Profile of TNF-α receptors expressed in Th17 CD4+ lymphocytes in the peripheral blood of pregnant women with preeclampsia

Author(s)

Patrícia Braga da Silva

• Document type: Master's Dissertation
• Press: Botucatu. 2023-08-28.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina. Botucatu
• Defense date: 2023-07-18
• Advisor: Maria Terezinha Serrão Peraçoli; Mariana Romão Veiga

Abstract

Introduction: Pregnant women with pre-eclampsia (PE) have a shift in the immune response towards an inflammatory profile. The activation of peripheral blood monocytes, with exacerbated production of inflammatory cytokines such as tumor necrosis factor (TNF) and other inflammatory mediators, can cause activation of adaptive immunity cells, generating inflammatory CD4+ T cells. TNF can exert different functional effects on CD4+ T lymphocytes subpopulations through interaction with TNF receptors (TNFR1 and TNFR2). TNF binding to these two receptors activates different signaling pathways. TNFR1 induces cell death by apoptosis or necrosis and is also important for the development of inflammatory effector T cells, whereas TNFR2 is preferentially expressed by regulatory T cells (Treg). It is already known that in PE the T lymphocytes response is skewed towards the Th1 and Th17 inflammatory profile to the detriment of the regulatory profile, and this balance between Treg and Th17 cells may be critical for tolerance to the fetus and for disease prevention. Objectives: This project aimed to compare the expression of TNF receptors (TNFR1 and TNFR2) in peripheral blood CD4+ Th17 cells and their association with plasma levels of TNF and the soluble form of these receptors (sTNFR1 and sTNFR2) by pregnant women with PE and normotensive pregnant women (NT). Methods: 36 pregnant women were evaluated, 20 with PE and 16 with NT, matched by gestational age. The blood collected from these pregnant women was centrifuged, the plasma separated and stored at -80°C for measurement of TNF and soluble receptors sTNFR1 and sTNFR2 using the ELISA technique. The percentage of CD4+ Th17 cells was evaluated by the expression of the RORγt transcription factor, the expression of TNF receptors (TNFR1 and TNFR2) in this subpopulation and, the intracytoplasmic expression of TNF, IL-17A by flow cytometry. The results were analyzed using non-parametric tests with a significance level of 5%. Results: The expression of the TNFR1 receptor was increased in CD4+ T lymphocytes, as well as in Th17 profile lymphocytes, from pregnant women with PE when compared to NT pregnant women. In addition, the expression of the transcription factor RORγt and the intracytoplasmic cytokines TNF and IL-17A were also elevated in the PE group compared to the NT group. A positive correlation was observed between the expression of TNFR2 by CD4+ lymphocytes and the plasmatic concentration of sTNFR2 in preeclamptic pregnant women (r =0.5397; p=0.0171) while no correlation was observed between these markers in NT pregnant women. There was a positive correlation between plasma concentrations of sTNF and sTNFR1 in pregnant women with PE (r =0.5112; p=0.0257) and in normotensive pregnant women (r =0.5604; p=0.0365). The comparison between sTNFR1 and sTNFR2 showed a positive correlation both in pregnant women with PE (r =0.4500; p=0.349) and in NT pregnant women (r =0.5818; p=0.0302). Conclusion: The results confirm that pregnant women with PE have systemic inflammation, with CD4+ cells directed towards an inflammatory profile, due to the high expression of TNFR1 by Th17/RORγt+ lymphocytes and also by the increase of inflammatory cytokines, such as TNF and IL-17A, produced by these cells. The greater expression of TNFR1 in Th17 cells and the high concentration of this receptor in plasma suggest its role in the pathogenesis of PE. Future studies on the expression of anti-inflammatory markers in Treg/FoxP3+ cells may contribute to the understanding of the role of these cells in the Th17/Treg balance observed in PE. (AU)

• FAPESP's process: 21/12564-2 - Profile of TNF-alpha receptors expressed in Th17 CD4+ lymphocytes in the peripheral blood of pregnant women with preeclampsia
• Grantee: Patrícia Braga da Silva
• Support Opportunities: Scholarships in Brazil - Master