Examinando por Autor "Docena, Guillermo"
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Acceso Abierto Allergenicity reduction of cow’s milk proteins using latex peptidases(2019) Oliveira, João P.B.; Candreva, Ángela María; Rizzo, Gastón; Ramos, Márcio V.; Oliveira, Jefferson S.; Oliveira, Hermógenes D.; Ary, Maria B.; Docena, Guillermo; Freitas, Cleverson D.T.The present study evaluated four laticifer fluids as a novel source of peptidases capable of hydrolyzing proteins in cow’s milk. The latex peptidases from Calotropis procera (CpLP), Cryptostegia grandiflora (CgLP), and Carica papaya (CapLP) were able to perform total hydrolysis of caseins after 30 min at pH 6.5, as confirmed by a significant reduction in the residual antigenicity. Casein hydrolysis by Plumeria rubra latex peptidases (PrLP) was negligible. Moreover, whey proteins were more resistant to proteolysis by latex peptidases; however, heat pretreatment of the whey proteins enhanced the degree of hydrolysis and reduced the residual antigenicity of the hydrolysates. The in vivo assays show that the cow’s milk proteins hydrolysed by CgLP and CapLP exhibited no immune reactions in mice allergic to cow’s milk, similar to a commercial partially hydrolysed formula. Thus, these peptidases are promising enzymes for the development of novel hypoallergenic formulas for children with a milk allergy. - Documento de conferencia
Acceso Abierto Characterization of nanoparticles for vaccine development(2019) Rizzo, Gastón; Smaldini, Paola; Herrera, Santiago; Agazzi, Maximiliano; Cortez, Lorena; Azzaroni, Omar; Docena, GuillermoNanotechnology are becoming to play an important role in vaccine development, it offers the opportunity to design nanoparticles varying in composition, size, shape and surface properties for application in the fields of medicine. In this work, we aimed to characterize nanoparticles as a safety adjuvant for further use in immunotherapies. Polycationic polymer nanoparticles (R3N0) were used in BMDC to characterize them in vitro. Nanoparticle-cell interaction (internalization or adhesion) was evaluated by microscopy and cell phenotype activation (MHCII and CD86) were determined by flow-cytometry. IL-1β-production was also evaluated by ELISA. Furthermore, Balb/c mice were intraperitoneally sensitized with R3N0, R3N0 plus OVA (combined) and OVA conjugated to R3N0. Finally, humoral (serum antibodies) and cellular immune response (cytokines) was evaluated by ELISA and flow cytometry. We found that R3N0 is internalized by the cells generating its activation with an increase in the expression of CD86 and IL-1β. In turn, R3N0 promotes grater stimulation and release of IL-1β than the positive control (P<0.05). IL-1β was abrogated by the presence of inhibitors of the pathways that activate the inflammosome NLRP3. In vivo, we observed that the OVA-specific-IgG levels were much higher than those corresponding to the adjuvant used as a positive control (P<0.05). Immunized mice showed an increase of IFN-γ by LTCD4 and LTCD8. In conclusion, we found that R3N0 are internalized by BMDC and activates them with the production of proinflammatory cytokines. Moreover, this nanoparticle may have a potential adjuvant effect with the production of Th1 specific antibodies and an IFN-γ dependent cell response. - Artículo
Acceso Abierto Evaluación ponderal de tres alternativas terapéuticas en niños con diarrea crónica y desnutrición: dieta, hidrolizados y probióticos(2008) Guzmán, Luciana L.; Nanfito, Gabriela; Rey, Amanda; Drut, Ricardo; Docena, Guillermo; Cueto Rua, Eduardo ÁngelSe presenta la evolución clínica de tres grupos de pacientes desnutridos con diarrea crónica en los que se descartaron entidades específicas y que fueron sometidos tres alternativas terapéuticas: dieta hipofermentativa, hidrolizados de leche de vaca y probiótico de uso farmacológico, con un control ponderal durante tres meses. Si bien no hubo diferencias significativas en cuanto al progreso de peso, sí las hubo en cuanto a costos. Palabras clave: alergia a la leche de vaca, desnutrición, diarrea crónica, hidrolizado, probiótico. - Documento de conferencia
Acceso Abierto Immunomodulatory properties of heat-killed Rhodococcus coprophilus control the allergic reaction in a mouse model of food allergy(2018) Rizzo, Gastón; Quereda, Micaela; Smaldini, Paola; Docena, GuillermoActinomyces are soil bacteria with immunomodulatory properties that exert biological effects on intestinal epithelial cells in different inflammatory contexts. Our goal is to study the inhibitory effect of dead Rhodococcus coprophilus-Rc on activated epithelial cells exposed to pro-inflammatory stimuli, and in an experimental food allergy model. Colon cell lines (Caco-2 and Caco-luc) were cultured with flagellin (FliC) and the induction of cytokines (IL-1b, IL-6, TNFa) and chemokines (CCL20, IL-8 and MCP-1) were studied by qPCR, while Nf-κB was analyzed by immunoblotting. In addition, Balb/c mice were sensitized with cow´s milk proteins (CMP) plus cholera toxin by gavage, and orally challenged with CMP to induce intestinal inflammation and hypersensitivity symptoms. Activated cell lines were exposed to Rc before or during activation. On the other hand, mice received Rc by gavage during one week, and then they were sensitized.. The therapeutic effect of Rc was monitored in vivo (clinical score and cutaneous test) and in vitro (serum specific antibodies and cytokines by ELISA, and cell analysis by flow cytometry). We found that Caco cells were unresponsive to dead bacteria; however, in FliC-activated cells Rc suppressed the induction of pro-inflammatory cytokines (p<0.05) and chemokines (p<0.05), with a reduced traslocation of p65 onto the nucleus. This inhibitory effect was also observed in experimental food allergy with the intragastric administration of Rc.Symptoms and serum specific IgE levels were lower in Rc-treated mice compared with sensitized mice (p<0.05), with a concomitant reduction of IL-5 (p<0.05) and intestinal CCL20 (p<0.05). In conclusion, we found that Rhodoccocus coprophilus modulated the NF-KB pathway, abrogated the production of pro-inflammatory cytokines and chemokines in intestinal epithelial cells and ameliorated hypersensitivity and the Th2-mediated immune response in the food allergy mouse model. - Documento de conferencia
Acceso Abierto Peptides from Amaranth controlled the NF-κB pathway activation on epithelial cells and suppressed intestinal inflammation(2018) Smaldini, Paola; Quereda, Micaela; Rizzo, Gastón; Orsini Delgado, Maria Lucia; Moronta, Julian; Añón, María Cristina; Docena, GuillermoBiological, nutritional and health benefits of amaranth have been highlighted in the last years. Proteins of amaranth exert anti-hypertensive, anti-oxidant, anti-thrombotic and anti-proliferative effects. The aim of this study was to analyze the anti-inflammatory effect of peptides from amaranth on NF-kB-intracellular pathway activation in intestinal epithelial cells, and in experimental intestinal inflammation, such as colitis and food allergy. Colon cell lines (Caco-2 and Caco-luc) were cultured with flagellin and amaranth peptides. CCL20-expression was evaluated by qPCR and NF-κB modulation was evaluated by light emission and qPCR, along with p65-nuclear traslocation. In vivo studies included the oral administration of a formulation containing the peptide during the allergic sensitization or the colitis induction phase in Balb/c mice. Treatment efficacy was in vivo and in vitro evaluated. We found several peptides with anti-inflammatory capacity and we selected that with the highest ability to suppress cell activation (decrease in CCL20 and light emission p<0.05). In vivo studies showed, an amelioration of the clinical score (p<0.01) in the food allergy mouse model, with inhibition of specific-IgE secretion (p<0.05) and negativitization of the cutaneous test (mean increase in footpad thickness control: 0.6mm vs peptide-treated: 0.3mm; p<0.05); intestinal nf-kb gene expression was reduced (fold change=3; p<0.01) along with up-regulation of tfg-b and foxp3. In the colitis mouse model, we found a decrease of the histologic score with a decrease expression and production of pro-inflammatory cytokines (IL-1b, TNF and IFNg, p<0.05) and a decrease in the myeloperoxidase activity in the peptide-treated group compared to control (p<0.05). NF-κB pathway was also abrogated in the gut. In conclusion, our findings indicated that peptides from amaranth endowed mucosal anti-inflammatory properties that suppressed the intestinal activation of NF-kB in Th1- and Th2-mediated inflammation. These findings led us to propose that this peptide might be included in the composition of a functional food