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An immunosuppressive treatment using tacrolimus improved pregnancy outcome of repeated implantation failure patients with elevated Th1/Th2 ratios.

Vitamin D has a pivotal role in regulating immune responses by promoting Th2 immune responses and suppressing Th1 responses. Propensities to a Th1 immune response and increased NK-cell levels and cytotoxicity have been reported in women with recurrent pregnancy losses (RPL). In women with RPL, vitamin D deficiency is prevalent IntroductionVitamin D is a group of secosteroids and has a major role in maintaining skeletal health. Various effects of vitamin D on extra skeletal tissues have been reported as well, during the past decade [1]. Vitamin D deficiency is endemic for both men and women and across different age groups in the US population [2]. Low C 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.eji-journal.eu Eur. J. Immunol. 2015. 45: 3188-3199 Clinical immunology 3189vitamin D level has been linked to major common health problems in populations, particularly inflammatory conditions such as cardiovascular disease, cancers, diabetes, autoimmune diseases including multiple sclerosis, rheumatoid arthritis, and others [3]. In addition, vitamin D deficiency is a predisposing factor for various female diseases such as osteoporosis, uterine fibroids, endometriosis, and breast cancer and a risk factor for obstetrical complications such as gestational diabetes and preeclampsia [4,5]. Recently, we have reported that 47.4% of women with recurrent pregnancy losses (RPL) have vitamin D deficiency [6]. In women with RPL, decreased vitamin D level was associated with the increased prevalence of antiphospholipid antibody, antinuclear antigen antibody, anti-ssDNA, and anti-thyroperoxidase antibody. In addition, peripheral blood CD19 + B and CD56 + NK-cell levels and NK cytotoxicity were significantly higher in women with low vitamin D level when compared with those of normal vitamin D level [6]. Normal pregnancy is associated with Th2 shift in T-cell immunity [7]. The comparable shift in NK-cell immunity has been reported during normal pregnancy including a bias to NKr1 that produce IL-10 in peripheral blood, and NK3 cells that produce TGF-β in decidual NK cells [8]. Additionally, decidual innate lymphoid cell 3 (ILC3) may play a role in innate defenses, and vessel and tissue rebuilding, thus contributing to maintenance of pregnancy [9]. Contrarily, a propensity to Th1 immune response and increased NK-cell levels and cytotoxicity have been reported in women with RPL and multiple implantation failures (MIF) after in vitro fertilization and embryo transfer cycles [10]. Women with miscarriages and preeclampsia as well, have NK1 and NKT1 shift that produce high amounts of IFN-γ and little IL-4 in peripheral blood [11]. Therefore, cellular immune-regulation including innate immunity is critical for human reproduction.Women with RPL and MIF have significantly higher NK-cell levels and cytotoxicity, and dysregulated cytokine production patterns as compared to normal controls [10,12]. Activating receptor expression on NK cells was significantly increased, while inhibitory receptor expression was significantly decreased in ...

In young adults, bone lost through osteoclast-mediated resorption is precisely replaced in both location and amount. Understanding how these two processes are coupled is crucial to advancing treatments for osteoporosis, a disease that progresses when the processes become uncoupled. We documented that osteoclasts secrete the mammalian integration 1 gene that is the homolog of Drosophila Wngless (Wnt) 10b, bone morphogenetic protein 6 (BMP6), and the chemokine sphingosin 1 phosphate (S1P) to promote mesenchymal cell mineralization in vitro. During bone resorption, TGF-β1 is released from the bone extracellular matrix and activated by osteoclasts. Thus, TGF-β1 levels are elevated during the resorption phase of bone turnover. We therefore investigated the influences of TGF-β1 on osteoclast-mediated support of mineralization. TGF-β1 increased osteoclast production of Wnt10b, but not BMP6 or S1P. Blocking Wnt10b activity with the Wnt signaling inhibitor Dickkoph-related protein 1 suppressed the ability of TGF-β-treated osteoclast-conditioned media to promote osteoblast mineralization. Examination of TGF-β signaling in osteoclasts revealed that induction of Wnt10b expression was dependent on Smad2/3 activation and independent from TGF-β1 stimulation of protein kinase B (AKT) or MAPK kinase. TGF-β1-treated osteoclast-conditioned media from cells with blocked Smad signaling exhibited a reduced ability to support mineralization, demonstrating the importance of Smad signaling in this response. Parallel cultures with suppressed TGF-β activation of AKT or MAPK kinase signaling retained their ability to elevate mineralization. These results demonstrate that TGF-β1 stimulates Wnt10b production in osteoclasts, which may enhance restoration of the bone lost during the resorptive phase of bone turnover.

The processes of bone resorption and bone formation are tightly coupled in young adults, which is crucial to maintenance of bone integrity. We have documented that osteoclasts secrete chemotactic agents to recruit osteoblast lineage cells, contributing to coupling. Bone formation subsequent to bone resorption becomes uncoupled with aging, resulting in significant bone loss. During bone resorption, osteoclasts release and activate transforming growth factor beta 1 (TGF-β1) from the bone matrix; thus, elevated bone resorption increases the level of active TGF-β in the local environment during aging. In this study, we examined the influences of TGF-β1 on the ability of osteoclasts to recruit osteoblasts. TGF-β1 increased osteoclast expression of the chemokine CXCL16 to promote osteoblast migration. TGF-β1 also directly stimulated osteoblast migration, however, this direct response was blocked by conditioned medium from TGF-β1-treated osteoclasts due to the presence of leukemia inhibitory factor (LIF) in the medium. CXCL16 and LIF expression was dependent on TGF-β1 activation of Smad2 and Smad3. These results establish that TGF-β1 induces CXCL16 and LIF production in osteoclasts, which modulate recruitment of osteoblasts to restore the bone lost during the resorptive phase of bone turnover.