Conjugação e validação de controle isotípico IgG1-FITC para uso em citometria de fluxo

Em meados da década de 50 iniciou-se o desenvolvimento da citometria de fluxo, tecnologia que permite verificar características físico-químicas de células ou partículas suspensas em meio fluido. Esta tecnologia utiliza anticorpos monoclonais marcados com fluorocromos como ferramenta de investigação em diversas análises e necessita de controles isotípicos para definição da região negativa (background). Estes controles são constituídos por imunoglobulinas de mesmo isotipo e fluorocromo dos anticorpos testes, sendo o isotiocianato de fluoresceína (FITC) o marcador fluorescente mais utilizado na conjugação de anticorpos. Os controles isotípicos têm como função definir a fluorescência inespecífica (células negativas) e as regiões fluorescentes (células positivas). No presente estudo foi selecionado anticorpo monoclonal murino (AcMm) dirigido contra antígeno eritrocitário canino, produzido no Laboratório de Anticorpos Monoclonais do Hemocentro de Botucatu, o qual reage positivamente com hemácias de cães, mas nunca com leucócitos humanos, tendo, portanto, potencial utilidade como controle negativo em citometria de fluxo. A purificação do AcMm da subclasse IgG1 foi feita por cromatografia de afinidade em Proteína-A Sepharose, e o controle da purificação realizado por eletroforese em géis de ágarose e poliacrilamida (SDS-PAGE). A imunoglobulina purificada foi conjugada ao FITC e filtrado em coluna de Sephadex G-25 para separação das proteínas marcadas e não-marcadas. O AcMm conjugado foi testado contra hemácias de cães, e o êxito da conjugação comprovado por testes de fluorescência, sendo a mediana de positividade de 94,70. Frente a leucócitos humanos a mediana de positividade foi 0,03 contra 0,50 dos reagentes comerciais. Os testes estatísticos não-paramétricos de Wilcoxon e correlação de Spearman comprovaram a eficiência e validam o controle isotípico produzido em comparação aos reagentes comerciais testados.It was during the 1950's that the development of flow cytometry started, technology that allow to measure physiochemical characteristics of cells or suspended particles in fluid. This technology uses monoclonal antibodies labeled by fluorochromes as investigation tool in several analysis and needs isotype controls to define the negative region (background). These controls are constituted by immunoglobulins of the same isotype and fluorochrome from test antibodies, being fluorescein isothiocyanate (FITC) the most fluorescent marker used in antibody conjugations. The isotype controls have the function to define the unspecific fluorescence (negative cells) and the fluorescent regions (positive cells). In this study was selected monoclonal antibody (mAb) against canine erythrocyte antigen, produced in the Monoclonal Antibodies Laboratory - Blood Center of Botucatu, which reacts positively with dog red blood cells, but never with human leukocytes, having therefore, utility potential as negative control in flow cytometry. The purification mAb of IgG1 subclass was made by affinity chromatography in Sepharose Protein-A and the purification control was performed by electrophoresis in ágarose and polyacrylamide gels (SDS-PAGE). The purified immunoglobulin was conjugated to FITC and after was filtered in Sephadex G25 column to separation of labeled and unlabeled proteins. The conjugated mAb was tested against dog red blood cells and the conjugation success was verified by fluorescence tests, being the median positivity of 94.70. To the human leucocytes the positivity median was 0.03 against 0.50 of the commercial reagents. The nonparametric statistical tests of Wilcoxon and the correlation Spearman showed the efficiency and validate the isotype control produced in relation to the tested commercial reagents

Avaliação das subclasses IgG1 e IgG3 na doença hemolítica perinatal

A doença hemolítica perinatal (DHPN) ainda é um problema clínico. Nenhum teste isolado prediz, com segurança, a gravidade do quadro hemolítico. O objetivo do presente estudo foi determinar as subclasses de anticorpos IgG1 e IgG3 por citometria de fluxo no soro de 42 gestantes isoimunizadas e correlacionar os dados obtidos com a gravidade da DHPN. A distribuição dos fetos ou neonatos segundo a gravidade do quadro hemolítico evidenciou 13 casos com doença leve, 16 casos com doença moderada e 13 com doença grave. As subclasses foram detectadas em 33/42 (79%) amostras. A subclasse IgG1, isoladamente, foi evidenciada em 14/33 (42,4%) casos. Na relação entre gravidade da doença e subclasses de IgG, observou-se que IgG1 isolada foi encontrada em todos os grupos, e os valores da mediana de intensidade de fluorescência (MIF) foram significativamente mais altos nas formas mais graves da DHPN (p<0,01). Contrariamente, os valores da MIF para IgG3 se apresentaram mais homogêneos em todas as categorias (p=0,11). A presença de IgG3 parece, portanto, estar mais associada à hemólise leve. A associação das subclasses IgG1 e IgG3 está relacionada à situação clínica mais grave, o que se deve, possivelmente, à presença de IgG1 associada. Apesar dos altos valores para IgG1 e a associação de IgG1 com IgG3 indicarem maior gravidade da DHPN, sugere-se que outras variáveis sejam analisadas conjuntamente, uma vez que os relatos existentes na literatura, até o momento, não dão suporte para seu uso como instrumento exclusivo de avaliação de gravidade e prognóstico da doença.The hemolytic disease of the newborn (HDN) continues to be a clinical problem in spite of prophylaxis. To date, none of the available tests, developed to predict the severity of HDN, has provided complete reliability. The objective of the present study was to determine the IgG1 and IgG3 subclasses in 42 isoimmunized pregnant women, and to correlate them with clinical severity of hemolytic disease. The IgG subclasses were determined employing flow cytometry. According to the clinical severity of HDN, fetuses and newborn babies were classified as 13 mild, 16 moderate and 13 severe cases. The IgG subclasses were detected in 33 of the 42 pregnant women. of these, IgG1 was predominant in 72.7% of the cases; either isolated (42.4%) or in association with IgG3 (30.3%). IgG1 was present in all the three clinical severity categories, however, its values were significantly higher in cases with greater clinical severity of HDN (p<0.01). on the other hand, the distribution of IgG3 values within each group was not statistically significant (p=0.11). IgG3 seems to be more associated with the mild hemolytic form of the disease, whereas the association of IgG1 and IgG3 suggested a clinically more severe form of HDN. It is possible, however, that the severity in these cases is related to the presence of IgG1. These results suggest that IgG1 and IgG3 isotypes should be included in multi-parametric protocols for the evaluation of clinical severity of HDN, as International literature does not give support to the use of IgG subclass determination alone as a reliable indicator to predict severity or prognosis of the disease

Taenia saginata: Production and characterization of monoclonal antibodies against Taenia saginata metacestode antigens

Cysticercosis is a major cause of economic loss in bovine production due to meat condemnation. Chemotherapy is being used in Brazilian cattle and a diagnostic test to improve the treatment program is desired. We produced monoclonal antibodies against crude (TAEB) and cyst fluid (TAEF) Taenia saginata metacestode antigens using immunized BALB/c mice. After cell fusion, 10 TAEB and nine TAEF hybrids were selected and cloned resulting in 18 IgG(1), and 32 IgM TAEB clones, and 9 IgG(1), and 9 IgM TAEF clones. Ascites was produced and Western blot testing was performed resulting in reactivity to protein fractions of low molecular weight (<18 kDa), 43, 55, 66 and 100 kDa. The indirect immunofluorescence test, with one monoclonal antibody against crude and one against cyst fluid antigens, recognized antigenic fractions of both the scolex and the bladder wall of metacestodes from naturally infected bovine. (C) 2010 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Agaricus brasiliensis polysaccharides stimulate human monocytes to capture Candida albicans, express toll-like receptors 2 and 4, and produce pro-inflammatory cytokines

<div><p>Abstract Background Agaricus brasiliensis is a medicinal mushroom with immunomodulatory and antitumor activities attributed to the β-glucans presented in the polysaccharide fraction of its fruiting body. Since β-glucans enhance cellular immunoresponsiveness, in this study we aimed to evaluate the effect of an acid-treated polysaccharide-rich fraction (ATF) of A. brasiliensis on the ability of human monocytes to adhere/phagocyte C. albicans yeast cells, their expression of pattern recognition receptors and their ability to produce cytokines. Methods Adhesion/phagocytosis of FITC-labeled C. albicans was evaluated by flow cytometry. Cells were incubated with specific fluorochrome-labeled antibodies for TLR2 and 4, βGR and MR and also evaluated by flow cytometry. Monocytes were cultured with ATF, and culture supernatants were collected for analysis of in vitro cytokine production by ELISA (TNF-α, IL-1β, IL-12 and IL-10). Results ATF significantly increased the adherence/phagocytosis of C. albicans by monocytes and this was associated with enhanced expression of TLR2 and TLR4, while no effect was observed on βGR or MR. Moreover, expression of TLR4 and TLR2 was associated with higher levels of in vitro production of TNF-α and IL-1, respectively. Production of IL-10 was also increased by ATF treatment, but we found no association between its production and the expression of Toll-like receptors. Conclusion Our results provided us with evidence that A. brasiliensis polysaccharides affect human monocytes probably through the modulation of Toll-like receptors.</p></div

Comparison of inflammatory cytokine profiles in plasma of patients undergoing otorhinological surgery with propofol or isoflurane anesthesia

Objective and design: The effects of anesthetics on cytokine release in patients without comorbidities who undergo minor surgery are not well defined. We compared inflammatory cytokine profiles in adult patients undergoing minimally invasive surgery who received isoflurane or propofol anesthesia. Methods: Thirty-four patients without comorbidities undergoing minor surgery were randomly assigned to receive an inhaled anesthetic (isoflurane; n = 16) or an intravenous anesthetic (propofol; n = 18). Blood samples were drawn before premedication and anesthesia (T1), 120 min after anesthesia induction (T2), and on the first post-operative day (T3). Plasma concentrations of interleukins (IL-) 1β, 6, 8, 10 and 12 and tumor necrosis factor (TNF)-α were measured using flow cytometry. Results: The pro-inflammatory cytokine IL-6 was increased in the isoflurane group at T2 and T3 compared to T1 (P < 0.01). In the propofol group, IL-6 and IL-8 were significantly increased at T3 compared to T1. However, there were no significant differences in cytokine concentrations between the isoflurane and propofol groups. Conclusion: An inflammatory response occurred earlier in patients who received an inhaled agent compared with an intravenous anesthetic, but no differences in plasma cytokine profiles were evident between isoflurane and propofol anesthesia in patients without comorbidities undergoing minimally invasive surgeries. © 2013 Springer Basel

Genotoxicity, cytotoxicity and gene expression in patients undergoing elective surgery under isoflurane anaesthesia

There are numerous studies reporting on the effects of inhalation anaesthesia in cells of exposed individuals but not much is known about the ability of isoflurane (ISF) to induce oxidative DNA damage. However, surgery is often associated with a temporary perioperative immunological alteration, and some volatile anaesthetics seem to contribute to a transient lymphocytopenia after surgery. We conducted a study to evaluate a possible genotoxic effect, including oxidative DNA damage, and apoptosis in peripheral lymphocytes of 20 patients American Society of Anaesthesiologists physical status I undergoing minor elective surgery lasting at least 120 min, under anaesthesia with ISF. We also investigated the expression of several genes in blood cells. Blood samples were collected at three time points: before anaesthesia (T(1)), 2 h after the beginning of anaesthesia (T(2)) and on the first post-operative day (T(3)). General DNA damage and oxidised bases (Fpg and endo III-sites) in blood lymphocytes were evaluated using the comet assay. Lymphocytes were phenotyped and apoptosis was evaluated by flow cytometry. In addition, expressions of hOGG1 and XRCC1, genes involved in DNA repair, and BCL2, a gene related to apoptosis, were assessed by quantitative real-time polymerase chain reaction. Results showed no statistically significant difference in the level of DNA damage and oxidised bases among the three sampling times. Anaesthesia with ISF did not increase the percentage of cells in early or late apoptosis in cytotoxic or helper T lymphocytes. Lower hOGG1 and BCL2 expressions were detected at T3 in comparison to the other two previous time points, and there was significantly lower expression of XRCC1 at T3 in relation to T2. In conclusion, the exposure to ISF did not result in genotoxicity and cytotoxicity in lymphocytes and in toxicogenomic effect in leukocytes, although DNA repair and apoptosis-related genes were down-regulated on the first post-operative day.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Analysis of Toll-Like Receptors, iNOS and Cytokine Profiles in Patients with Pulmonary Tuberculosis during Anti-Tuberculosis Treatment

Toll-like receptors (TLRs) play an important role in mycobacterial infection, although little is known about the roles of these receptors, cytokines and nitric oxide during anti-tuberculosis treatment. Our objective was to evaluate the mRNA and cell surface expression of TLR2 and TLR4; inducible nitric oxide synthase (iNOS) expression; and cytokine Th1, Th2 and Th17 profiles in pulmonary tuberculosis patients at different time points of anti-tuberculosis treatment. Peripheral blood mononuclear cells (PBMCs) were obtained from PPD+ healthy controls and from patients receiving anti-tuberculosis treatment. Gene expression quantification was performed by qPCR, cell surface expression was assessed using flow cytometry, and cytokine quantification was conducted using the CBA technique. The treated patients presented higher gene expression and higher numbers of receptors on the cell surface of lymphocytes and monocytes than did control individuals. IL-12 and IFN-gamma levels increased after the start of treatment, whereas TNF-alpha levels were reduced. TGF-beta presented the highest levels during treatment. IL-10 and IL-17 expression and production tended to increase during treatment. iNOS gene expression was reduced throughout treatment in patients. Our results suggest that anti-tuberculosis treatment modulates the immune response, inducing an increase in the expression of TLRs and pro-and anti-inflammatory cytokines to combat bacteria and reduce the inflammatory process.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Periodontal Tissue Engineering After Tooth Replantation

Background: Blood-derived products, platelet-poor plasma (PPP) and platelet-rich plasma (PRP), constitute an approach in the enhancement of tissue healing. PRP has also been used as a scaffold for bone marrow stem cells in tissue engineering. This study evaluates the effect of PPP, calcium chloride activated PRP (PRP/Ca), calcium chloride and thrombin-activated PRP (PRP/Thr/Ca), and bone marrow mononuclear cells and PRP/Ca (BMMCs/PRP/Ca) on the healing of replanted dog teeth.Methods: After 30 minutes of extraction, teeth were replanted with 1) no material (control); 2) PPP; 3) PRP/Ca; 4) PRP/Thr/Ca; or 5) BMMCs/PRP/Ca. Histologic, histomorphometric, and immunohistochemical analysis was assessed 120 days after replantation. Data from histomorphometric analysis were analyzed statistically (analysis of variance, Tukey; P < 0.05). Quantitative immunohistochemical analysis was analyzed by Kruskal-Wallis and Dunn post hoc test (P < 0.05).Results: Flow cytometry analysis showed 55.98% of CD34(+) and 32.67% of CD90/Thy-1 for BMMCs sample. BMMCs/PRP/Ca presented the largest areas of replacement resorption characterized by osseous ingrowth into cementum (P < 0.05), with intense immunomarcation for tartrate-resistant acid phosphatase. The PRP/Ca group also showed areas of replacement resorption with significant immunomarcation for osteopontin. PRP/Thr/Ca presented no replacement resorption. PPP showed areas of inflammatory resorption, with immunomarcation for tartrate-resistant acid phosphatase.Conclusions: The results suggest that platelets activated with thrombin play an important role in the healing of tissues after tooth replantation. Additional studies are necessary to test other materials, because PRP/Ca did not present an appropriate scaffold for undifferentiated cells in the treatment of avulsed teeth. J Periodontol 2011;82:758-766.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES