Associação entre perfil de citocinas e fatores de transcrição produzidos por subpopulações de células T na pré-eclâmpsia precoce e tardia
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Data
2017-02-22
Autores
Ribeiro, Vanessa Rocha [UNESP]
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Universidade Estadual Paulista (Unesp)
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Introdução: A pré-eclâmpsia (PE) é uma patologia obstétrica e uma das principais causas de morbimortalidade materna e fetal. Na PE ocorre um estado de má adaptação da tolerância imunológica, caracterizada por ativação anormal do sistema imune inato e adaptativo. As células T reguladoras (Treg) representam uma população de linfócitos T responsáveis pela manutenção da tolerância e controle da inflamação, enquanto células Th17 medeiam diferentes tipos de reações inflamatórias. Portanto, o balanço entre células Treg e Th17 pode ser crítico para a tolerância ao feto e prevenção da PE. Objetivo: Avaliar as subpopulações de células T CD4+ (Th1, Th2, Th17 e Treg) e o perfil de citocinas produzido por essas células, em gestantes portadoras de pré-eclâmpsia, classificadas em PE precoce e PE tardia. Métodos: Foram estudadas 60 gestantes, sendo 20 normotensas e 40 portadoras de PE, pareadas pela idade gestacional. As gestantes com PE foram classificadas de acordo com o aparecimento das manifestações clínicas em PE precoce (< 34 semanas de gestação; n=20) e PE tardia (≥ 34 semanas de gestação; n=20). Células mononucleares do sangue periférico (PBMCs), obtidas das gestantes foram avaliadas quanto à produção de citocinas pró e anti-inflamatórias e à expressão de fatores de transcrição envolvidos na caracterização das subpopulações de células T CD4+. A expressão dos fatores de transcrição intracitoplasmáticos de células Th1 (T-bet), Th2 (GATA-3), Th17 (RORc) e Treg (FoxP3) foi avaliada por citometria de fluxo e a expressão gênica desses fatores de transcrição foi determinada por PCR em tempo real com transcrição reversa (RT-qPCR), logo após a colheita de sangue para avaliação da expressão endógena dessas diferentes subpopulações de células T. A determinação das citocinas de perfil Th1 (IFN-γ e TNF-α), Th2 (IL-4), Th17 (IL-6, IL-17 e IL-22) e Treg (IL-10 e TGF-β1) foi realizada no plasma das gestantes pela técnica de ELISA. Os resultados foram analisados por meio de testes paramétricos ou não paramétricos com nível de significância de 5%. Resultados: Os perfis inflamatórios Th1 e Th17 foram identificados por aumento significativo da média de intensidade de fluorescência (MIF) e da percentagem de células expressando os fatores de transcrição específicos nas gestantes portadoras de PE precoce e PE tardia em relação aos grupos de gestantes normotensas com idade gestacional correspondente. A percentagem de células Th17 foi significativamente maior nas gestantes com PE precoce do que nas com PE tardia. Por outro lado, a análise dos perfis anti-inflamatórios Th2 e Treg mostrou que a percentagem de células expressando GATA-3 e FoxP3 foi significativamente menor nos grupos de PE precoce e PE tardia comparados aos grupos de normotensas, enquanto a comparação entre gestantes pré-eclâmpticas mostrou percentagem de células Treg significativamente menor nas gestantes portadoras de PE precoce. A expressão gênica do fator de transcrição T-bet por PBMCs não mostrou diferenças significativas entre os grupos de gestantes pré-eclâmpticas e de normotensas. Aumento significativo da expressão gênica do fator de transcrição RORc e diminuição da expressão dos genes GATA-3 e FoxP3 foram observados nos grupos de gestantes pré-eclâmpticas em relação aos grupos de normotensas de idade gestacional correspondente. Entre as gestantes pré-eclâmpticas, encontrou-se menor nível transcricional do fator de transcrição GATA-3 na PE precoce. Os níveis plasmáticos das citocinas IFN-γ, IL-6, IL-17 e TNF-α foram significativamente maiores nas gestantes portadoras de PE, enquanto as concentrações de IL-10 e TGF-β1 foram significativamente menores em comparação aos grupos de gestantes normotensas correspondentes. Observaram-se ainda, maiores níveis de IL-6, IL-17, TGF-β1 e TNF-α na PE precoce do que na PE tardia. A expressão proteica de IL-4 (perfil Th2) e IL-22 (perfil Th17), não apresentou diferença significativa entre os grupos estudados. Conclusão: Os resultados demonstram que o balanço entre células Treg e Th17 é deficiente na PE, havendo polarização para perfil Th17 na PE precoce. Esse desbalanço pode ser atribuído ao predomínio de citocinas pró-inflamatórias sobre as anti-inflamatórias, presentes na circulação de gestantes portadoras de pré-eclâmpsia.
Introduction: Preeclampsia (PE) is an obstetric pathology and one of the main causes of maternal and fetal morbidity and mortality. In PE there is a state of maladaptation of immunological tolerance, characterized by abnormal activation of the innate and adaptive immune system. Regulatory T cells (Treg) represent a population of T lymphocytes responsible for tolerance maintenance and inflammation control, whereas Th17 cells mediate different types of inflammatory reactions. Therefore, the balance between Treg and Th17 cells may be critical for fetal tolerance and PE prevention. Objective: To evaluate the subpopulations of CD4+ T cells (Th1, Th2, Th17 and Treg) and the cytokine profile produced by these cells in pregnant women with PE, classified in early-onset PE and late-onset PE. Methods: Sixty pregnant women, 20 normotensive and 40 preeclamptic women, matched by gestational age, were studied. Pregnant women with PE were classified according to clinical manifestations in early-onset PE (<34 weeks gestation; n = 20) and late-onset PE (≥ 34 weeks gestation; n = 20). Peripheral blood mononuclear cells (PBMCs) obtained from pregnant women were evaluated for the production of pro and anti-inflammatory cytokines and expression of transcription factors involved in the characterization of CD4+ T cell subpopulations. Expression of the intracytoplasmic transcription factors of Th1 (T-bet), Th2 (GATA-3), Th17 (RORc) and Treg (FoxP3) cells was assessed by flow cytometry and the gene expression of these transcription factors was determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) shortly after blood collection to evaluate the endogenous expression of these different T-cell subpopulations. The cytokine profile of Th1 cells (IFN-γ and TNF-α), Th2 (IL -4), Th17 (IL-6, IL-17 and IL-22) and Treg (IL-10 and TGF-β1) were measured in the plasma of the pregnant women by the ELISA. The results were analyzed using parametric or non-parametric tests with a significance level of 5%. Results: Th1 and Th17 inflammatory profiles were identified by a significant increase in mean fluorescence intensity (FMI) and by the percentage of cells expressing specific transcription factors in pregnant women with early-onset PE and late-onset PE in relation to the normotensive groups with corresponding gestational age. The percentage of Th17 cells was significantly higher in early-onset PE than in late-onset PE group. On the other hand, analysis of Th2 and Treg anti-inflammatory profiles showed percentages of cells expressing GATA-3 and FoxP3 significantly lower in the early- and late-onset PE groups compared to the normotensive groups, whereas the comparison between preeclamptic groups showed significantly lower percentage of Treg cells in pregnant women with early-onset PE. The gene expression of the T-bet transcription factor by PBMCs did not show significant differences between the preeclamptic and normotensive pregnant groups. Significant increase in the gene expression of RORc and decrease in the expression of the GATA-3 and FoxP3 genes were observed in both groups of preeclamptic women compared with the normotensive ones of corresponding gestational age. Among the preeclamptic pregnant women lower transcriptional level of GATA-3 transcription factor was detected in early-onset PE. Plasma levels of the cytokines IFN-γ, IL-6, IL-17 and TNF-α were significantly higher in pregnant women with PE, whereas IL-10 and TGF-β1 concentrations were significantly lower than in the normotensive corresponding groups. It was also observed higher levels of IL-6, IL-17, TGF-β1 and TNF-α in early-onset than in late-onset PE group. Protein expression of IL-4 (Th2 profile) and IL-22 (Th17 profile), did not show significant differences between the groups studied. Conclusion: The results show that the balance between Treg and Th17 cells is deficient in PE, with polarization to the Th17 profile in early-onset PE. This imbalance can be attributed to the predominance of pro-inflammatory cytokines over the anti-inflammatory ones present in the circulation of pregnant women with preeclampsia.
Introduction: Preeclampsia (PE) is an obstetric pathology and one of the main causes of maternal and fetal morbidity and mortality. In PE there is a state of maladaptation of immunological tolerance, characterized by abnormal activation of the innate and adaptive immune system. Regulatory T cells (Treg) represent a population of T lymphocytes responsible for tolerance maintenance and inflammation control, whereas Th17 cells mediate different types of inflammatory reactions. Therefore, the balance between Treg and Th17 cells may be critical for fetal tolerance and PE prevention. Objective: To evaluate the subpopulations of CD4+ T cells (Th1, Th2, Th17 and Treg) and the cytokine profile produced by these cells in pregnant women with PE, classified in early-onset PE and late-onset PE. Methods: Sixty pregnant women, 20 normotensive and 40 preeclamptic women, matched by gestational age, were studied. Pregnant women with PE were classified according to clinical manifestations in early-onset PE (<34 weeks gestation; n = 20) and late-onset PE (≥ 34 weeks gestation; n = 20). Peripheral blood mononuclear cells (PBMCs) obtained from pregnant women were evaluated for the production of pro and anti-inflammatory cytokines and expression of transcription factors involved in the characterization of CD4+ T cell subpopulations. Expression of the intracytoplasmic transcription factors of Th1 (T-bet), Th2 (GATA-3), Th17 (RORc) and Treg (FoxP3) cells was assessed by flow cytometry and the gene expression of these transcription factors was determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) shortly after blood collection to evaluate the endogenous expression of these different T-cell subpopulations. The cytokine profile of Th1 cells (IFN-γ and TNF-α), Th2 (IL -4), Th17 (IL-6, IL-17 and IL-22) and Treg (IL-10 and TGF-β1) were measured in the plasma of the pregnant women by the ELISA. The results were analyzed using parametric or non-parametric tests with a significance level of 5%. Results: Th1 and Th17 inflammatory profiles were identified by a significant increase in mean fluorescence intensity (FMI) and by the percentage of cells expressing specific transcription factors in pregnant women with early-onset PE and late-onset PE in relation to the normotensive groups with corresponding gestational age. The percentage of Th17 cells was significantly higher in early-onset PE than in late-onset PE group. On the other hand, analysis of Th2 and Treg anti-inflammatory profiles showed percentages of cells expressing GATA-3 and FoxP3 significantly lower in the early- and late-onset PE groups compared to the normotensive groups, whereas the comparison between preeclamptic groups showed significantly lower percentage of Treg cells in pregnant women with early-onset PE. The gene expression of the T-bet transcription factor by PBMCs did not show significant differences between the preeclamptic and normotensive pregnant groups. Significant increase in the gene expression of RORc and decrease in the expression of the GATA-3 and FoxP3 genes were observed in both groups of preeclamptic women compared with the normotensive ones of corresponding gestational age. Among the preeclamptic pregnant women lower transcriptional level of GATA-3 transcription factor was detected in early-onset PE. Plasma levels of the cytokines IFN-γ, IL-6, IL-17 and TNF-α were significantly higher in pregnant women with PE, whereas IL-10 and TGF-β1 concentrations were significantly lower than in the normotensive corresponding groups. It was also observed higher levels of IL-6, IL-17, TGF-β1 and TNF-α in early-onset than in late-onset PE group. Protein expression of IL-4 (Th2 profile) and IL-22 (Th17 profile), did not show significant differences between the groups studied. Conclusion: The results show that the balance between Treg and Th17 cells is deficient in PE, with polarization to the Th17 profile in early-onset PE. This imbalance can be attributed to the predominance of pro-inflammatory cytokines over the anti-inflammatory ones present in the circulation of pregnant women with preeclampsia.
Descrição
Palavras-chave
Citocinas, Fatores de transcrição, Pré-eclâmpsia precoce, Pré-eclâmpsia tardia, Subpopulações de células T., Cytokines, Early-onset preeclampsia, Late-onset preeclampsia, T cell subsets, Transcription factors