dismutases. One of these enzymes was purified and partially characterized as a CuZnSOD. The enzyme has an estimated molecular mass of 30 690 Da and a specific activity of 3838.89 U mg−1. SDS-PAGE and 2D gels show a single band of protein in the fractions eluted from the gel filtration column with a molecular mass of 20 000 and ∼15 000 Da, respectively, and a pI of 6.0. These results suggest that the native enzyme is a dimer consisting of two subunits. Polyclonal antiserum were raised against purified CuZnSOD and used to determine its subcellular localization by immunoelectron microscopy. M. anisopliae CuZnSOD is present in the cell wall

Anti-tick monoclonal antibody applied by artificial capillary feeding in Rhipicephalus (Boophilus) microplus females

AbstractThe tick Rhipicephalus microplus is an ectoparasite harmful to livestock, a vector of disease agents that affects meat and milk production. However, resistance to acaricides reflects the need for alternative tick control methods, among which vaccines have gained increasing relevance. In this scenario, monoclonal antibodies can be used to identify and characterize antigens that can be used as vaccine immunogens. Capillary tube artificial feeding of partially engorged R. microplus females with monoclonal antibodies against proteins from the gut of tick were used to test the effects of immunoglobulins in the physiology of the parasite. The results of artificial feeding showed that female ticks over 25mg and under 60mg in weight performed better in the artificial feeding process, with a 94–168% weight increase after 24h of feeding. Results showed that artificial feeding of ticks proved to be a viable technique to study the effects of antibodies or drugs in the physiology of the parasite. One monoclonal antibody (BrBm2) induced decreased oviposition. Moreover, the antigen recognized by BrBm2 was identified as a 27-kDa protein and immunolabeled on digestive vesicles membranes of digestive cells of partially and fully engorged females

Inhibition of enzyne activity of Riphicephalus (Boophilus) microplus triosephosphate isomerase and BME26 cell growth by monoclonal antibodies

In the present work, we produced two monoclonal antibodies (BrBm37 and BrBm38) and tested their action against the triosephosphate isomerase of Rhipicephalus (Boophilus) microplus (RmTIM). These antibodies recognize epitopes on both the native and recombinant forms of the protein. rRmTIM inhibition by BrBm37 was up to 85% whereas that of BrBrm38 was 98%, depending on the antibody-enzyme ratio. RmTIM activity was lower in ovarian, gut, and fat body tissue extracts treated with BrBm37 or BrBm38 mAbs. The proliferation of the embryonic tick cell line (BME26) was inhibited by BrBm37 and BrBm38 mAbs. In summary, the results reveal that it is possible to interfere with the RmTIM function using antibodies, even in intact cells

Produção de anticorpos monoclonais contra o antígeno B/2 recombinante de Echinococcus granulosus

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Produção e purificação da proteína recombinante malato desidrogenase citosólica de Echinococcus granulosus

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Produção e purificação da proteína recombinante malato desidrogenase citosólica de Echinococcus granulosus

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Clonagem em vetor de expressão em eucarioto de uma Catepsina-L de Boophilus microplus

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Produção de anticorpos monoclonais contra o antígeno B/2 recombinante de Echinococcus granulosus

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