Uterine NK cells are critical in shaping DC immunogenic functions compatible with pregnancy progression.

Dendritic cell (DC) and natural killer (NK) cell interactions are important for the regulation of innate and adaptive immunity, but their relevance during early pregnancy remains elusive. Using two different strategies to manipulate the frequency of NK cells and DC during gestation, we investigated their relative impact on the decidualization process and on angiogenic responses that characterize murine implantation. Manipulation of the frequency of NK cells, DC or both lead to a defective decidual response characterized by decreased proliferation and differentiation of stromal cells. Whereas no detrimental effects were evident upon expansion of DC, NK cell ablation in such expanded DC mice severely compromised decidual development and led to early pregnancy loss. Pregnancy failure in these mice was associated with an unbalanced production of anti-angiogenic signals and most notably, with increased expression of genes related to inflammation and immunogenic activation of DC. Thus, NK cells appear to play an important role counteracting potential anomalies raised by DC expansion and overactivity in the decidua, becoming critical for normal pregnancy progression

CXCR4+ Dendritic cells promote angiogenesis during embryo implantation in mice

Early pregnancy is characterized by decidual adaption to the developing embryo involving angiogenesis and vascular growth. Failure of decidual vascular expansion is linked to diseases of pregnancy. Dendritic cells (DC) have been associated with vascular growth during early gestation, though it is unknown whether their capacity to modulate angiogenesis is ubiquitous to all DC subsets. Here, we show that DC normally found associated with the decidual vasculature co-express the C–X–C chemokine receptor type 4 (CXCR4). In addition, we demonstrate that impaired homing of CXCR4+DC during early gestation provoked a disorganized decidual vasculature with impaired spiral artery remodeling later in gestation. In contrast, adoptive transfer experiments provided evidence that CXCR4+DC are able to rescue early pregnancy by normalizing decidual vascular growth and delivery of pro-angiogenic factors, which results in adequate remodeling of the spiral arteries during placental development. Taken together, our results indicate an important role of CXCR4+DC in the regulation of decidual angiogenesis and highlight the importance of the CXCL12/CXCR4 pathway during this process, suggesting that this may represent a key pathway to evaluate during pregnancy pathologies associated with impaired vascular expansion.Fil: Barrientos, Gabriela Laura. Charité Universitätsmedizin Berlin; AlemaniaFil: Tirado González, Irene. Charité Universitätsmedizin Berlin; AlemaniaFil: Freitag, Nancy. Charité Universitätsmedizin Berlin; AlemaniaFil: Kobelt, Peter. Charité Universitätsmedizin Berlin; AlemaniaFil: Moschansky, Petra. Charité Universitätsmedizin Berlin; AlemaniaFil: Klapp, Burghard F.. Charité Universitätsmedizin Berlin; AlemaniaFil: Thijssen, Victor L.J.L.. Vrije Universiteit; Países BajosFil: Blois, Sandra M.. Charité Universitätsmedizin Berlin; Alemani

In vivo dendritic cell depletion reduces breeding efficiency, affecting implantation and early placental development in mice

Implantation of mammalian embryos into their mother's uterus ensures optimal nourishment and protection throughout development. Complex molecular interactions characterize the implantation process, and an optimal synchronization of the components of this embryo-maternal dialogue is crucial for a successful reproductive outcome. In the present study, we investigated the role of dendritic cells (DC) during implantation process using a transgenic mouse system (DTRtg) that allows transient depletion of CD11c+ cells in vivo through administration of diphtheria toxin. We observed that DC depletion impairs the implantation process, resulting in a reduced breeding efficiency. Furthermore, the maturity of uterine natural killer cells at dendritic cell knockout (DCKO) implantation sites was affected as well; as demonstrated by decreased perforin expression and reduced numbers of periodic-acid-Schiff (PAS)-positive cells. This was accompanied by disarrangements in decidual vascular development. In the present study, we were also able to identify a novel DC-dependent protein, phosphatidylinositol transfer protein β (PITPβ), involved in implantation and trophoblast development using a proteomic approach. Indeed, DCKO mice exhibited substantial anomalies in placental development, including hypocellularity of the spongiotrophoblast and labyrinthine layers and reduced numbers of trophoblast giant cells. Giant cells also down-regulated their expression of two characteristic markers of trophoblast differentiation, placental lactogen 1 and proliferin. In view of these findings, dendritic cells emerge as possible modulators in the orchestration of events leading to the establishment and maintenance of pregnancy. © 2008 Springer-Verlag

Balanced levels of nerve growth factor are required for normal pregnancy progression

Nerve growth factor (NGF), the first identified member of the family of neurotrophins, is thought to play a critical role in the initiation of the decidual response in stress-challenged pregnant mice. However, the contribution of this pathway to physiological events during the establishment and maintenance of pregnancy remains largely elusive. Using NGF depletion and supplementation strategies alternatively, in this study, we demonstrated that a successful pregnancy is sensitive to disturbances in NGF levels in mice. Treatment with NGF further boosted fetal loss rates in the high-abortion rate CBA/J x DBA/2J mouse model by amplifying a local inflammatory response through recruitment of NGF-expressing immune cells, increased decidual innervation with substance P(+) nerve fibres and a Th1 cytokine shift. Similarly, treatment with a NGF-neutralising antibody in BALB/c-mated CBA/J mice, a normal-pregnancy model, also induced abortions associated with increased infiltration of tropomyosin kinase receptor A-expressing NK cells to the decidua. Importantly, in neither of the models, pregnancy loss was associated with defective ovarian function, angiogenesis or placental development. We further demonstrated that spontaneous abortion in humans is associated with up-regulated synthesis and an aberrant distribution of NGF in placental tissue. Thus, a local threshold of NGF expression seems to be necessary to ensure maternal tolerance in healthy pregnancies, but when surpassed may result in fetal rejection due to exacerbated inflammation

Profiling Lgals9 splice variant expression at the fetal-maternal interface: implications in normal and pathological human pregnancy

Disruption of fetal-maternal tolerance mechanisms can contribute to pregnancy complications, including spontaneous abortion. Galectin-9 (LGALS9), a tandem repeat lectin associated with immune modulation, is expressed in the endometrium during the mid and late secretory phases and in decidua during human early pregnancy. However, the role of LGALS9 during pregnancy remains poorly understood. We used real-time PCR and immunohistochemical staining to analyze the expression of Lgals9/LGALS9 during mouse gestation as well as in human tissues obtained from normal pregnancy and spontaneous abortions. In mice, three Lgals9 splice variants were detected, the expression of which was differentially regulated during gestation. Furthermore, decidual Lgals9 expression was deregulated in a mouse model of spontaneous abortion, whereas placental levels did not change. We further found that the LGALS9 D5 isoform suppresses interferon gamma production by decidual natural killer cells. In human patients, six Lgals9 splice variants were detected, and a decrease in Lgals9 D5/10 was associated with spontaneous abortion. Altogether, these results show a differential regulation of Lgals9 isoform expression during normal and pathological pregnancies and designate Lgals9 as a potential marker for adverse pregnancy outcomes.Fil: Heusschen, Roy. VU University Medical Center; Países BajosFil: Freitag, Nancy. Medicine University of Berlin; AlemaniaFil: Tirado González, Irene. Medicine University of Berlin; AlemaniaFil: Barrientos, Gabriela Laura. Medicine University of Berlin; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Moschansky, Petra. Medicine University of Berlin; AlemaniaFil: Muñoz Fernández, Raquel. Consejo Superior de Investigaciones Cientificas; EspañaFil: Leno Durán, Ester. Universidad de Granada; EspañaFil: Klapp, Burghard F.. Medicine University of Berlin; AlemaniaFil: Thijssen, Victor L.J.L.. VU University Medical Center; Países BajosFil: Blois, Sandra M.. Medicine University of Berlin; Alemani

Dendritic cells regulate angiogenesis associated with liver fibrogenesis

During liver fibrogenesis the immune response and angiogenesis process are fine-tuned resulting in activation of hepatic stellate cells that produce an excess of extracellular matrix proteins. Dendritic cells (DC) play a central role modulating the liver immunity and have recently been implicated to favour fibrosis regression; although their ability to influence the development of fibrogenesis is unknown. Therefore, we explored whether the depletion of DC during early stages of liver injury has an impact in the development of fibrogenesis. Using the CD11c.DTR transgenic mice, DC were depleted in two experimental models of fibrosis in vivo. The effect of anti-angiogenic therapy was tested during early stages of liver fibrogenesis. DC depletion accelerates the development of fibrosis and as a consequence, the angiogenesis process is boosted. We observed up-regulation of pro-angiogenic factors together with an enhanced vascular endothelial growth factor (VEGF) bioavailability, mainly evidenced by the decrease of anti-angiogenic VEGF receptor 1 (also known as sFlt-1) levels. Interestingly, fibrogenesis process enhanced the expression of Flt-1 on hepatic DC and administration of sFlt-1 was sufficient to abrogate the acceleration of fibrogenesis upon DC depletion. Thus, DC emerge as novel players during the development of liver fibrosis regulating the angiogenesis process and thereby influencing fibrogenesis.Fil: Blois, Sandra M.. Universitätsmedizin de Berlín; AlemaniaFil: Piccioni, Flavia Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ciencias Biomédicas. Laboratorio de Investigaciones Biomédicas; ArgentinaFil: Freitag, Nancy. Universitätsmedizin de Berlín; AlemaniaFil: Tirado González, Irene. Universitätsmedizin de Berlín; AlemaniaFil: Moschansky, Petra. Universitätsmedizin de Berlín; AlemaniaFil: Lloyd, Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ciencias Biomédicas. Laboratorio de Investigaciones Biomédicas; ArgentinaFil: Hensel Wiegel, Karin. Universitätsmedizin de Berlín; AlemaniaFil: Rose, Matthias. Universitätsmedizin de Berlín; AlemaniaFil: García, Mariana Gabriela. Universidad Austral. Facultad de Ciencias Biomédicas. Laboratorio de Investigaciones Biomédicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alaniz, Laura Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ciencias Biomédicas. Laboratorio de Investigaciones Biomédicas; ArgentinaFil: Mazzolini Rizzo, Guillermo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ciencias Biomédicas. Laboratorio de Terapia Genética; Argentin

Murine abortion is associated with enhanced Hyaluronan expression and abnormal localization at the fetomaternal interface

The remodelling of the endometrial architecture is fundamental to create a suitable environment for the establishment of pregnancy. During this process, substantial alterations in the composition of maternal extracellular matrix play an important role by providing a prosperous medium for implantation as well as modulating trophoblast invasion leading to the formation of a functional placental unit. Hyaluronan is a conspicuous component of the extracellular matrix, particularly in remodelling tissues undergoing regeneration and repair. During gestation, changes in HA deposition and distribution indicate that this molecule may participate in preparation of the endometrial stroma for reception and implantation of the embryo. However, little is known about the role of hyaluronan at the fetomaternal interface, specially regarding its influence in pregnancy outcome. In the present study we show increased decidual hyaluronan levels in spontaneous abortion compared with normal pregnancy mice on gestation day 7.5. Both in normal and pathologic pregnancies, high molecular size hyaluronan was found at the fetomaternal unit. However, hyaluronan metabolism (which results from the activity of hyaluronan synthases and hyaluronidases) seems to be altered in spontaneous abortion as shown by a decrease in Hyal-3 expression as well as by differences in hyaluronan molecular size spectrum. This alteration in hyaluronan metabolism in spontaneous abortion could explain its increased concentration observed in decidua and the abnormal distribution of hyaluronan around the embryo implantation crypt. Thus, increased decidual hyaluronan levels resulting from abnormal deposition and turn over may contribute to the pathogenesis of pregnancy failure.Fil: Cordo Russo, Rosalia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentina. Universität zu Berlin; AlemaniaFil: García, Mariana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentina. Universität zu Berlin; AlemaniaFil: Barrientos, Gabriela Laura. Universität zu Berlin; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Orsal, A. S.. Universität zu Berlin; AlemaniaFil: Viola, M.. Universita degli Studi dell’Insubria; ItaliaFil: Moschansky, Petra. Universität zu Berlin; AlemaniaFil: Ringel, F.. Universität zu Berlin; AlemaniaFil: Passi, A.. Universita degli Studi dell’Insubria; ItaliaFil: Alaniz, Laura Daniela. Universidad Austral. Facultad de Ciencias Biomédicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Hajos, Silvia Elvira. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Blois, Sandra M.. Universität zu Berlin; Alemani