ABSTRACT
A gestação é um estado fisiológico que exige adaptações imunológicas para que transcorra normalmente. Nesse período a mãe e o feto apresentam uma relação imunológica, ou seja, a interface materno fetal. A enzima indoleamina 2,3 dioxigenase (IDO) desempenha um papel importante na tolerância materno fetal, por ser responsável pela metabolização do triptofano, impedindo por diversas vias a proliferação principalmente de linfócitos TCD8. Diversos tipos celulares estão presentes na interface materno fetal e vários deles podem expressar a IDO. Os leucócitos com perfil Th1 produzem uma citocina conhecida: o interferon γ que estimula a expressão da IDO em vários tipos celulares. Os linfócitos são divididos em subpopulações de acordo com sua função e fenótipo. Seus tipos incluem linfócitos T, linfócitos B e as células natural killer (NK). Hormônios também atuam nesse processo a progesterona que exerce função determinante sobre a resposta imunológica materna podendo alterar o prognóstico gestacional e o estrógeno essencial para a tolerância materno fetal e manutenção da prenhez. Dessa maneira este trabalho tem por objetivo principal identificar os linfócitos presentes na placenta bovina em cultivo que expressam IDO (linfócitos T, linfócitos B e células NK), frente a estimulação por progesterona, estrógeno e interferon γ nas diversas fases gestacionais utilizando a citometria de fluxo. Segundo os resultados no período de 67,5 a 77, 5 dias com a adição de interferon γ a expressão da enzima IDO aumentou discretamente nos linfócitos TCD3, TCD4, e diferente dos linfócitos T CD8 apresentaram uma elevada expressão da enzima (4,48 ± 2,12 - 8,65± 4,91)....
Pregnancy is a physiological state that requires immune adaptation in order to be successfully carried on. During this period, mother and fetus establish an immune tolerance status at the maternal fetal interface. Indoleamine 2,3-dioxygenase (IDO) plays an important role in maternal-fetal tolerance by metabolizing tryptophan, impairs by several pathways, mainly T CD8 cells proliferation. Several cell types are present in the maternal fetal interface and several of them can express IDO. Leucocytes with Th1 produce a cytokine known as interferon γ that stimulates the expression of IDO in several cell types. Lymphocytes are divided into sub-populations according to their function and phenotype: T lymphocytes, B lymphocytes and natural killer cells (NK). Hormones also involved in this process where progesterone exerts decisive role on maternal immune response that may change gestational outcome and estrogen is essential for fetal maternal tolerance and maintenance of pregnancy. Therefore, the main objective of this study was to identify lymphocytes in the bovine placental cell culture that are sensitive to progesterone, estrogen and interferon γ, IDO expression in various gestational stages using flow cytometry. According to the results in the gestational period from 67.5 to 77.5 days with the addition of interferon γ expression IDO was slightly increased in TCD3 lymphocytes, CD4, and differently from the other T cells CD8 displayed an higher expression of the enzyme (4.48±2.12 to 8.65±4.91)...
Subject(s)
Animals , Female , Pregnancy , Cattle , Immunophenotyping/veterinary , /analysis , Lymphocytes/classification , Lymphocytes/immunology , Placenta , Placenta/physiology , Immune Tolerance/physiology , B-Lymphocytes , Estrogens/analysis , Interferon-gamma/analysis , Killer Cells, Natural , Progesterone/analysis , T-LymphocytesABSTRACT
The umbilical cord blood (UCB) is an important source of pluripotent stem cells, which motivated researches on ontogeny and transplantation. The morphological characterization of umbilical cord cells is the first step to establish subsequent experiments on these areas. Although some information on humans can be found, no data on UCB is available for bovines. Therefore, this work is the first attempt to conduct an ultrastructural characterization of bovine umbilical cord blood. Blood was collected from the umbilical cord of twenty fetuses by punction of the umbilical vein. Samples were processed for whole leucocytes observation by centrifugation and the buffy coat was collected. Cells were washed and pelleted and prepared according to the standard protocol of the transmission electron microscopy. The presence of cells with morphologic characteristics compatible with the precursors from the erythrocytic, neutrophilic, eosinophilic, basophilic, and lymphocytic lineages was observed. Atypical cells with peculiar morphological features, strongly similar to apoptotic cells, were seen. Bovine neutrophils with three types of cytoplasmic granules were also found in the blood. The ultrastructural characteristics of observed bovine UCB cells where similar to those found in other species, suggesting that bovines could possibly constitute an experimental model for approaches on UCB cells research.
O sangue de cordão umbilical (SCU) é uma importante fonte de células progenitoras pluripotentes, que motiva pesquisas em ontogenia e transplantes. A caracterização morfológica das células de cordão umbilical é o primeiro passo para se estabelecer experimentos subsequentes nessas áreas. Embora algumas informações sobre SCU em humanos possam ser encontradas, não existe nenhuma informação disponível sobre elas em bovinos. Portanto, este trabalho é a primeira tentativa de se conduzir uma caracterização ultra-estrutural do sangue de cordão umbilical bovino. O sangue foi coletado do cordão umbilical de 20 fetos por punção da veia umbilical. As amostras foram processadas para observação dos leucócitos totais por centrifugação pela coleta do botão leucocitário. As células foram lavadas, peletizadas e preparadas de acordo com protocolo padrão para microscopia eletrônica de transmissão. A presença de células com características morfológicas compatíveis com precursores das linhagens eritrocítica, neutrofílica, eosinofílica, basofílica e linfocítica foram observadas. Células atípicas com características morfológicas peculiares muito semelhantes a células em apoptose foram observadas. No sangue do cordão umbilical também foi encontrado neutrófilos bovinos apresentando três tipos de grânulos citoplasmáticos. As características ultraestruturais do SCU bovino foram semelhantes às encontradas em outras espécies, sugerindo que esta espécie possa servir como modelo experimental para abordagens em pesquisa sobre sangue de cordão umbilical.
Subject(s)
Animals , Blood Cell Count/methods , Blood Cell Count/veterinary , Umbilical Cord/cytology , Umbilical Cord/ultrastructure , CattleABSTRACT
The amastigogenesis primary of T. cruzi occurs naturally when metacyclic trypomastigotes transform into amastigotes within the cells of the mammalian host. The in vitro study of the macromolecular changes that occur over several days during the transformation process should provide significant indications of how the parasite adapts to the mammalian host environment. We show here that metacyclic trypomastigotes pre-incubated at 37 degrees C in a protein-rich medium reach a high degree of transformation to amastigotes when re-incubated in the fresh medium. Giemsa-stained smears show that during the pre-incubation phase, the metacyclic trypomastigotes undergo lengthening at the posterior end and a thinning out of the entire body. SDS-PAGE analysis of polypeptides and glycopeptides or Western blot with stage-specific antisera analyses indicate that the in vitro primary amastigogenesis is associated with abrupt changes in protein, glycoprotein, and stage-specific antigens that occur simultaneously during the first 24 hours of pre-incubation. Since the differentiating system consists of a rich media at 37 degrees C, temperature and medium constitution must trigger a macromolecular differentiation to amastigotes that precedes the morphological transformation by several days. This transformation is associated with the rearrangement of stage-specific antigens and takes place when the culture medium is changed.