Tumor Necrosis Factor Superfamily 15 Research Articles

TNFSF15 facilitates the differentiation of CD11b+ myeloid cells into vascular pericytes in tumors.

Immature vasculature lacking pericyte coverage substantially contributes to tumor growth, drug resistance, and cancer cell dissemination. We previously demonstrated that tumor necrosis factor superfamily 15 (TNFSF15) is a cytokine with important roles in modulating hematopoiesis and vascular homeostasis. The main purpose of this study was to explore whether TNFSF15 might promote freshly isolated myeloid cells to differentiate into CD11b+ cells and further into pericytes. A model of Lewis lung cancer was established in mice with red fluorescent bone marrow. After TNFSF15 treatment, CD11b+ myeloid cells and vascular pericytes in the tumors, and the co-localization of pericytes and vascular endothelial cells, were assessed. Additionally, CD11b+ cells were isolated from wild-type mice and treated with TNFSF15 to determine the effects on the differentiation of these cells. We observed elevated percentages of bone marrow-derived CD11b+ myeloid cells and vascular pericytes in TNFSF15-treated tumors, and the latter cells co-localized with vascular endothelial cells. TNFSF15 protected against CD11b+ cell apoptosis and facilitated the differentiation of these cells into pericytes by down-regulating Wnt3a-VEGFR1 and up-regulating CD49e-FN signaling pathways. TNFSF15 facilitates the production of CD11b+ cells in the bone marrow and promotes the differentiation of these cells into pericytes, which may stabilize the tumor neovasculature.

TNFSF15 facilitates differentiation and polarization of macrophages toward M1 phenotype to inhibit tumor growth

ABSTRACT Macrophages of the M2 phenotype in malignant tumors significantly aid tumor progression and metastasis, as opposed to the M1 phenotype that exhibits anti-cancer characteristics. Raising the ratio of M1/M2 is thus a promising strategy to ameliorate the tumor immunomicroenvironment toward cancer inhibition. We report here that tumor necrosis factor superfamily-15 (TNFSF15), a cytokine with anti-angiogenic activities, is able to facilitate the differentiation and polarization of macrophages toward M1 phenotype. We found that tumors formed in mice by Lewis lung carcinoma (LLC) cells artificially overexpressing TNFSF15 exhibited retarded growth. The tumors displayed a greater percentage of M1 macrophages than those formed by mock-transfected LLC cells. Treatment of mouse macrophage RAW264.7 cells with recombinant TNFSF15 led to augmentation of the phagocytic and pro-apoptotic capacity of the macrophages against cancer cells. Mechanistically, TNFSF15 activated STAT1/3 in bone marrow cells and MAPK, Akt and STAT1/3 in naive macrophages. Additionally, TNFSF15 activated STAT1/3 but inactivated STAT6 in M2 macrophages. Modulations of these signals gave rise to a reposition of macrophage phenotypes toward M1. The ability of TNFSF15 to promote macrophage differentiation and polarization toward M1 suggests that this unique cytokine may have a utility in the reconstruction of the immunomicroenvironment in favor of tumor suppression.

A Protective Role of Tumor Necrosis Factor Superfamily-15 in Intracerebral Hemorrhage-Induced Secondary Brain Injury.

Destabilization of blood vessels by the activities of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) following intracerebral hemorrhage (ICH) has been considered the main causes of aggravated secondary brain injury. Here, we show that tumor necrosis factor superfamily-15 (TNFSF15; also known as vascular endothelial growth inhibitor), an inhibitor of VEGF-induced vascular hyper-permeability, when overexpressed in transgenic mice, exhibits a neuroprotective function post-ICH. In this study, we set-up a collagenase-induced ICH model with TNFSF15-transgenic mice and their transgene-negative littermates. We observed less lesion volume and neural function perturbations, together with less severe secondary injuries in the acute phase that are associated with brain edema and inflammation, including vascular permeability, oxidative stress, microglia/macrophage activation and neutrophil infiltration, and neuron degeneration, in the TNFSF15 group compared with the littermate group. Additionally, we show that there is an inhibition of VEGF-induced elevation of MMP-9 in the perihematomal blood vessels of the TNFSF15 mice following ICH, concomitant with enhanced pericyte coverage of the perihematomal blood vessels. These findings are consistent with the view that TNFSF15 may have a potential as a therapeutic agent for the treatment of secondary injuries in the early phase of ICH.

Signaling in TNFSF15-mediated Suppression of VEGF Production in Endothelial Cells.

Vascular endothelial growth factor (VEGF) plays a pivotal role in promoting neovascularization. Tumor necrosis factor superfamily 15 (TNFSF15) is an antiangiogenic cytokine prominently produced by endothelial cells in a normal vasculature. In this study, Western blot, quantitative polymerase chain reaction (qPCR), and dual luciferase reporter gene assay were used to validate the mechanisms of TNFSF15-mediated suppression of VEGF production in endothelial cells. We report that TNFSF15 inhibits VEGF production via microRNA-29b (miR-29b) targeting the 3'-UTR of VEGF transcript in mouse endothelial cell line bEnd.3. Neutralizing antibody against TNFSF15, 4-3H, inhibits the level of miR-29b and reinvigorates VEGF. In addition, TNFSF15 activates the JNK signaling pathway as well as the transcription factor GATA3, resulting in enhanced miR-29b production. SP600125, an inhibitor of JNK, eradicates TNFSF15-induced GATA3 expression. Moreover, GATA3 siRNA suppressed TNFSF15-induced miR-29b expression. Together, this study provides evidence and method of activation of the JNK-GATA3 signaling pathway by TNFSF15 that suppresses VEGF gene expression, which gives rise to upregulation of miR-29b.

Polymorphism rs6478109 in the TNFSF15 gene contributes to the susceptibility to Crohn's disease but not ulcerative colitis: a meta-analysis.

ObjectivePolymorphisms in the tumor necrosis factor superfamily 15 (TNFSF15) gene contribute to susceptibility to inflammatory bowel disease (IBD). However, associations between TNFSF15 rs6478109, rs7869487, and rs7865494 polymorphisms and IBD remain unclear.MethodsEligible articles were retrieved from the PubMed, EMBASE, Web of Science, and CNKI databases through 20 March 2020. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the relationships of TNFSF15 polymorphisms with IBD susceptibility.ResultsUnder the recessive model, TNFSF15 rs6478109 was associated with IBD risk (OR = 0.56; 95% CI: 0.35, 0.92). Stratification analyses based on the type of disease—Crohn’s disease (CD) or ulcerative colitis (UC)—revealed a significant association under the allelic and recessive models between TNFSF15 rs6478109 and CD (allelic model: OR = 0.84, 95% CI: 0.71, 0.99; recessive model: OR = 0.44, 95% CI: 0.22, 0.87) but not UC. Stratification by ethnicity indicated a significantly decreased risk of IBD in Asian populations with TNFSF15 rs6478109 under the recessive model (OR = 0.56, 95% CI: 0.35, 0.92).ConclusionsOur meta-analysis suggested that under the allelic and recessive models, the TNFSF15 rs6478109 polymorphism was likely protective for CD but not UC in the Asian population.

TNFSF15 Polymorphisms are Associated with Graves’ Disease and Graves’ Ophthalmopathy in a Han Chinese Population

ABSTRACT Purpose Previous studies revealed an association of tumor necrosis factor super family-15 (TNFSF15) gene polymorphisms with several autoimmune diseases, but their roles in the development of Graves’ disease (GD) and Graves’ ophthalmopathy (GO) remain unclear. The aim of this study was to explore the correlation between TNFSF15 single nucleotide polymorphisms (SNPs) and susceptibility to GD and GO in a Han Chinese population. Materials and Methods This case-control study enrolled 813 healthy controls and 315 GD patients including 229 patients with GO. Eight SNPs of TNFSF15 (rs3810936, rs6478108, rs6478106, rs4979462, rs10817669, rs4246905, rs10733612, and rs10759734) were detected by TaqMan real-time PCR assay or PCR-restriction fragment length polymorphism (PCR-RFLP) and the possible association of these eight SNPs with the risk of GD and GO was analyzed. Allele frequencies and genotype distributions were compared using χ2 test. A stratified analysis was also performed according to clinical activity score (CAS) and sex. Results In comparison with the controls, the CT genotype of rs3810936 and the T allele of rs4979462 were decreased in GD patients. GD patients with GO also showed a lower frequency of the rs3810936 CT genotype and the rs4979462 T allele than the controls. Inactive GO patients showed a lower frequency of the rs3810936 CT genotype than controls, while GD females demonstrated a lower incidence of the T allele in rs4979462 and rs6478106 than the controls. Furthermore, GO females exhibited a lower rate of the rs4979462 T allele than the controls. Conclusions Our results suggest that TNFSF15 rs3810936 and rs4979462 polymorphisms are associated with the susceptibility of GD and GO in a Han Chinese population. Additionally, rs3810936 may affect the activity of GO, and rs4979462 may correlate with the sexual dimorphism observed in GD and GO.

Tumor necrosis factor superfamily 15 promotes lymphatic metastasis via upregulation of vascular endothelial growth factor-C in a mouse model of lung cancer.

Lymphatic metastasis is facilitated by lymphangiogenic growth factor vascular endothelial growth factor‐C (VEGFC) that is secreted by some primary tumors. We previously identified tumor necrosis factor superfamily 15 (TNFSF15), a blood vascular endothelium‐derived cytokine, in lymphatic endothelial cells, as a key molecular modulator during lymphangiogenesis. However, the effect of TNFSF15 on tumor lymphatic metastasis and the underlying molecular mechanisms remain unclear. We report here that TNFSF15, which is known to inhibit primary tumor growth by suppressing angiogenesis, can promote lymphatic metastasis through facilitating lymphangiogenesis in tumors. Mice bearing tumors induced by A549 cells stably overexpressing TNFSF15 exhibited a significant increase in densities of lymphatic vessels and a marked enhancement of A549 tumor cells in newly formed lymphatic vessels in the primary tumors as well as in lymph nodes. Treatment of A549 cells with TNFSF15 results in upregulation of VEGFC expression, which can be inhibited by siRNA gene silencing of death domain‐containing receptor‐3 (DR3), a cell surface receptor for TNFSF15. In addition, TNFSF15/DR3 signaling pathways in A549 cells include activation of NF‐κB during tumor lymphangiogenesis. Our data indicate that TNFSF15, a cytokine mainly produced by blood endothelial cells, facilitates tumor lymphangiogenesis by upregulating VEGFC expression in A549 cells, contributing to lymphatic metastasis in tumor‐bearing mice. This finding also suggests that TNFSF15 may have potential as an indicator for prognosis evaluation.

TNFSF15 Inhibits Blood Retinal Barrier Breakdown Induced by Diabetes.

Tumor necrosis factor superfamily 15 (TNFSF15) is an endogenous neovascularization inhibitor and an important negative regulator of vascular homeostasis. This study aimed to explore the potential role of TNFSF15 in diabetic retinopathy. Vitreous TNFSF15 and VEGF levels in proliferative diabetic retinopathy (PDR) patients were detected by ELISA. Retinal expression of TNFSF15 and the content of tight junction proteins (TJPs) in rats were detected by immunohistochemistry and Western blot, respectively. The blood retinal barrier (BRB) permeability was evaluated using Evans Blue (EB) dye. The TNFSF15/VEGF ratio was decreased in the vitreous fluid of patients with PDR relative to the controls, even though the expression levels of TNFSF15 were higher. TNFSF15 was dramatically decreased one month later after diabetes induction (p < 0.001), and then increased three months later and thereafter. TNFSF15 treatment significantly protected the BRB in the diabetic animals. Diabetes decreased TJPs levels in the retina, and these changes were inhibited by TNFSF15 treatment. Moreover, TNFSF15 decreased activation of VEGF both in mRNA and protein levels caused by diabetes. These results indicate that TNFSF15 is an important inhibitor in the progression of DR and suggest that the regulation of TNFSF15 shows promise for the development of diabetic retinopathy treatment strategies.

Protective association of tumor necrosis factor superfamily 15 (TNFSF15) polymorphic haplotype with Ulcerative Colitis and Crohn's disease in an Indian population.

BackgroundTumor necrosis factor superfamily (TNFSF) proteins are involved in the genesis of inflammatory bowel disease (IBD). We examined the association of seven single nucleotide polymorphisms (SNP) in the TNFSF15 gene with Crohn's disease (CD) and ulcerative colitis (UC) in the Indian population.MethodsSeven SNPs in the TNFSF15 gene (rs10114470, rs3810936, rs6478108, rs4263839, rs6478109, rs7848647 and rs7869487) were genotyped in 309 CD patients, 330 UC patients and 437 healthy controls using the Sequenom iPLEX MassArray platform. Disease associations were evaluated for allelotypes and for genotypes.ResultsThe minor T alleles and the TT genotypes of rs10114470 and rs3810936 were significantly protectively associated with both CD and UC. The CC genotype of rs6478108, AA genotype of rs4263839, the AA genotype of rs6478109, the TT genotype of rs7848647 and the CC genotype of rs7869487 were all protectively associated with CD but not with UC. Two haplotype blocks could be discerned, one where SNPs rs10114470 and rs3810936 were in tight LD (D′ = 0.8) and the other where rs6478108, rs4263839, rs6478109, rs7848647 and rs7869487 were in tight LD (D′ 0.92–1.00). The second block of haplotypes were not associated with CD or with UC. The first block of haplotypes was very significantly associated with both CD and UC.ConclusionsStrong associations exist between TNFSF15 gene polymorphisms and IBD (both CD and UC) in the Indian population.

Abstract 22: Interferon-γ produced by tumor-infiltrating NK cells and CD4+ T cells downregulates TNFSF15 expression in endothelial cells

Abstract Endothelial cells in an established vasculature secrete tumor necrosis factor superfamily-15 (TNFSF15; VEGI; TL1A) that functions as a negative modulator of neovascularization to maintain blood vessel stability. TNFSF15 gene expression diminishes at angiogenesis and inflammation sites such as in cancers and wounds. Interferon-γ (IFNγ) is a pleiotropic cytokine expressed primarily by lymphocytes of T cell and NK cell lineages. IFNγ may mediate anti-tumor effects either directly on cancer cell growth or indirectly through immunomodulatory and antiangiogenic responses. However, it was also reported that IFNγ promotes angiogenesis under certain circumstances. Here we show that IFNγ suppresses TNFSF15 expression in human umbilical cord vein endothelial cells (HUVEC). This activity is mediated by IFNγ receptor and the transcription factor STAT1. Since tumor-infiltrating NK and CD4+ T cells are the main sources of IFNγ in tumor lesions, we isolated these cells from peripheral blood of healthy individuals, treated the cells with ovarian cancer OVCAR3 cell-conditioned media, and found a 1- and 10-fold increase of IFNγ production in NK and CD4+ T cells, respectively, compared with that in vehicle-treated cells. These findings support the view that tumor-infiltrating NK and CD4+ T cells under the influence of cancer cells significantly increase the production of IFNγ, which in turn inhibits TNFSF15 expression in tumor vascular endothelial cells, shifting the balance of pro- and anti-angiogenic factors toward escalated angiogenesis potential in the tumor. Citation Format: Xin Gu, Tao Cheng, Luyuan Li. Interferon-γ produced by tumor-infiltrating NK cells and CD4+ T cells downregulates TNFSF15 expression in endothelial cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 22. doi:10.1158/1538-7445.AM2014-22

Tumor necrosis factor-superfamily 15 gene expression in patients with sickle cell disease.

Objective: The aim of this study was to investigate the relation between tumor necrosis factor-superfamily 15 (TNFSF15) gene expression and clinical findings in children with sickle cell disease (SCD). Materials and Methods: Forty-nine patients with SCD and 38 healthy controls were included in this study. TNFSF15 gene expression and plasma levels were analyzed. TNFSF15 gene expression was compared in subgroups considering the frequency of painful crises and acute chest syndrome (ACS). Results: It was found that TNFSF15 gene expression was significantly higher in patients with SCD than the controls (p=0.001), whereas there was no significant difference between the patients with SCD and the control groups considering plasma levels of TNFSF15. TNFSF15 gene expression was also significantly higher in SCD patients with ACS (p=0.008). Conclusion: These findings suggest that TNFSF15 may have a role in the pathogenesis of SCD presenting with ACS. Further studies on larger groups are needed to determine the function of TNFSF15 in SCD patients with ACS and pulmonary hypertension. Analysis of TNFSF15 expression may also serve as a promising approach in ACS therapy.

Death receptor 3 mediates TNFSF15- and TNFα-induced endothelial cell apoptosis

Tumor necrosis factor superfamily 15 (TNFSF15) suppresses angiogenesis by specifically inducing apoptosis in proliferating endothelial cells. Death receptor 3 (DR3), a member of the TNF receptor superfamily (TNFRSF25), has been identified as a receptor for TNFSF15 to activate T cells. It is unclear, however, whether DR3 mediates TNFSF15 activity on endothelial cells. Here we show that siRNA-mediated knockdown of DR3 in an in vivo Matrigel angiogenesis assay, or in adult bovine aortic endothelial (ABAE) cell cultures, leads to resistance of endothelial cells to TNFSF15-induced apoptosis. Interestingly, DR3-depleted cells also exhibited markedly diminished responsiveness to TNFα cytotoxicity, even though DR3 is not a receptor for TNFα. Treatment of the cells with either TNFSF15 siRNA or a TNFSF15-neutralizing antibody, 4-3H, also results in a significant inhibition of TNFα-induced apoptosis. Mechanistically, DR3 siRNA treatment gives rise to an increase of ERK1/2 MAPK activity, and up-regulation of the anti-apoptotic proteins c-FLIP and Bcl-2, thus strengthening apoptosis-resisting potential in the cells. These findings indicate that DR3 mediates TNFSF15-induced endothelial cell apoptosis, and that up-regulation of TNFSF15 expression stimulated by TNFα is partly but significantly responsible for TNFα-induced apoptosis in endothelial cells.

Effects of salinomycin and Bacillus subtilis on growth performance and immune responses in broiler chickens

The present study was undertaken to compare the effect of salinomycin and Bacillus subtilis on growth performance, serum antibody levels against Clostridium spp. and Eimeria spp., and cytokine mRNA expression levels in broiler chickens raised in the used litter. Broiler chickens fed a diet containing salinomycin showed lower (P < 0.05) body weights compared with the control diet-fed counterparts. Serum nitric oxide levels were significantly (P < 0.05) elevated in chickens fed the B. subtilis-enriched diet compared with those on either the salinomycin-fed or control diet-fed chickens. None of the dietary treatments affected (P > 0.05) serum antibody levels against Clostridium perfringens toxins. Both salinomycin and B. subtilis significantly lowered (P < 0.05) the serum levels of Eimeria-specific antibodies compared with the control group. Salinomycin, but not B. subtilis, significantly modulated (P < 0.05) the expression of cytokines encoding interferon-γ (IFN-γ), interleukin10 (IL-10) and tumor necrosis factor superfamily 15 (TNFSF15) compared with the control group. In conclusion, dietary salinomycin and B. subtilis affected serum anticoccidial antibody and intestinal cytokine expression, but failed to improve growth performance in broiler chickens. Further study is warranted to investigate the mode of action of salinomycin on host immune response and growth performance in broiler chickens.

Interferon-γ produced by tumor-infiltrating NK cells and CD4+ T cells downregulates TNFSF15 expression in vascular endothelial cells

Endothelial cells in an established vasculature secrete tumor necrosis factor superfamily-15 (TNFSF15; VEGI; TL1A) that functions as a negative modulator of neovascularization to maintain blood vessel stability. TNFSF15 gene expression diminishes at angiogenesis and inflammation sites such as in cancers and wounds. We reported previously that vascular endothelial growth factor and monocyte chemotactic protein-1 contribute to TNFSF15 downmodulation in ovarian cancer. Here we show that interferon-γ (IFNγ) suppresses TNFSF15 expression in human umbilical vein endothelial cells. This activity is mediated by IFNγ receptor and the transcription factor STAT1. Immunohistochemical analysis of ovarian cancer clinical specimens indicates that TNFSF15 expression diminishes while tumor vascularity increases in specimens with high-grades of IFNγ expression. Since tumor-infiltrating NK and CD4(+) T cells are the main sources of IFNγ in tumor lesions, we isolated these cells from peripheral blood of healthy individuals, treated the cells with ovarian cancer OVCAR3 cell-conditioned media, and found a onefold and tenfold increase of IFNγ production in NK and CD4(+) T cells, respectively, compared with that in vehicle-treated cells. These findings support the view that tumor-infiltrating NK and CD4(+) T cells under the influence of cancer cells significantly increase the production of IFNγ, which in turn inhibits TNFSF15 expression in vascular endothelial cells, shifting the balance of pro- and anti-angiogenic factors toward escalated angiogenesis potential in the tumor.

TNFSF15 inhibits vasculogenesis by regulating relative levels of membrane-bound and soluble isoforms of VEGF receptor 1

Mouse bone marrow-derived Lin(-)-Sca-1(+) endothelial progenitor cell (EPC) has pluripotent abilities such as supporting neovascularization. Vascular endothelial growth factor (VEGF) receptor 1 (VEGFR1) (Flt1) recognizes various VEGF isoforms and is critically implicated in a wide range of physiological and pathological settings, including vasculogenesis. Mouse EPC expresses two isoforms of VEGFR1: mFlt1, which transmits ligand-induced signals; and sFlt1, which acts as a negative regulator by sequestering ligands of VEGF receptors. How the relative levels of mFlt1 and sFlt1 are regulated is not yet clear. We report here that tumor necrosis factor superfamily 15 (TNFSF15) (also known as VEGI or TL1A), an endothelial cell-secreted cytokine, simultaneously promotes mFlt1 degradation and up-regulates sFlt1 expression in EPC, giving rise to disruption of VEGF- or PlGF-induced activation of eNOS and MAPK p38 and effective inhibition of VEGF-driven, EPC-supported vasculogenesis in a murine Matrigel implant model. TNFSF15 treatment of EPC cultures facilitates Akt deactivation-dependent, ubiquitin-assisted degradation of mFlt1 and stimulates sFlt1 expression by activating the PKC, Src, and Erk1/2 signaling pathway. Additionally, TNFSF15 promotes alternative splicing of the Flt1 gene in favor of sFlt1 production by down-regulating nuclear protein Jumonji domain-containing protein 6 (Jmjd6), thus alleviating Jmjd6-inhibited sFlt1 expression. These findings indicate that TNFSF15 is a key component of a molecular mechanism that negatively modulates EPC-supported vasculogenesis through regulation of the relative levels of mFlt1 and sFlt1 in EPC.

TNFSF15 Modulates Neovascularization and Inflammation

Tumor necrosis factor superfamily-15 (TNFSF15; also known as VEGI or TL1A) is a unique cytokine that functions in the modulation of vascular homeostasis and inflammation. TNFSF15 is expressed abundantly in established vasculature but is down-regulated at sites of neovascularization such as in cancers and wounds. TNFSF15 inhibits endothelial cell proliferation and endothelial progenitor cell differentiation. Additionally, TNFSF15 stimulates T cell activation, Th1 cytokine production, and dendritic cell maturation. Some of the functions of TNFSF15 are mediated by death receptor-3. We review the experimental evidences on TNFSF15 activities in angiogenesis, vasculogenesis, inflammation, and immune system mobilization.

Down-modulation of TNFSF15 in ovarian cancer by VEGF and MCP-1 is a pre-requisite for tumor neovascularization

Persistent inflammation and neovascularization are critical to cancer development. In addition to upregulation of positive control mechanisms such as overexpression of angiogenic and inflammatory factors in the cancer microenvironment, loss of otherwise normally functioning negative control mechanisms is likely to be an important attribute. Insights into the down-modulation of such negative control mechanisms remain largely unclear, however. We show here that tumor necrosis factor superfamily-15 (TNFSF15), an endogenous inhibitor of neovascularization, is a critical component of the negative control mechanism that operates in normal ovary but is missing in ovarian cancer. We show in clinical settings that TNFSF15 is present prominently in the vasculature of normal ovary but diminishes in ovarian cancer as the disease progresses. Vascular endothelial growth factor (VEGF) produced by cancer cells and monocyte chemotactic protein-1 (MCP-1) produced mainly by tumor-infiltrating macrophages and regulatory T cells effectively inhibits TNFSF15 production by endothelial cells in vitro. Using a mouse syngeneic tumor model, we demonstrate that silencing TNFSF15 by topical shRNA treatments prior to and following mouse ovarian cancer ID8 cell inoculation greatly facilitates angiogenesis and tumor growth, whereas systemic application of recombinant TNFSF15 inhibits angiogenesis and tumor growth. Our findings indicate that downregulation of TNFSF15 by cancer cells and tumor infiltrating macrophages and lymphocytes is a pre-requisite for tumor neovascularization.

In vitro effects of plant and mushroom extracts on immunological function of chicken lymphocytes and macrophages

1. The present study was conducted to examine the effects of organic extracts from milk thistle (Silybum marianum), turmeric (Curcuma longa), reishi mushroom (Ganoderma lucidum), and shiitake mushroom (Lentinus edodes) on innate immunity and tumor cell viability. 2. Innate immunity was measured by lymphocyte proliferation and nitric oxide production by macrophages, and the inhibitory effect on tumor cell growth was assessed using a non-radioactive assay. For measuring the cytokine levels in the HD11 macrophages which were treated with extracts of turmeric or shiitake mushroom, the levels of mRNAs for interferon-α (IFN- α), interleukin-1β (IL-1β), IL-6, IL-12, IL-15, IL-18, and tumor necrosis factor superfamily 15 (TNFSF15) were quantified by real time RT-PCR. 3. In vitro culture of chicken spleen lymphocytes with extracts of milk thistle, turmeric, and shiitake and reishi mushrooms induced significantly higher cell proliferation compared with the untreated control cells. Stimulation of macrophages with extracts of milk thistle and shiitake and reishi mushrooms, but not turmeric, resulted in robust nitric oxide production to levels that were similar with those induced by recombinant chicken interferon-γ. All extracts uniformly inhibited the growth of chicken tumor cells in vitro at the concentration of 6·3 through 100 µg/ml. Finally, the levels of mRNAs encoding IL-1β, IL-6, IL-12, IL-18, and TNFSF15 were enhanced in macrophages that were treated with extracts of turmeric or shiitake mushroom compared with the untreated control. 4. These results document the immunologically-based enhancement of innate immunity in chickens by extracts of plants and mushrooms with known medicinal properties in vitro. In vivo studies are being planned to delineate the cellular and molecular mechanisms responsible for their mechanism of action.

The Role of TNFSF15 in the Modulation of Neovascularization and Inflammation

Tumor necrosis factor super family 15 (TNFSF15) is one of the more recently identified TNF ligands. Emerging studies are beginning to reveal the function of TNFSF15 in physiology and pathology. TNFSF15 has been found to have a prominent role in endothelial cell biology. The abundance of TNFSF15 in the vasculature suggests that the endothelium be the major production site of this cytokine. TNFSF15 has been shown to be a negative regulator of angiogenesis with a unique characteristic of inhibiting proliferation only on endothelial cells. In addition, TNFSF15 is also involved in the modulation of inflammation. It stimulates T cell activation, Th1 cytokine production, and dendritic cell maturation. Thus, similar to other TNF ligands, TNFSF15 is a multifunctional, yet specialized, cytokine. The various functions of TNFSF15 are mostly mediated by death receptor 3 (DR3). We review the experimental evidences on the identification, isoforms, structure and expression of TNFSF15, and its activities in anti-angiogenesis, anti-tumor, inflammation and immune system mobilization. Keywords: TNFSF15, VEGI, TL1A, cytokine

Characterization of chicken TNFSF15 and it’s role in coccidiosis (96.10)

Abstract A full-length cDNA encoding chicken tumor necrosis factor superfamily 15 (TNFSF15) was isolated and its functional role was investigated. TNFSF15 transcripts were primarily expressed in spleen, liver, intestinal intraepithelial lymphocytes (IEL), peripheral blood lymphocytes and bursa. In vitro infection of HTC macrophages with three species of Eimeria sporozoites induced TNFSF15 gene expression. In vivo experiments revealed that TNFSF15 gene was highly increased following primary infections with E. acervulina or E. maxima. In contrast, no consistent changes in transcript levels were seen following primary infection with E. tenella, or following secondary infection with any of the three Eimeria species. Following infection with E. acervulina and E. maxima, TNFSF15 transcripts were primarily expressed in intestinal CD4+ and TCR2+ IEL, respectively. A dose-dependent cytotoxic effect of recombinant TNFSF15 protein was observed on HTC and LSCC-RP9 tumor cells. These results indicate that TNFSF15 plays an important role in the local inflammatory response to Eimeria.