Imunofenotipagem dos linfócitos positivos para indoleamina 2,3 dioxigenase (IDO) em cultura de células de placenta bovina

Abstract

RESUMO.-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 lin- 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). In the period from 92.5 to 172. 5 days the CD4 lymphocytes, CD8 and TCD25 showed a significant decrease of IDO expression (p<0.05). At the final stages between 195 and 222, 5 days TCD3 lymphocytes, CD4 and BCD25 increased expression when subjected to interferon γ supplementation; however, CD8 T cells and NK cells showed no significant changes. Based on the results presented we can conclude that all cell types were able to express IDO by supplementation with interferon γ, and that T CD8 lymphocyte showed an highly significant increase of IDO expression, whereas estrogen increased the expression of IDO only in B lymphocytes (CD25), and progesterone decreased enzyme expression in T lymphocytes (CD3 and CD4) and in NK cells. These results suggest a regulatory mechanism of the immunological system by steroidal hormones during gestation, particularly by modulating IDO expression.

Efeito da suplementação do homeopático Curso Zero® na prevenção e tratamento da diarreia e no desempenho de bezerros em aleitamento

“…Em bovinos, a placenta é classificada como sindesmocorial ou sinepiteliocorial, pois o epitélio coriônico do feto entra diretamente em contato com os tecidos uterinos maternos, havendo invasão de células fetais no tecido materno em pequena escala, mas havendo a necessidade da tolerância imunológica materna para que não aconteça a rejeição fetal (CATOIA et al, 2016).…”

Avaliação da transferência de imunidade passiva em bezerros colostrados com colostro materno ou diferentes doses de substituto de colostro e seus efeitos na saúde e desempenho

“…Os substitutos do colostro podem ser a única fonte de nutrição para recém-nascidos, pois contêm mais de 100 g de IgG por dose, possibilitando que os bezerros alcancem IgG sérica > 10g/L ao final do período de colostragem, além de proteínas, vitaminas e minerais similares as concentrações encontradas no colostro materno (Quigley, 2002 (Catoia et al, 2016).…”