Innate Immune Responses of Trophoblasts in Pregnancy

描述（由申请人提供）：这些研究是本实验室先前资助的RO1实验的延续。由于没有良好的生物标志物或预防策略，感染相关的妊娠并发症是一个重要的临床问题。toll样受体（TLR）在母胎界面的表达和功能调控可能决定妊娠的成功或失败。通过了解控制滋养细胞TLRs功能的机制，我们才能转向临床应用，以确定更好的方法来预测妊娠结局，并治疗有感染相关妊娠并发症风险的妇女。胎盘过度凋亡与子痫前期和早产有关；然而，最初的触发因素和相关机制尚不完全清楚。我们认为感染是胎盘凋亡的潜在触发因素，一些tlr可以介导这种反应。具体来说，我们的中心假设是一些细菌和病毒成分通过tlr诱导滋养细胞凋亡，导致不良妊娠结局，如早产或先兆子痫。在我们发表的研究中，我们发现革兰氏阳性细菌肽聚糖（PDG）激活TLR2，病毒ssRNA激活TLR8，通过两种不同的途径触发人妊娠早期滋养细胞凋亡：TLR2直接介导细胞凋亡，并受TLR2共受体TLR6的差异调节。相反，TLR8通过上调细胞中IFN2的产生间接介导细胞凋亡。我们的目标是进一步表征TLR2和TLR8在细菌和病毒成分作用下介导滋养细胞凋亡的细胞和分子机制，并确定它们对妊娠结局的影响。在这一总体目标中，我们将解决我们知识中存在重大空白的创新领域，例如：通过DNA甲基化调节TLR表达；TLRs对滋养细胞miRs的调控；TLR8在滋养细胞中的作用；以及病毒ssRNA对妊娠结局的影响。我们还将把我们的体外研究结果应用到研究中，以制定更好的预测和预防策略。因此，我们的具体目标是：确定tlr2对细菌成分诱导的细胞凋亡的调控作用。2. 确定TLR8在滋养细胞中响应病毒成分的作用机制。3. 确定microrna在TLR2-和tlr8介导的滋养细胞凋亡调控中的作用。4. 评估tlr在妊娠中的作用。虽然细菌感染和妊娠并发症之间的联系已经确立，但人们对病毒感染如何影响妊娠知之甚少。尽管最近我们对胎盘tlr在妊娠中的作用的了解有所增加，但我们对其具体机制的了解仍然有限，tlr在介导细胞凋亡中的作用也是如此。我们的发现将进一步加深我们对正常胎盘功能的理解，并将导致更好的理解，预测和治疗感染相关的妊娠并发症。

DESCRIPTION (provided by applicant): These studies are a continuation of experiments originated in our laboratory, from a previously funded RO1. Since there are no good biomarkers or preventative strategies, infection-associated pregnancy complications represent an important clinical problem. The regulation of Toll-like receptor (TLR) expression and function at the maternal-fetal interface may determine whether a pregnancy succeeds or fails. By understanding the mechanisms that control how trophoblast TLRs function, only then can we move to clinical applications to determine better ways to predict pregnancy outcome and treat women at risk of infection-associated pregnancy complications. Excessive placental apoptosis has been associated with preeclampsia and preterm labor; however the initial trigger and mechanisms involved are not fully understood. We propose that infections represent a potential trigger for placental apoptosis, and that some TLRs can mediate this response. Specifically, our central hypothesis is that some bacterial and viral components, through TLRs, induce trophoblast apoptosis, leading to adverse pregnancy outcome, such as preterm labor or preeclampsia. In our published studies we found TLR2 activation by gram-positive bacterial peptidoglycan (PDG), and TLR8 activation by viral ssRNA, trigger human first trimester trophoblast apoptosis via two distinct pathways: TLR2 directly mediates apoptosis, and this is differentially regulated by the TLR2 co-receptor, TLR6. In contrast, TLR8 indirectly mediates apoptosis by upregulating the cell's production of IFN2. Our objectives are to further characterize the cellular and molecular mechanisms by which TLR2 and TLR8 mediate trophoblast apoptosis in response to bacterial and viral components, and to determine their impact on pregnancy outcome. Within this overall goal, we will address innovative areas in which there are major gaps in our knowledge, such as the: regulation of TLR expression by DNA methylation; regulation of trophoblast miRs by TLRs; function of TLR8 in the trophoblast; and the effect of viral ssRNA on pregnancy outcome. We will also apply translate our in vitro findings into a study to develop better predictive and preventative strategies. Thus, our specific aims are to: 1. Determine the regulation of TLR2-induced apoptosis in response to bacterial components. 2. Determine the mechanism by which TLR8 functions in the trophoblast in response to viral components. 3. Determine the role of microRNAs in the regulation of TLR2- and TLR8-mediated trophoblast apoptosis. 4. Evaluate the role of TLRs in pregnancy. While the link between bacterial infections and pregnancy complications is well established, less is known about how viral infections affect pregnancy. Despite a recent increase in our understanding of the role of placental TLRs in pregnancy, our knowledge about the specific mechanisms involved is still limited, as is the role of TLRs in mediating apoptosis. Our findings will further our understanding of normal placental function, and will lead to a better understanding, prediction and treatment of infection-associated pregnancy complications.