Cord blood soluble Fas ligand linked to allergic rhinitis and lung function in seven-year-old children

Background Serum or cord blood soluble Fas ligand (FasL) has been related to asthma, allergic rhinitis, and atopic dermatitis in cross-sectional and short-term follow-up studies. However, the association of cord blood soluble FasL with long-term allergic outcomes has seldom been investigated. Thus, this study investigated the relationship between cord blood soluble FasL and long-term allergic outcomes in a follow-up birth cohort. Methods The Prediction of Allergies in Taiwanese Children birth cohort study recruited healthy newborns upon delivery. At birth, blood was collected from the umbilical cords of these children, and the cord blood soluble Fas ligand levels were measured. At the age of seven years, the allergic outcome of each child was diagnosed by pediatric allergists and pulmonologists. Tests were conducted to measure the specific immunoglobulin E, fractional exhaled nitric oxide (FeNO), and pulmonary function levels of each child. Results Cord blood soluble FasL levels were higher in 7-year-old children with allergic rhinitis (Odds ratio [OR] = 2.41, p = .012) and expiratory airway obstruction (the highest forced expiratory volume in 1 second/ forced vital capacity < 90%, OR = 2.11, p = .022). The FeNO and Dermatophagoides pteronyssinus-specific immunoglobulin E levels of 7-year-old children were positively correlated with cord blood soluble FasL levels (p = .006 and .02, respectively). Conclusions In this birth cohort, the cord blood soluble FasL levels were associated with allergic rhinitis, obstructive-type lung function, FeNO, and house dust mite sensitization in 7-year-old children. The cord blood soluble FasL level might be used as a predictor for allergic diseases in children who are 7 years old.

Nanoscale Organization of FasL on DNA Origami as a Versatile Platform to Tune Apoptosis Signaling in Cells

Nanoscale probes with fine-tunable properties are of key interest in cell biology and nanomedicine to elucidate and eventually control signaling processes in cells. A critical, still challenging issue is to conjugate these probes with molecules in a number- and spatially-controlled manner. Here, DNA origami-based nanoagents as nanometer precise scaffolds presenting Fas ligand (FasL) in well-defined arrangements to cells are reported. These nanoagents activate receptor molecules in the plasma membrane initiating apoptosis signaling in cells. Signaling for apoptosis depends sensitively on FasL geometry: fastest time-to-death kinetics are obtained for FasL nanoagents representing predicted structure models of hexagonal receptor ordering with 10 nm inter-molecular spacing. Slower kinetics are observed for one to two FasL on DNA origami or FasL coupled with higher flexibility. Nanoagents with FasL arranged in hexagons with small (5 nm) and large (30 nm) spacing impede signal transduction. Moreover, for predicted hexagonal FasL nanoagents, signaling efficiency is faster and 100× higher compared to naturally occurring soluble FasL. Incubation of the FasL-origami nanoagent in solution exhibited an EC50 value of only 90 pM. These studies present DNA origami as versatile signaling platforms to probe the significance of molecular number and nanoscale ordering for signal initiation in cells.

Evaluation of efficiency of Fas-mediated apotosis of peripheral blood lymphocytes in patients with type 1 diabetes mellitus

The Fas/FasL system is known to play a central role in maintaining peripheral self-tolerance and tissue homeostasis of the organism [12, 18]. Fas-mediated apoptosis is induced by binding of the Fas(CD 95/APO-l/TNFRSF6)-receptor to the Fas(CD 95L/CD 178/TNFSF6)-ligand on the respective cells [24]. Triggering of the expression of cell surface Fas receptors (Fas) regulates the elimination of autoreactive T- and B-lymphocytes by apoptosis. It is known that impaired activation of Fas-mediated apoptosis in individual subpopulations of T-cells plays an important role in the pathogenesis of type 1 diabetes mellitus (T1DM). The main key point in the development of T1DM is resistance to apoptosis of activated autoreactive T-lymphocytes, which migrate from the bloodstream to the pancreas and take an active part in β-cells destruction. Аt the present time, most of the results on the study of Fas-mediated apoptosis in T1DM were obtained in experiments in vitro [11, 18, 31]. There is no doubt that in vivo autoimmune pathological changes are more profound, and extrapolation of the results obtained in the experiment to the organism is not always valid. Тhereby, it seems relevant to evaluate the efficiency of Fas-mediated apoptosis of T-lymphocytes in the blood of patients with T1DM, depending on the compensation phase and the duration of the disease. In the article, the markers of Fas-mediated apoptosis of peripheral blood lymphocytes in patients with type 1 diabetes mellitus and individuals with high risk of T1DM development have been studied. The surface expression of Fas in individual subpopulations of T-lymphocytes was еvaluated. The inhibition of Fas-mediated apoptosis of autoreactive CD 95+-cells by soluble Fas-receptor was detected in patients with decompensation of T1DM. In compensation phase of T1DM Fas-mediated apoptosis of lymphocyte was successfully realized via the soluble Fas ligand (sFasL). The increased level of soluble FasL was revealed in compensation phase of T1DM and in individuals with high risk of T1DM development. This probably has a protective value, since the soluble FasL is involved in the removal of the peripheral blood autoreactive CD 95+-cells.

Soluble FAS ligand is not required for pancreatic islet inflammation or beta-cell destruction in non-obese diabetic mice

CD8+ T cells play a central role in beta-cell destruction in type 1 diabetes. CD8+ T cells use two main effector pathways to kill target cells, perforin plus granzymes and FAS ligand (FASL). We and others have established that in non-obese diabetic (NOD) mice, perforin is the dominant effector molecule by which autoreactive CD8+ T cells kill beta cells. However, blocking FASL pharmacologically was shown to protect NOD mice from diabetes, indicating that FASL may have some role. FASL can engage with its receptor FAS on target cells either as membrane bound or soluble FASL. It has been shown that membrane-bound FASL is required to stimulate FAS-induced apoptosis in target cells, whereas excessive soluble FASL can induce NF-κB-dependent gene expression and inflammation. Because islet inflammation is a feature of autoimmune diabetes, we tested whether soluble FASL could be important in disease pathogenesis independent of its cell death function. We generated NOD mice deficient in soluble FASL, while maintaining expression of membrane-bound FASL due to a mutation in the FASL sequence required for cleavage by metalloproteinase. NOD mice lacking soluble FASL had normal numbers of lymphocytes in their spleen and thymus. Soluble FASL deficient NOD mice had similar islet inflammation as wild-type NOD mice and were not protected from diabetes. Our data indicate that soluble FASL is not required in development of autoimmune diabetes.

Serum Levels Of CD178 (Soluble FasL) Predict Treatment Response and Survival In Chronic Lymphocytic Leukaemia (CLL)

Background CLL cells have prolonged survival in vivo, but rapidly undergo apoptosis when cultured ex vivo indicating the importance of the tumour microenvironment in resistance to apoptosis. Chemokines and their receptors have been identified as playing a critical role in the CLL microenvironment and we have previously identified CCL2, CXCL2, IL-6 and IL-8 as pro-survival factors in our in vitro long-term CLL culture model. We examined the in vivo significance of these and other chemokines by examining serum levels in a cohort of uniformly treated patients with CLL. Methods Serum samples were collected from 32 Australian patients participating in the German CLL Study Group CLL8 trial prior to treatment and were assessed for circulation levels of several cytokines and chemokines. Serum samples from 7 age matched healthy donors were used as controls. Serum concentration of CCL21, CXCL12, CXCL13, CCL19 and CXCL2 were examined using enzyme-linked immunosorbent assays (ELISA) and levels of CCL2, CCL3, CCL4, sCD54, sCD178, IL6 and IL-8 were examined using flex sets of BD Cytometric Bead Arrays System. Levels of these cytokines and chemokines were compared both to the healthy donor control samples and correlated with known prognostic and clinical factors. The levels were also evaluated in respect to response to therapy, progression-free survival (PFS) and overall survival (OS). Results 32 patients were studied: median age 62yrs, 84% male, Binet stage B 63%, stage C 37%. 15 received FCR and 17 FC with a median PFS of 45 months and median OS not reached. Compared to controls, patients with CLL had significantly higher serum levels of CXCL13 (117pg/ml vs 15pg/ml, p=0.0001), CCL3 (273pg/ml vs 103pg/ml, p=0.0007), CCL4 (13pg/ml vs 0pg/ml, p=0.0057), CD178 (45pg/ml vs 26pg/ml, p=0.01) and IL-6 (5pg/ml vs 0, p=0.02) and significantly lower levels of CXCL12 (803pg/ml vs 1177pg/ml, p=0.003) and sCD154 (345pg/ml vs 2121pg/ml p=0.0004). CCL2 levels did not correlate with any baseline clinical feature, response to therapy, PFS or OS. CXCL2 levels reduced with more advanced Rai stage disease (p=0.0083) but did not predict PFS or OS. CD178 levels did not correlate with any baseline clinical feature but predicted response to therapy with lower levels predicting improved response (p=0.04). Higher CD178 also strongly predicted worse PFS (HR 1.026, p<0.001) and OS (HR 1.02, p=0.018), a consistent effect whether treated with FC (HR 1.023, p=0.024) or FCR (HR 1.026, p=0.026). No other chemokine levels predicted PFS. Conclusion Baseline serum levels of CD178 (soluble FasL) may be a useful predictor of response to therapy and outcome in CLL. Further studies to confirm these findings and to define the biological mechanism of FasL overexpression and function are required. Acknowledgments We thank the German CLL Study Group and Roche for access to patient samples and data from the CLL8 study, and the Leukaemia Foundation of Australia for grant support. Disclosures: Mollee: Roche Australia: Sponsorship for attending ICML Lugano 2013 Other.