Linfócitos e macrófagos são os principais tipos de leucócitos envolvidos no processo de tolerância materno-fetal. Os linfócitos são divididos em sub-populações de acordo com sua função e fenótipo, apesar de serem morfologicamente semelhantes. Seus tipos incluem os linfócitos T, linfócitos B e natural killers (NK). Macrófagos são células que derivam da migração dos monócitos sangüíneos para o tecido. Na placenta, os macrófagos desempenham um papel importante na regulação da apoptose, prejudicial para o desenvolvimento do embrião, e no processo de apresentação antigênica. Pouco se sabe sobre esses leucócitos na placenta bovina, como sua quantidade e onde estão presentes. Desta maneira, este trabalho tem por objetivo principal identificar as populações de linfócitos e macrófagos presentes na placenta bovina utilizando marcadores específicos e citometria de fluxo. Neste estudo, foram utilizados amostras de placentônios e região intercaruncular de vacas nos três diferentes trimestres da gestação (cinco animais de cada trimestre). As suspensões celulares obtidas foram incubadas com anticorpos monoclonais anti-CD3, anti-CD8, anti-(CD14), e anti-CD335 (uNK) e avaliados pela citometria de fluxo. No placentônio, no primeiro trimestre da gestação, a porcentagem média de células marcadas CD3+ foi de 2,37%, CD8+, 2,39%, CD14+, 1,16% e CD335+, 0,78%. Para a região intercaruncular, a porcentagem de células CD3+ foi 3,43%, 4,41% CD8+, CD14+ 3,91% e CD335+ 0,56%. No segundo trimestre gestacional, o placentônio apresentou 0,63% de células positivas para CD3+, 0,62% para CD8+, 0,34% para CD14+ e 0,55% para CD335+. Na região interplacentomal a porcentagem de células marcadas com CD3+ foi 1,59%, 1,25% para CD8+, 0,38% para CD14+ e 0,39% para CD335+. No terceiro trimestre gestacional, o placentônio apresentou 0,72% de células marcadas para CD3+, 0,75% para CD8+, 1,05% para CD14+ e 0,77% para CD335+. Na região interplacentomal a porcentagem de células marcadas para CD3+ foi 1,59%, 1,50% para CD8+, 0,60% para CD14+ e 0,48% para CD335+. Com base nos resultados apresentados, podemos concluir que a população de leucócitos na 11 placenta bovina é menos numerosa quando comparada às outras espécies como camundongos e humanos, provavelmente pelo tipo de placenta sinepiteliocorial que constitui uma barreira significativa para o sistema imunológico materno, diminuindo drasticamente a exposição do concepto a ele. / Lymphocytes and macrophages are the main types of leukocytes involved in the maternal-fetal process of tolerance. Lymphocytes may be divided in subpopulations according to their function and phenotype, although being morphologically similar. Its types include the T lymphocyte, B lymphocyte and natural killers (NK). Macrophages are cells that derive from the migration of blood monocytes to the tissue. In the placenta, macrophages play an important role in the regulation of apoptosis which is deleterious to the development of the embryo and in the process of antigen presentation. There are very few references regarding the presence and quantity of leukocytes in the bovine placenta, therefore this project aims to identify lymphocytes and macrophages populations in the bovine placenta by using specific markers and flow cytometry. In this study placentomes and interplacentomal regions of cows in the three trimesters of pregnancy (five animals of each trimester) were used. Cells were incubated with the following monoclonal antibodies: anti-CD3, anti-CD8, anti-CD14,) and anti-CD335 (uNK) and evaluated by flow cytometry. In the first trimester of pregnancy, for the placentome, the average percentage of cells marked CD3+ was 2.37%, CD8+ 2.39%, , CD14+ 1.16% and CD335+ 0.78%. For the interplacentomal region the percentage of CD3+ was 3.43%, CD8+ 4.41%, CD14+ 3.91%, and CD335+ 0.56%. In second trimester of pregnancy, the placentome presented 0.63% of cells marked with CD3+, 0.62% of CD8+, 0.34% of CD14+ and 0.55% of CD335+. In the interplacentomal region the percentage of cells marked with CD3+ was of 1.59%, 1.25% of CD8+, 0.38% of CD14% and 0.39% of CD335+. In the third trimester of pregnancy, the placentomes had presented 0.72% of cells marked with CD3+, 0.75% of CD8+, 1.05% of CD14+ and 0.77% of CD335+. In the interplacentomal region the percentage of cells marked with CD3+ was of 1.59%, 1.50% of CD8+, 0.60% of CD14+ and 0.48% of CD335+. Based on the presented results, we can conclude that the leukocytes population in the bovine placenta is less 13 numerous than those described for other species like mouse and human, probably because it is a sinepithelial type placenta that constitutes a significant barrier to the maternal immunological system, diminishing drastically the conceptus antigen exposition to it.

Linfócitos e macrófagos são os principais tipos de leucócitos envolvidos no processo de tolerância materno-fetal. Os linfócitos são divididos em sub-populações de acordo com sua função e fenótipo, apesar de serem morfologicamente semelhantes. Seus tipos incluem os linfócitos T, linfócitos B e natural killers (NK). Macrófagos são células que derivam da migração dos monócitos sangüíneos para o tecido. Na placenta, os macrófagos desempenham um papel importante na regulação da apoptose, prejudicial para o desenvolvimento do embrião, e no processo de apresentação antigênica. Pouco se sabe sobre esses leucócitos na placenta bovina, como sua quantidade e onde estão presentes. Desta maneira, este trabalho tem por objetivo principal identificar as populações de linfócitos e macrófagos presentes na placenta bovina utilizando marcadores específicos e citometria de fluxo. Neste estudo, foram utilizados amostras de placentônios e região intercaruncular de vacas nos três diferentes trimestres da gestação (cinco animais de cada trimestre). As suspensões celulares obtidas foram incubadas com anticorpos monoclonais anti-CD3, anti-CD8, anti-(CD14), e anti-CD335 (uNK) e avaliados pela citometria de fluxo. No placentônio, no primeiro trimestre da gestação, a porcentagem média de células marcadas CD3+ foi de 2,37%, CD8+, 2,39%, CD14+, 1,16% e CD335+, 0,78%. Para a região intercaruncular, a porcentagem de células CD3+ foi 3,43%, 4,41% CD8+, CD14+ 3,91% e CD335+ 0,56%. No segundo trimestre gestacional, o placentônio apresentou 0,63% de células positivas para CD3+, 0,62% para CD8+, 0,34% para CD14+ e 0,55% para CD335+. Na região interplacentomal a porcentagem de células marcadas com CD3+ foi 1,59%, 1,25% para CD8+, 0,38% para CD14+ e 0,39% para CD335+. No terceiro trimestre gestacional, o placentônio apresentou 0,72% de células marcadas para CD3+, 0,75% para CD8+, 1,05% para CD14+ e 0,77% para CD335+. Na região interplacentomal a porcentagem de células marcadas para CD3+ foi 1,59%, 1,50% para CD8+, 0,60% para CD14+ e 0,48% para CD335+. Com base nos resultados apresentados, podemos concluir que a população de leucócitos na 11 placenta bovina é menos numerosa quando comparada às outras espécies como camundongos e humanos, provavelmente pelo tipo de placenta sinepiteliocorial que constitui uma barreira significativa para o sistema imunológico materno, diminuindo drasticamente a exposição do concepto a ele. / Lymphocytes and macrophages are the main types of leukocytes involved in the maternal-fetal process of tolerance. Lymphocytes may be divided in subpopulations according to their function and phenotype, although being morphologically similar. Its types include the T lymphocyte, B lymphocyte and natural killers (NK). Macrophages are cells that derive from the migration of blood monocytes to the tissue. In the placenta, macrophages play an important role in the regulation of apoptosis which is deleterious to the development of the embryo and in the process of antigen presentation. There are very few references regarding the presence and quantity of leukocytes in the bovine placenta, therefore this project aims to identify lymphocytes and macrophages populations in the bovine placenta by using specific markers and flow cytometry. In this study placentomes and interplacentomal regions of cows in the three trimesters of pregnancy (five animals of each trimester) were used. Cells were incubated with the following monoclonal antibodies: anti-CD3, anti-CD8, anti-CD14,) and anti-CD335 (uNK) and evaluated by flow cytometry. In the first trimester of pregnancy, for the placentome, the average percentage of cells marked CD3+ was 2.37%, CD8+ 2.39%, , CD14+ 1.16% and CD335+ 0.78%. For the interplacentomal region the percentage of CD3+ was 3.43%, CD8+ 4.41%, CD14+ 3.91%, and CD335+ 0.56%. In second trimester of pregnancy, the placentome presented 0.63% of cells marked with CD3+, 0.62% of CD8+, 0.34% of CD14+ and 0.55% of CD335+. In the interplacentomal region the percentage of cells marked with CD3+ was of 1.59%, 1.25% of CD8+, 0.38% of CD14% and 0.39% of CD335+. In the third trimester of pregnancy, the placentomes had presented 0.72% of cells marked with CD3+, 0.75% of CD8+, 1.05% of CD14+ and 0.77% of CD335+. In the interplacentomal region the percentage of cells marked with CD3+ was of 1.59%, 1.50% of CD8+, 0.60% of CD14+ and 0.48% of CD335+. Based on the presented results, we can conclude that the leukocytes population in the bovine placenta is less 13 numerous than those described for other species like mouse and human, probably because it is a sinepithelial type placenta that constitutes a significant barrier to the maternal immunological system, diminishing drastically the conceptus antigen exposition to it.

A indoleamina 2,3-dioxigenase (IDO) é uma enzima, produzida pelas células trofoblásticas e, por sua capacidade de catabolizar o triptofano, inibe a proliferação das células T maternas, participando desta forma como importante mecanismo da tolerância materno-fetal. Contudo, pouco se sabe se a ação da IDO é influenciada por outras substâncias presentes no micro-ambiente uterino e, por esta razão, formulou-se a hipótese de que esta enzima poderia ter sua ação alterada nesse contexto e, desta forma, avaliou-se o comportamento da expressão da IDO frente à adição de alguns desses componentes presentes no útero gestante. Neste trabalho, células uterinas, de placentas e de embriões de ratas e camundongos fêmeas prenhes e não prenhes foram mantidas em cultivo e a elas adicionadas estradiol, progesterona, interferon , triptofano e 1-metil-D- triptofano, avaliando-se a expressão da IDO pela técnica de citometria de fluxo nos períodos de 4, 24 e 48 horas. Os resultados demonstraram que as diferenças mais significativas na expressão da IDO entre as ratas prenhes e não prenhes, foram observadas após a adição de progesterona (19,24%), interferon (11.22%) e triptofano (23,53%), nas ratas prenhes. Já nos camundongos fêmeas prenhes e não prenhes, as maiores expressões de IDO foram observadas no primeiro grupo pela adição de progesterona (11,33%), estradiol (9,98%) e interferon (21,78%). Considerando esses resultados, podemos concluir que a expressão da IDO pelas células uterinas, placentárias e embrionárias em cultivo sofre influência dos fatores testados, o que permite novas hipóteses para melhor compreensão da participação dessa enzima na tolerância materno-fetal, particularmente em relação a sua interação com hormônios e citocinas presentes no útero gestante. Além disso, poderá colaborar na elaboração de possíveis tratamentos de enfermidades, relacionadas à manutenção e sucesso da gestação onde haja envolvimento do sistema imunológico materno e dos mecanismos de tolerância. / Indoleamine 2,3-dioxygenase (IDO) is an enzyme produced by trophoblast cells and due to its ability to catabolize tryptophan, inhibits the proliferation of maternal T cells, thus playing an important role as one of the mechanisms of maternal-fetal tolerance. However, little is known whether the action of IDO is influenced by substances present in the pregnant uterine microenvironment. This study evaluated the behavior of the IDO expression in cultured placental and embryonic cells from mice and rats in face of the addition of estradiol, progesterone, interferon, tryptophan and 1-methyl-D-tryptophan, by flow cytometry, at 4, 24 and 48 hours periods. The results showed that high expressions of IDO were observed in pregnant rats cells after the addition of progesterone (19.24%), interferon (11.22%) and tryptophan (23.53%). In mice, high expressions of IDO were observed in the pregnant group cells by the addition of progesterone (11.33%), estradiol (9.98%) and interferon- (21.78%). Considering these results, we may conclude that the expression of IDO by cultured placental and embryonic cells from mice and Wistar rats is indeed influenced by factors present in pregnant uterus, which provides additional information to better understand IDO role in the maternal-fetal tolerance, particularly on its interactions with reproductive hormones and cytokines. Additionally, it may contribute to the establishment of possible treatments for pregnancy-losses related to the maternal immune system response and mechanisms of tolerance.

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 &#1091; 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 (uNK). 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 &#1091; 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 &#1091; a expressão da enzima IDO aumentou discretamente nos linfócitos TCD3, TCD4, e diferentemente dos linfócitos T CD8 apresentaram uma elevada expressão da enzima (4,48 ± 2,12 8,65± 4,91). No período de 92,5 a 172, 5 dias os linfócitos TCD4, TCD8 e TCD25 apresentaram uma diminuição significativa da IDO. No período final da gestação entre 195 a 222, 5 dias, os linfócitos TCD3, TCD4 e os BCD25 aumentaram a expressão da IDO quando submetidos ao interferon &#1091;, no entanto, os linfócitos T CD8 e as células NK não apresentaram alterações significativas. Com base nos resultados apresentados podemos concluir que todos os tipos celulares foram capazes de expressar a IDO mediante a suplementação com interferon &#1091;, sendo que o linfócito T CD8 apresentou uma diferença bastante significativa quanto ao aumento da IDO, já o estrógeno elevou a expressão da IDO somente nos linfócitos B (CD25) e a progesterona diminuiu a expressão da enzima nos linfócitos T (CD3 e CD4) e nas células NK / Pregnancy is a physiological state that requires immune adaptations in order to be successfully carried on. During this period the mother and the fetus establish an immuno 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 present in the maternal fetal interface and several of them can express IDO. Leukocytes with Th1 produce a cytokine known: interferon &#1091; 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 (uNK). Hormones also involved in this process where progesterone exerts decisive role on maternal immune response that may change gestational outcomes and estrogen is essential for fetal maternal tolerance and maintenance of pregnancy. Therefore this work main objective was to identify lymphocytes present in the bovine placental cells culture that were sensitive to progesterone, estrogen and interferon &#1091; stimulation regarding their IDO expression in various gestational stages using flow cytometry. According to the results in the gestation period from 67,5 to 77,5 days, with the addition of interferon &#1091;. IDO expression was slightly increased in TCD3 lymphocytes, CD4, and differently from the other T cells CD8 displayed a higher expression of the enzyme (4.48 ± 2.12 to 8.65 ± 4.91). In the period from 92.5 to 172, 5 days CD4 lymphocytes, CD8 and TCD25 showed a significant decrease of IDO expression (p<0,05). At the final gestacional stages between 195-222 5 days, TCD3 lymphocytes, CD4 and BCD25 increased expression when subjected to interferon &#1091; 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 &#1091;, and that T CD8 lymphocyte showed a highly significant increasing of IDO expression, whereas estrogen increased the expression of IDO only in B lymphocytes (CD25) and progesterone decreased the enzyme expression in T lymphocytes (CD3 and CD4) and in NK cells

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 &#1091; 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 (uNK). 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 &#1091; 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 &#1091; a expressão da enzima IDO aumentou discretamente nos linfócitos TCD3, TCD4, e diferentemente dos linfócitos T CD8 apresentaram uma elevada expressão da enzima (4,48 ± 2,12 8,65± 4,91). No período de 92,5 a 172, 5 dias os linfócitos TCD4, TCD8 e TCD25 apresentaram uma diminuição significativa da IDO. No período final da gestação entre 195 a 222, 5 dias, os linfócitos TCD3, TCD4 e os BCD25 aumentaram a expressão da IDO quando submetidos ao interferon &#1091;, no entanto, os linfócitos T CD8 e as células NK não apresentaram alterações significativas. Com base nos resultados apresentados podemos concluir que todos os tipos celulares foram capazes de expressar a IDO mediante a suplementação com interferon &#1091;, sendo que o linfócito T CD8 apresentou uma diferença bastante significativa quanto ao aumento da IDO, já o estrógeno elevou a expressão da IDO somente nos linfócitos B (CD25) e a progesterona diminuiu a expressão da enzima nos linfócitos T (CD3 e CD4) e nas células NK / Pregnancy is a physiological state that requires immune adaptations in order to be successfully carried on. During this period the mother and the fetus establish an immuno 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 present in the maternal fetal interface and several of them can express IDO. Leukocytes with Th1 produce a cytokine known: interferon &#1091; 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 (uNK). Hormones also involved in this process where progesterone exerts decisive role on maternal immune response that may change gestational outcomes and estrogen is essential for fetal maternal tolerance and maintenance of pregnancy. Therefore this work main objective was to identify lymphocytes present in the bovine placental cells culture that were sensitive to progesterone, estrogen and interferon &#1091; stimulation regarding their IDO expression in various gestational stages using flow cytometry. According to the results in the gestation period from 67,5 to 77,5 days, with the addition of interferon &#1091;. IDO expression was slightly increased in TCD3 lymphocytes, CD4, and differently from the other T cells CD8 displayed a higher expression of the enzyme (4.48 ± 2.12 to 8.65 ± 4.91). In the period from 92.5 to 172, 5 days CD4 lymphocytes, CD8 and TCD25 showed a significant decrease of IDO expression (p<0,05). At the final gestacional stages between 195-222 5 days, TCD3 lymphocytes, CD4 and BCD25 increased expression when subjected to interferon &#1091; 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 &#1091;, and that T CD8 lymphocyte showed a highly significant increasing of IDO expression, whereas estrogen increased the expression of IDO only in B lymphocytes (CD25) and progesterone decreased the enzyme expression in T lymphocytes (CD3 and CD4) and in NK cells

Glycodelin, a homodimeric glycoprotein belonging to the lipocalin superfamily, is synthesised predominantly by the cells of the reproductive system of certain primates including humans. Of the four different known glycoforms of the molecule, glycodelin A (GdA), secreted by the glandular epithelial cells of the endometrium in response to progesterone, is involved in the immunosuppression of the maternal immune response to the semi-allograft fetus. GdA secretion onsets few days after ovulation. In the absence of fertilization, GdA levels drop, but subsequent to a successful fertilization, the concentrations peak till the 12th week of pregnancy and fall steadily to low levels. The importance of GdA has been implicated in implantation, endometrial receptivity, trophoblast invasion and differentiation, and modulating the functions of almost all immune cells. GdA has profound influence on the activity of T cells. It inhibits the proliferation of T cells, induces apoptosis in activated T cells, inhibits the IL-2 production and leads to skewing of the Th-1/Th-2 balance towards Th-2 type of immune response. Cytotoxic T lymphocytes are more resistant to the induction of apoptosis by GdA, but, it suppresses their cytolytic activity Additionally, GdA induces apoptosis in monocytes and natural killer (NK) cells, inhibits the proliferation of B cells and induces tolerogenic phenotype in dendritic cells. Clinical studies showing that women undergoing recurring spontaneous abortions have low levels of GdA supports its role in prevention of fetus rejection. The immunomodulatory activity of Gd resides in the protein backbone, however, apart from GdA and GdF which have similar oligosaccharide chains, other glycoforms do not possess this activity. Glycosylation seems to dictate the stability, folding and activity of Gd. In absence of glycosylation, the expression of the recombinant Gd is compromised and the protein is improperly folded while over-mannosylation of Gd impairs its immunomodulatory function. Additionally, sialylation seen on the glycan chain regulates the activity. Therefore, in order to obtain adequate amounts of active recombinant Gd (rGd), expression of the protein was attempted in three different systems, insect, yeast and bacteria (Chapter 1). In all of the described systems, the rGd protein was found apoptotically active. The protein expressed in the Sf21 insect cells was demonstrated to be differentially glycosylated compromising the activity. Hence, a genetically modified yeast strain, Pichia pastoris SuperMAN5 was explored for expression. Though presence of a single glycosylated protein species was observed in small-scale cultures, similar to the case of Sf21 cell expression, differentially glycosylated proteins were detected in large-scale fermentation and even the yield was low. Eventually, mutant Gd, modified to increase the stability and aid in proper protein folding, was expressed in E.coli and demonstrated to be able to induce apoptosis in Jurkat cells (T cell leukemia cell line). This active rGd was used for further studies. The immunomodulatory function of GdA during pregnancy protects the semi-allograft fetus from rejection by the maternal immune system. In the process, GdA tweaks the T cell immune response from pro-inflammatory to anti-inflammatory in a specific and localized manner. Allograft rejection seen during mis-match transplantations is basically a pro-inflammatory condition which is mediated by the activation of cellular immune response, NK cell cytotoxicity and antibody-dependent immune response, the same processes that are suppressed for a successful pregnancy. Chapter 2 discusses whether it is feasible to use Gd to prevent allograft rejection. Killing of target graft cells by the cytotoxic T lymphocytes (CTLs) predominantly presides acute graft rejection. GdA treatment has been shown to suppress the cytotoxicity of in vitro generated CTLs. On this basis, the earlier study was translated to in vivo conditions by establishing an allograft nude mouse model. The tumor rejection mediated by the action of in vitro generated cytotoxic alloactivated PBMCs in the nude mouse imitated the allograft rejection. A heterogenous population of immune cells with the predominance of CTLs was chosen to accommodate a more interactive immune response in the tumor microenvironment and enabled the study of other cells which may contribute to the rejection. Reactivation and proliferation of CD4+ and CD8+ T cells following their infiltration in the tumor validated our hypothesis. On treatment with rGd, the cytotoxicity of the alloactivated PBMCs was suppressed, thereby inhibiting the tumor rejection in the nude mouse. Real time PCR analysis showed that rGd treatment was able to affect the functions of the immune cells in vivo. It decreased the T cell population most probably by inducing apoptosis. As expected, the reduction was more prominent in case of CD4+ T cells than CD8+ T cells. The their expression of key molecules responsible for the cytotoxicity such as IL-2, granzyme B and EOMES, was observed to be downregulated by rGd. Concomitantly, decreased levels of pro-inflammatory cytokines, TNFα and IL-6 were also seen. Expression of Foxp3, marker for regulatory T cells, was upregulated in the tumor infiltrating immune cells suggesting an expansion of the concerned population upon rGd treatment. Overall, rGd seems to suppress the cellular immune response to the tumor by modulating the T cell population and their functions. Since, T cell-dependent immune response is central to allograft rejection, the ability of rGd to regulate it could be of therapeutic use in the management of allograft rejection. NK cells are essential for the maintenance of pregnancy, evident from their abundance (70% of total leukocytes) at the first trimester decidua. The third chapter focuses on how Gd regulates the NK cell function. The cytokine production from CD56bright subset of NK cells and their interaction with the HLA antigens expressed by the trophoblast cells helps in creating a favourable environment for the growth of the fetus. It is important to note that the NK cell population present in the decidua exclusively express Gd, implicating a role of Gd in their differentiation from the peripheral CD56bright cells. However, an increased number of CD56dimCD16+ cells in the peripheral blood dictates a negative outcome for the pregnancy. The study, presented in Chapter 3, demonstrated that rGd treatment induces caspase-dependent apoptosis in the activated CD56dimCD16+ cells and reduces their cytotoxicity by downregulating granzyme B and IFNγ production. Similar effect of rGd is also seen on the NKT cells characterised as CD3+CD56dimCD16-. Furthermore, in YT-Indy cells, an activated NK cell line, it was shown that the induction of apoptosis by rGd involves Ca2+ signalling which could explain why Gd affects activated immune cells only. This study therefore reinforces the role of Gd in modulating the NK cell activity during pregnancy. Cytotoxicity of NK and NKT cells also plays an important role during allograft rejection. Decrease in the mRNA levels of CD56 upon rGd treatment in the allograft mouse model indicates that the effect of Gd on NK cells observed in cell culture system can be translated to in vivo conditions. In conclusion, suppression of the cellular immune response and NK cell mediated cytotoxicity by rGd could potentiate its’ probable use in the management of allograft rejection. .

A indoleamina 2,3-dioxigenase (IDO) é uma enzima, produzida pelas células trofoblásticas e, por sua capacidade de catabolizar o triptofano, inibe a proliferação das células T maternas, participando desta forma como importante mecanismo da tolerância materno-fetal. Contudo, pouco se sabe se a ação da IDO é influenciada por outras substâncias presentes no micro-ambiente uterino e, por esta razão, formulou-se a hipótese de que esta enzima poderia ter sua ação alterada nesse contexto e, desta forma, avaliou-se o comportamento da expressão da IDO frente à adição de alguns desses componentes presentes no útero gestante. Neste trabalho, células uterinas, de placentas e de embriões de ratas e camundongos fêmeas prenhes e não prenhes foram mantidas em cultivo e a elas adicionadas estradiol, progesterona, interferon , triptofano e 1-metil-D- triptofano, avaliando-se a expressão da IDO pela técnica de citometria de fluxo nos períodos de 4, 24 e 48 horas. Os resultados demonstraram que as diferenças mais significativas na expressão da IDO entre as ratas prenhes e não prenhes, foram observadas após a adição de progesterona (19,24%), interferon (11.22%) e triptofano (23,53%), nas ratas prenhes. Já nos camundongos fêmeas prenhes e não prenhes, as maiores expressões de IDO foram observadas no primeiro grupo pela adição de progesterona (11,33%), estradiol (9,98%) e interferon (21,78%). Considerando esses resultados, podemos concluir que a expressão da IDO pelas células uterinas, placentárias e embrionárias em cultivo sofre influência dos fatores testados, o que permite novas hipóteses para melhor compreensão da participação dessa enzima na tolerância materno-fetal, particularmente em relação a sua interação com hormônios e citocinas presentes no útero gestante. Além disso, poderá colaborar na elaboração de possíveis tratamentos de enfermidades, relacionadas à manutenção e sucesso da gestação onde haja envolvimento do sistema imunológico materno e dos mecanismos de tolerância. / Indoleamine 2,3-dioxygenase (IDO) is an enzyme produced by trophoblast cells and due to its ability to catabolize tryptophan, inhibits the proliferation of maternal T cells, thus playing an important role as one of the mechanisms of maternal-fetal tolerance. However, little is known whether the action of IDO is influenced by substances present in the pregnant uterine microenvironment. This study evaluated the behavior of the IDO expression in cultured placental and embryonic cells from mice and rats in face of the addition of estradiol, progesterone, interferon, tryptophan and 1-methyl-D-tryptophan, by flow cytometry, at 4, 24 and 48 hours periods. The results showed that high expressions of IDO were observed in pregnant rats cells after the addition of progesterone (19.24%), interferon (11.22%) and tryptophan (23.53%). In mice, high expressions of IDO were observed in the pregnant group cells by the addition of progesterone (11.33%), estradiol (9.98%) and interferon- (21.78%). Considering these results, we may conclude that the expression of IDO by cultured placental and embryonic cells from mice and Wistar rats is indeed influenced by factors present in pregnant uterus, which provides additional information to better understand IDO role in the maternal-fetal tolerance, particularly on its interactions with reproductive hormones and cytokines. Additionally, it may contribute to the establishment of possible treatments for pregnancy-losses related to the maternal immune system response and mechanisms of tolerance.

No description available.

O tubarão-azul (Prionace glauca) é uma espécie que apresenta desenvolvimento vivíparo placentário em que o saco vitelino se desenvolve ao longo da gestação tornando-se uma placenta que executa função matrotrófica. A Indoleamina 2,3-dioxigenase (IDO) é uma proteína encontrada em mamíferos nos quais participa, além de outras funções, da tolerância materno-fetal, sendo também encontrada em peixes ósseos. Assim, a proposta deste trabalho foi verificar a expressão da IDO na interface materno-fetal de Prionace glauca e descrever sua localização. Para tanto, material placentário/uterino e embriológico de três fases distintas da gestação (pré-placenta, meia gestação e fim da gestação) de fêmeas de P. glauca foram coletados e processados para a imuno-histoquímica. Os resultados mostraram a presença da IDO ao longo do desenvolvimento do saco vitelino/placenta, na ectoderme nas três fases e na endoderme apenas nas duas primeiras fases. No epitélio uterino observou-se a marcação da IDO nas duas últimas fases. Esses tecidos de interface seriam locais de maior contato entre a mãe e o concepto, fato que poderia levar à indução de uma resposta imunológica contra o concepto semi-alogenêico. A soma destes fatores poderia contribuir como um indício de uma possível atuação da IDO como mecanismo da tolerância materno-fetal na interface placentária de Chondrichtyes, como relatado em mamíferos eutérios / The blue shark (Prionace glauca) is a viviparous placentary species in which the yolk sac develops along pregnancy turning into a placenta with a matrotrofic role. The indoleamine 2 3-dioxygenase (IDO) is a protein usually described in mammals, which, among other functions, participates on the maternal-fetal tolerance process. Although it has also been reported in bony fish, no information is available regarding its function. Therefore, the purpose of this study was to investigate the expression of IDO in blue shark maternal-fetal interface and describe its distribution. Thus, placental / uterine and embryonic materials from three different stages (pre-placenta, middle and late gestation) of pregnant P. glauca females were processed for immunohistochemistry. The results showed IDO labelling during the yolk sac / placenta development in ectoderm along the three development phases and at endoderm only at phases I and II. In uterine epithelium, IDO was observed in the last two phases. These interface tissues are major contact areas between the mother ant the conceptus, that would induce an immunological response against the semialogeneic conceptus.The sum of these factors may contribute as an indication to the possible IDO role as a mechanism of maternal-fetal tolerance in Chondrichtyes placentary interface, as described in eutherian mammals

A gestação confere ao organismo materno uma série de mudanças e desafios, envolvendo especialmente seu sistema imunológico. O feto, do ponto de vista imunológico, é comparado a um enxerto semi-alogenêico, pois expressa moléculas do complexo de histocompatibilidade principal (MHC) paterno, considerado não próprio ao organismo materno, capaz de desencadear uma resposta imunológica no ambiente intrauterino. Porém, durante todo o período gestacional, o organismo materno reconhece o embrião sem uma resposta imunológica contra sua permanência no útero, estabelecendo-se uma tolerância materno-fetal. Vários mecanismos contribuem para esse estado tolerogênico, como a atividade da enzima indoleamina 2,3-dioxigenase (IDO). A IDO promove o catabolismo do aminoácido triptofano, levando as células T à apoptose, devido à carência deste aminoácido e pela ação de seus catabólitos no micro ambiente placentário. Diversos tipos celulares estão presentes na interface materno fetal e vários deles podem potencialmente expressar a IDO. Em ratas Wistar, sabe-se que diversas proteínas, principalmente o interferon &gamma; e, recentemente, a progesterona, podem aumentar a expressão desta enzima; contudo, ainda não são conhecidos quais tipos celulares são efetivamente influenciados por estas moléculas. Desta forma, este trabalho buscou suprir esta lacuna, por meio da identificação das células IDO positivas pela imunofenotipagem e citometria de fluxo. De acordo com as analises realizadas, os resultados deste trabalho mostraram que todos os tipos celulares fenotipados foram capazes de expressar a enzima. Contudo somente alguns grupos específicos de células presentes no ambiente uterino placentário sofrem influência das proteínas supracitadas, principalmente as células dendríticas, e os linfócitos CD4 que elevam a expressão de IDO na presença de progesterona e IFN-&gamma;. Tais achados sugerem que a ação da enzima em grupos celulares específicos poderiam constituir meios pelo qual o organismo regula o sistema imunológico no ambiente uterino-placentário, em que é capaz de impedir o desenvolvimento de células imunológicas potencialmente ativas, colaborando com a formação de um ambiente tolerogênico favorável para o desenvolvimento embrionário. / Pregnancy causes several changes and challenges to the maternal body, especially involving the immune system. The fetus, on the immunological point of view, is compared to a semialogeneic graft, expressed as molecules of the paternal major histocompatibility complex (MHC) considered not self to the maternal organism, capable of triggering an immune response in the intrauterine environment. However, throughout the gestational period, maternal organism tolerates the embryo without an immune response against its permanence in the uterus, establishing maternal-fetal tolerance. Several mechanisms contribute to this tolerogenic state, as the activity of the enzyme indoleamine 2,3-dioxygenase (IDO). The IDO promotes the catabolism of tryptophan, inducing T cells apoptosis due to the deprivation of this amino acid and by the action of its catabolites in the placental microenvironment. Several cell types are present in the maternal-fetal interface and many of them can potentially express IDO. In Wistar rats, it is known that interferon &gamma; and recently, progesterone, may increase the expression of this enzyme; however, which cell types are actually influenced by these molecules is still unknown. Thus, this study intends to fill this gap, by identifying IDO positive cells by immunophenotyping and flow cytometry. According to the analysis carried out, the results of this study showed that all phenotyped cell types were able to express the enzyme, however only some specific groups present in placental uterine environment are influenced by the factors above mentioned, especially dendritic cells and lymphocytes CD4 increase the IDO expression at the presence of progesterone and IFN-&gamma;. These findings suggest that the action of the enzyme in specific cell groups may be one of the means by which the body regulates the immune system uterine-placental environment, which is able to prevent the development of potentially active immune cells, contributing to the formation tolerogenic environment favorable for embryonic development.