Analysis of the serological variability of Lettuce mosaic virus using monoclonal antibodies and surface plasmon resonance technology

A panel of 19 monoclonal antibodies (mAbs) was used to study the immunological variability of Lettuce mosaic virus (LMV), a member of the genus Potyvirus, and to perform a first epitope characterization of this virus. Based on their specificity of recognition against a panel of 15 LMV isolates, the mAbs could be clustered in seven reactivity groups. Surface plasmon resonance analysis indicated the presence, on the LMV particles, of at least five independent recognition/ binding regions, correlating with the seven mAbs reactivity groups. The results demonstrate that LMV shows significant serological variability and shed light on the LMV epitope structure. The various mAbs should prove a new and efficient tool for LIVIV diagnostic and field epidemiology studies.

Sequence, evolution and ligand binding properties of mammalian Duffy antigen/receptor for chemokines

The Duffy antigen/receptor for chemokine, DARC, acts as a widely expressed promiscuous chemokine receptor and as the erythrocyte receptor for Plasmodium vivax. To gain insight into the evolution and structure/function relations of DARC, we analyzed the binding of anti-human Fy monoclonal antibodies (mAbs) and human chemokines to red blood cells (RBCs) from 11 nonhuman primates and two nonprimate mammals, and we elucidated the structures of the DARC genes from gorilla, gibbon, baboon, marmoset, tamarin, night monkey and cattle. CXCL-8 and CCL-5 chemokine binding analysis indicated that the promiscuous binding profile characteristic of DARC is conserved across species. Among three mAbs that detected the Fy6 epitope by flow cytometric analysis of human and chimpanzee RBCs, only one reacted with night monkey and squirrel monkey. Only chimpanzee RBCs bound a significant amount of the anti-Fy3 mAb. Fy3 was also poorly detected on RBCs from gorilla, baboon and rhesus monkey, but not from new world monkeys. Alignment of DARC homologous sequences allowed us to construct a phylogenetic tree in which all branchings were in accordance with current knowledge of primate phylogeny. Although DARC was expected to be under strong internal and external selection pressure, in order to maintain chemokine binding and avoid Plasmodium vivax binding, respectively, our present study did not provide arguments in favor of a selection pressure on the extracellular domains involved in ligand specificity. The amino acid variability of DARC-like polypeptides was found to be well correlated with the hydrophylicity indexes, with the highest divergence on the amino-terminal extracellular domain. Analysis of the deduced amino acid sequences highlighted the conservation of some amino acid residues, which should prove to be critical for the structural and functional properties of DARC.

Monoclonal antibodies against the 43,000 da glycoprotein from Paracoccidioides brasiliensis modulate laminin-mediated fungal adhesion to epithelial cells and pathogenesis

The surface glycoprotein gp43, a highly immunogenic component of Paracoccidioides brasiliensis, is used in the serodiagnosis of paracoccidioidomycosis (PCM) and has recently been shown to specifically bind the extracellular matrix protein laminin, Binding to laminin induces the increased adhesion of the fungus to epithelial cells; a hamster testicle infection model has shown that the gp43-dependent binding of fungal cells to laminin enhances their pathogenicity in vivo. We report on the production and characterization of 12 monoclonal antibodies against the gp43 that recognize peptide sequences in the molecule detecting at least three different epitopes as well as different isoforms of this antigen. MAbs interfered in the fungal pathogenicity in vivo either by inhibiting or enhancing granuloma formation and tissue destruction, Results suggest that P. brasiliensis propagules may start infection in man by strongly adhering to human lung cells, Thus, laminin-mediated fungal adhesion to human lung carcinoma (A549) cells was much more intense than to Madin-Darby canine kidney cells (MDCK), indicating differences in binding affinity, Subsequent growth of fungi bound to the lung cells could induce the granulomatous inflammatory reaction characteristic of PCM. Both steps are greatly stimulated by laminin binding in infective cells expressing gp43.

Laminin-binding epitope on gp43 from Paracoccidioides brasiliensis is recognized by a monoclonal antibody raised against Staphylococcus aureus laminin receptor

Adhesion is regarded as an important step in the pathogenesis of several microorganisms. Thus, the ability to recognize extracellular matrix proteins, such as laminin or fibronectin, has been correlated with invasiveness. Studying the already characterized laminin-binding protein of Paracoccidioides brasiliensis, the 43 kDa glycoprotein (gp43), we evaluated whether MAb 1.H12, raised against the laminin-binding protein from Staphylococcus aureus, cross-reacts with that fungal protein. By immunoblot analysis we show that MAb 1.H12 recognizes gp43. This interaction is able to inhibit the laminin-mediated adhesion to epithelial cells as well as the P. brasiliensis infection in vivo. Moreover, through immunoenzymatic assays, we show that MAb 1.H12 recognizes gp43 in solid phase and that this interaction is partially inhibited by the addition of anti-gp43 MAbs. These results show that MAb 1.H12 recognizes the gp43, suggesting the presence of an epitope similar to those found in the other laminin-binding proteins from phylogenetically very distant cells. These findings reinforce the possibility of evolutionary conservation of such epitopes.

Análise do desempenho da técnica de clonagem celular por micromanipulação versus diluição limitante

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização e validação de anticorpo monoclonal murino anti-Linfócitos B humanos para uso em citometria de fluxo e imunoquímica

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Foto seleção de mielomas e hibridomas murinos na produção de anticorpos monoclonais

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Produção de anticorpos monoclonais murinos dirigidos contra células-tronco mesenquimais de coelho

Mesenchymal stem cells (MSCs) are a heterogeneous population of cells that proliferate in vitro as plastic-adherent cells, have fibroblast-like morphology and can differentiate into bone, cartilage and fat cells. Therapeutic potential of MSCs have been studied in experimental models, such as rabbit, in Laboratory of Cell Engineering of Botucatu. However, no specific markers have been reported for expanded rabbit MSCs, which hampers the isolation of pure MSC populations by immunophenotypic characterization. Thus, the objective of this study was to produce monoclonal antibodies (mAbs) to rabbit MSCs. MSCs derived from rabbit bone marrow (BM) were isolated, cultured, expanded ex vivo, and immunized into three BALB/c mices, and spleen cells subsequently harvested were used to generate hibridoma cell lines secreting antibodies against MSCs. Hybridoma cells were screened by flow cytometry and antibody-producing cells were subjected to subsequent rounds of retests. MSC1-160 obtained the best positivity for IgG expression and was cloned by limiting dilutions and micromanipulation. Ascitic fluid from ten best clones was purified by affinity chromatography in Protein A-sepharose CL-4B column and purification control was performed by electrophoresis in agarose gels. The purified IgG were tested against rabbit MSCs, obtaining high positivity by flow Cytometry. In conclusion, we developed 10 mAbs, MSC1-160 A20, A30, A41, A47, A55, A60, A63, A69, A81, and A82, that recognize rabbit MSC cell surface antigens showing potential for immunophenotypic characterization of rabbit MSC cell lines

Influência da luz LED na cultura celular de Mieloma múltiplo murino–NS1 in vitro

A monoclonal antibody (mAb) is an important tool in medical biotechnology and the production of biopharmaceuticals, especially for disease diagnosis and treatment of infections, because the antibodies have a significant advantage over chemical agents used in conventional therapies . The last thirty years the technology of production of monoclonal antibodies developed mainly the technique of obtaining in vitro, but also of their production is laborious, the cost is high. A major element of the high cost of production is the fact that the long-term culture consumes a large amount of imported inputs with high added value. A major contribution of this work is to promote cell growth more quickly and efficiently. Currently, a great race to discover new technologies and techniques to synthesize new antibodies and significantly increase the production of murine mAbs. New technologies such as laser and LED are innovations and widespread in modern life, so much so that its use has proliferated worldwide, primarily in the medical field. Recent studies show a series of results from the influence of the LED light in biological tissues such as: increasing the rate of cell proliferation, increased production rate of fibroblasts, increasing the rate of synthesis of RNA and DNA synthesis of ATP, etc. To assess the contribution of the LED in the culture of Myeloma NS1murino compared to the standard procedure. - NS1 cells were provided and followed the criteria of culture medium of the Laboratory of Cellular Engineering Center of Botucatu (POPs). The same amount of cells was grown in bottles of 25 cm2 polystyrene Tissue Culture Treated, specifically marked and kept in special medium RPMI 1640 Gibco BRL  supplemented with fetal bovine serum 10%, essential amino acids and non-essential, glucose, insulin and antibiotics. It was used in LEDs Cromatek wavelength of 630nm, 475nm and 530nm. The groups were... (Complete abstract click electronic access below)

Caracterização de anticorpos anti-idiotípicos e anti-anti-idiotípicos de BEVACIZUMAB

Propomos avaliar o potencial de uma abordagem imunoterápica que tem o fator de crescimento do endotélio vascular (VEGF) como alvo. A angiogênese é necessária para nutrir o tumor e propicia sua metastatização. Sabe-se que VEGF é produzido pela maioria dos tumores sólidos metastatizantes. A eficiência do anticorpo anti-VEGF, BEVACIZUMAB, já foi demonstrada. Entretanto, efeitos adversos limitam sua utilização em alguns casos e, com base na teoria da rede idiotípica e na experiência do grupo com anticorpos anti-idiotípicos (anti-Id ou AB2), anticorpos AB2 capazes de mimetizar VEGF foram obtidos. Assim, com o objetivo de explorar o rationale, dois anticorpos monoclonais (MAb) anti-Id de Bevacizumab, 10.D7 e 3.E3, foram produzidos em nosso laboratório. O controle da purificação de anticorpos foi feito através da avaliação do material purificado em géis de poliacrilamida. Immunoblots comprovaram a especificidade do reconhecimento do idiotipo de Bevacizumab pelos MAbs anti-Id. Foi mostrado que os AB2 obtidos se ligam a moléculas da superfície de células endoteliais, que expressam receptores de VEGF, sugerindo que esses anticorpos mimetizam VEGF. Entretanto, não foi possível verificar inibição do crescimento dessas células quando cultivadas em presença desses MAbs. Será necessária a otimização dos protocolos utilizados para uma avaliação mais definitiva. Uma vez demonstrada a atividade anti-idiotípica dos AB2 in vitro, 10.D7 e 3.E3 foram utilizados como imunógenos em camundongos Balb/c, com o objetivo de avaliar a resposta AB3 ou anti-anti-Id. Por meio de ensaio imunoenzimático (ELISA) indireto foi verificada a presença de anticorpos anti-anti-Id ligantes de VEGF nos soros dos camundongos imunizados. Os animais imunizados com o MAb 10.D7 responderam melhor do que os imunizados com 3.E3. Anticorpos IgG purificados dos soros desses animais reconheceram VEGF em ensaios imunoenzimáticos. Foram então selecionados os ...

Desenvolvimento de imunossensor baseado na imobilização de anticorpo monoclonal em fibroína da seda para diagnóstico rápido da cisticercose bovina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Products for the treatment of inflammatory bowel disease: a patent review (2013-2014)

Introduction: Inflammatory bowel disease (IBD) consists of Crohn's disease, ulcerative colitis and an unspecific IBD. The unclear etiology of IBD is a limiting factor that complicates the development of new pharmacological treatments and explains the high frequency of refractory patients to current drugs, including both conventional and biological therapies. In view of this, recent progress on the development of novel patented products to treat IBD was reviewed.Areas covered: Evaluation of the patent literature during the period 2013 - 2014 focused on chemical compounds, functional foods and biological therapy useful for the treatment of IBD.Expert opinion: Majority of the patents are not conclusive because they were based on data from unspecific methods not related to intestinal inflammation and, when related to IBD models, few biochemical and molecular evaluations that could be corroborating their use in human IBD were presented. On the other hand, methods and strategies using new formulations of conventional drugs, guanylyl cyclase C peptide agonists, compounds that influence anti-adhesion molecules, mAbs anti-type I interferons and anti-integrin, oligonucleotide antisense Smad7, growth factor neuregulin 4 and functional foods, particularly fermented wheat germ with Saccharomyces cerevisiae, are promising products for use in the very near future.