Assessment of Placental Extracellular Vesicles-Associated Fas Ligand and TNF-Related Apoptosis-Inducing Ligand in Pregnancies Complicated by Early and Late Onset Preeclampsia

Preeclampsia (PE) is a hypertensive disorder that affects 2–8% of pregnancies and is one of the main causes of fetal, neonatal, and maternal mortality and morbidity worldwide. Although PE etiology and pathophysiology remain unknown, there is evidence that the hyperactivation of maternal immunity cells against placental cells triggers trophoblast cell apoptosis and death. It has also been reported that placenta-derived extracellular vesicles (EV) carry Fas ligand (FasL) and Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and trigger apoptosis in Jurkat T cells. This study aimed to quantify and compare FasL and TRAIL expression in EV derived from cultures of placenta explants from women with PE (early versus late) and women with uncomplicated pregnancies. Also, the study assessed EV capacity to induce apoptosis in Jurkat T cells. The authors isolated EV from placenta explant cultures, quantified FasL and TRAIL using ELISA, and analyzed EV apoptosis-inducing capability by flow cytometry. Results showed increased FasL and TRAIL in EV derived from placenta of women with PE, and increased EV apoptosis-inducing capability in Jurkat T cells. These results offer supporting evidence that EV FasL and TRAIL play a role in the pathophysiology of PE.

Metformin-induced TRAIL Upregulation Promotes Apoptosis in Triple Negative Breast Cancer and Non-small Cell Lung Cancer Cells

Background: Triple negative breast cancer (TNBC) and non-small cell lung cancer (NSCLC) are highly aggressive types of cancer with limited therapeutic options. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) shows promising antitumor activity and is well tolerated in preclinical studies. However, the efficacy of recombinant TRAIL in clinical trials is compromised in part by its short serum half-life and low in vivo stability. Induction of endogenous TRAIL may overcome the limitations and become a new strategy for cancer treatment. Methods: Cell proliferation (MTS) and colony formation assays were performed to determine the anti-proliferative/anti-survival effects of metformin, a common drug for type II diabetes, on TNBC and NSCLC cells. A Live/Dead imaging assay and specific apoptotic ELISA analyzed cells undergoing apoptosis. Western blot analyses were used to examine protein expression and cleavage. A recombinant TRAIL-R2-Fc chimera protein was applied to block TRAIL binding to its receptors. Lentiviral vector containing shRNAs was used to specifically knockdown TRAIL expression. A tumor xenograft model was established by inoculation of H460 cells into nude mice. The tumor-bearing mice were treated with metformin to assess the drug’s antitumor activity. Immunohistochemistry was carried out to study the effects of metformin on tumor cell proliferation and induction of apoptosis and TRAIL in vivo. Results: Metformin upregulated TRAIL protein, but not mRNA expression, which correlated with increased apoptosis in TNBC and NSCLC cells. Metformin did not alter the expression of TRAIL receptors (TRAIL-R1/DR4 and TRAIL-R2/DR5). Metformin-induced TRAIL was secreted into conditioned medium (CM) and functional, since the CM potently promoted apoptosis in MDA-MB-231 cells, which was effectively blocked by a recombinant TRAIL-R2-Fc chimera protein. Inhibition of TRAIL function by blockade of its binding to DR4/DR5 or specific knockdown of TRAIL expression significantly attenuated metformin-induced apoptosis. Studies with a tumor xenograft model revealed that metformin not only significantly inhibited tumor growth; it also elicited apoptosis and upregulated TRAIL expression in vivo. Conclusions: TRAIL upregulation and activation of death receptor signaling are pivotal for metformin-induced apoptosis in TNBC and NSCLC cells. Our studies identify a novel mechanism of action of metformin exhibiting potent antitumor activity via induction of endogenous TRAIL.

Cell Density of NK Cells during Ex Vivo Expansion Impacts NK Cell Surface TRAIL Expression

Introduction Natural Killer (NK) cells are an emerging form of cancer immunotherapy currently being tested in clinical trials world-wide. NK cells are innate immune cells that can kill tumor cells via release of cytotoxic granules and via surface expression of the death receptor ligands tumor-related apoptosis-inducing ligand (TRAIL) and Fas ligand. We and others have recently shown that the proteasome inhibitor bortezomib sensitizes tumor cells to NK cell TRAIL-mediated killing by upregulation of death receptor 5. In a recent phase I NK cell dose-escalation study conducted at the NIH (NCT00720785) we have attempted to exploit TRAIL sensitization by administering ex vivo-expanded autologous NK cells to patients with solid tumors or hematologic malignancies that have been pretreated with bortezomib. Ex vivo cultures used to expand clinical grade NK cells for this trial utilize irradiated EBV-LCL feeder cells and IL-2 containing media which upregulates surface expression of TRAIL, substantially augmenting NK cell killing of bortezomib-treated tumors in vitro. Here we characterize the impact of specific expansion conditions used to generate high numbers of NK cells for clinical use on NK cell TRAIL expression. Methods To generate clinical grade ex vivo-expanded NK cells, we first isolated NK cells from patient apheresis products by CD3+ depletion followed by CD56+ selection, and stimulated these enriched NK cells with irradiated EBV-LCL feeder cells at a ratio of 1:10 in X-VIVO 20 supplemented with 10% inactivated human AB serum and recombinant human IL-2 (500 IU/ml). The clinical trial evaluated 8 escalating NK cell dose levels (Figure 1). Cohorts 1-4 received a single infusion of ex vivo-expanded NK cells on day 0 in a dose-escalating fashion (3-6 pts per cohort) and cohorts 5-7 received 1 x 108 NK cells/kg on day 0 and a second escalating dose of NK cells infused on day +5. A "closed bag" Baxter PL732 culture system was used for cohorts 1-7 which was later changed to a GREX500-CS (Wilson Wolf) system in cohorts 7-8. Using flow cytometry, we monitored surface expression of TRAIL on the day NK cells were harvested and infused fresh into patients. We also assessed TRAIL expression on NK cells from a single patient cultured at 6 different cell densities (range: 2.03-16.95 x 106/cm2) using culture conditions mimicking the phase I trial. Results A total of 137 NK cell cultures were harvested and administered fresh to 32 patients. NK cells on the day of harvest expanded a median of 198-fold, 895-fold, and 3637-fold on culture days 14-16, 19-22, and 24-27, respectively. NK cells at harvest contained a median of 99.7% CD3−/CD56+ NK cells, were 68.65% CD16+ and had a median of 88% viability. TRAIL was assessed by mean fluorescence intensity (MFI) with a median surface expression of of 1245 (range 132-4913) at the time of infusion (Figure 1). Expansions for cohort 8 generated 10-14 x109 (1 vessel) and 50-70 x109 NK cells (4-5 vessels) for fresh infusion, enough to support the target dose level of 1x108 (1st harvest) and 5x108 (2nd harvest) NK cells/kg. Remarkably, NK cells grown at higher cell density to reach the target cell numbers for cohort 8 exhibited substantially reduced TRAIL expression (median: 255, range 132-691). Subsequent experiments conducted on NK cells expanded in vitro for 14 days at different cell densities/concentrations showed TRAIL expression (MFI range: 319-1627) inversely correlated with both cell density and concentration (Figure 2). NK cells grown at the highest cell density (16.95 x 106/cm2) and concentration (4.23 x 106/mL) expressed the least amount of TRAIL (MFI 319), in contrast to those cultured at the lowest cell density (2.03 x 106/cm2) and concentration (0.51 x 106/mL), which demonstrated a TRAIL MFI of 1627. Conclusions Although ex vivo cultures using feeder cells make it possible to expand large numbers of NK cells for clinical use in humans, the higher concentrations and density of cells in these cultures reduce NK cell surface expression of TRAIL. In vitro, TRAIL expression appears to inversely correlate with cell density. These data highlight the need to avoid overly concentrating ex vivo expanded NK cells to maximize TRAIL surface expression as a method to potentiate the anticancer effects of adoptively infused NK cells. Disclosures No relevant conflicts of interest to declare.

A TRAIL-TL1A paracrine network involving adipocytes, macrophages and lymphocytes induces adipose tissue dysfunction downstream of E2F1 in human obesity

Elevated expression of E2F1 in adipocyte-fraction of human visceral adipose-tissue(hVAT) associates with a poor cardio-metabolic profile. We hypothesized that beyond directly activating autophagy and MAP3K5(ASK)-MAP-kinase signaling, E2F1 governs a distinct transcriptome that contributes to adipose-tissue and metabolic dysfunction in obesity. We performed RNA-sequencing of hVAT samples from age-, sex- and BMI–matched patients, all obese, whose visceral-E2F1 protein expression was either high(E2F1^high) or low(E2F1^low). TNF-superfamily members, including <i>TRAIL</i>(<i>TNFSF10</i>), <i>TL1A</i>(<i>TNFSF15</i>) and their receptors were enriched in E2F1^high. While <i>TRAIL</i> was equally expressed in adipocytes and stromal-vascular fraction(SVF), <i>TL1A </i>was mainly expressed in SVF, and TRAIL-induced <i>TL1A</i> was attributed to CD4+ and CD8⁺-subclasses of hVAT T-lymphocytes. In human adipocytes TL1A enhanced basal and impaired insulin-inhibitable lipolysis, and altered adipokine secretion, and in human macrophages induced foam-cells biogenesis and M1-polarization. Two independent human cohorts confirmed associations between TL1A and TRAIL expression in hVAT and higher leptin and IL6 serum concentrations, diabetes status, and hVAT-macrophage lipid content. Jointly, we propose an intra-adipose tissue E2F1-associated TNF-superfamily paracrine loop engaging lymphocytes, macrophages and adipocytes, ultimately contributing to adipose-tissue dysfunction in obesity.

A TRAIL-TL1A paracrine network involving adipocytes, macrophages and lymphocytes induces adipose tissue dysfunction downstream of E2F1 in human obesity

Elevated expression of E2F1 in adipocyte-fraction of human visceral adipose-tissue(hVAT) associates with a poor cardio-metabolic profile. We hypothesized that beyond directly activating autophagy and MAP3K5(ASK)-MAP-kinase signaling, E2F1 governs a distinct transcriptome that contributes to adipose-tissue and metabolic dysfunction in obesity. We performed RNA-sequencing of hVAT samples from age-, sex- and BMI–matched patients, all obese, whose visceral-E2F1 protein expression was either high(E2F1^high) or low(E2F1^low). TNF-superfamily members, including <i>TRAIL</i>(<i>TNFSF10</i>), <i>TL1A</i>(<i>TNFSF15</i>) and their receptors were enriched in E2F1^high. While <i>TRAIL</i> was equally expressed in adipocytes and stromal-vascular fraction(SVF), <i>TL1A </i>was mainly expressed in SVF, and TRAIL-induced <i>TL1A</i> was attributed to CD4+ and CD8⁺-subclasses of hVAT T-lymphocytes. In human adipocytes TL1A enhanced basal and impaired insulin-inhibitable lipolysis, and altered adipokine secretion, and in human macrophages induced foam-cells biogenesis and M1-polarization. Two independent human cohorts confirmed associations between TL1A and TRAIL expression in hVAT and higher leptin and IL6 serum concentrations, diabetes status, and hVAT-macrophage lipid content. Jointly, we propose an intra-adipose tissue E2F1-associated TNF-superfamily paracrine loop engaging lymphocytes, macrophages and adipocytes, ultimately contributing to adipose-tissue dysfunction in obesity.

M1 Macrophages Promote TRAIL Expression in Adipose Tissue-Derived Stem Cells, Which Suppresses Colitis-Associated Colon Cancer by Increasing Apoptosis of CD133+ Cancer Stem Cells and Decreasing M2 Macrophage Population

We have previously reported that adipose tissue-derived stem cells (ASCs) cultured at high cell density can induce cancer cell death through the expression of type I interferons and tumor necrosis factor (TNF)-related apoptosis-inducing ligands (TRAIL). Here, we investigated whether TRAIL-expressing ASCs induced by M1 macrophages can alleviate colitis-associated cancer in an azoxymethane (AOM)/dextran sodium sulfate (DSS) animal model. M1 macrophages significantly increased the TRAIL expression in ASCs, which induced the apoptosis of LoVo cells in a TRAIL-dependent manner. However, CD133knockout LoVo cells, generated using the CRISPR-Cas9 gene-editing system, were resistant to TRAIL. In the AOM/DSS-induced colitis-associated cancer model, the intraperitoneal transplantation of TRAIL-expressing ASCs significantly suppressed colon cancer development. Moreover, immunohistochemical staining revealed a low CD133 expression in tumors from the AOM/DSS + ASCs group when compared with tumors from the untreated group. Additionally, the ASC treatment selectively reduced the number of M2 macrophages in tumoral (45.7 ± 4.2) and non-tumoral mucosa (30.3 ± 1.5) in AOM/DSS + ASCs-treated animals relative to those in the untreated group (tumor 71.7 ± 11.2, non-tumor 94.3 ± 12.5; p < 0.001). Thus, TRAIL-expressing ASCs are promising agents for anti-tumor therapy, particularly to alleviate colon cancer by inducing the apoptosis of CD133+ cancer stem cells and decreasing the M2 macrophage population.

Long noncoding RNA TANCR promotes γδ T cells activation by regulating TRAIL expression in cis

Background γδ T cells are an important subset of T lymphocytes that play important roles in innate and adaptive immunity via the secretion of various cytokines. Previous studies have found that long noncoding RNAs (lncRNAs) are critical regulators that contribute to the development of immune cells. However, the functions of lncRNAs in the γδ T cells remains poorly studied. Results Here, we identified the novel function of lncRNA NONHSAT196558.1 in isopentenyl pyrophosphate (IPP)-activated and -expanded γδ T cells using RNA-seq. As it functioned as an activating noncoding RNA of tumor necrosis factor related apoptosis-inducing ligand (TRAIL), an important cytotoxic cytokine that expressed by γδ T cells in responding to various infectious agents, we named this lncRNA as TANCR. Secondly, the expression of TANCR was found to be positively correlated with TRAIL expression in IPP activated γδ T cells. In addition, TANCR was confirmed to localized both in nucleus and cytoplasm. Finally, a loss-of-function was conducted by using siRNA/ASO or CRISPR/Cas9 system to knockdown or knockout TANCR, and confirmed that silencing of TANCR inhibits TRAIL expression in several kinds of cells, including HEK293T cells, Jurkat cells, and primary γδ T cells. Conclusion These evidences demonstrate that TANCR play important roles in γδ T cell activation. Furthermore, TANCR may be involved in the cytotoxicity of γδ T cells. This study aims to further our understanding of the molecular mechanisms underlying lncRNA-mediated immune responses.