Tumor necrosis factor receptor superfamily members and their ligands

Auto-loaded TRAIL-exosomes derived from induced neural stem cells for brain cancer therapy

Transdifferentiation (TD), a somatic cell reprogramming process that eliminates pluripotent intermediates, creates cells that are ideal for personalized anti-cancer therapy. Here, we provide the first evidence that extracellular vesicles (EVs) from TD-derived induced neural stem cells (Exo-iNSCs) are an efficacious treatment strategy for brain cancer. We found that genetically engineered iNSCs generated EVs loaded with the tumoricidal gene product TRAIL at nearly twice the rate of their parental fibroblasts, and TRAIL produced by iNSCs was naturally loaded into the lumen of EVs and arrayed across their outer membrane (Exo-iNSC-TRAIL). Uptake studies in ex vivo organotypic brain slice cultures showed that Exo-iNSC-TRAIL selectively accumulates within tumor foci, and co-culture assays demonstrated that Exo-iNSC-TRAIL killed metastatic and primary brain cancer cells more effectively than free TRAIL. In an orthotopic mouse model of brain cancer, Exo-iNSC-TRAIL reduced breast-to-brain tumor xenografts by approximately 3000-fold compared to treatment with free TRAIL, with all Exo-iNSC-TRAIL treated animals surviving through 90 days post-treatment. In additional in vivo testing against aggressive U87 and invasive GBM8 glioblastoma tumors, Exo-iNSC-TRAIL also induced a statistically significant increase in survival. These studies establish a novel, easily generated, stable, tumor-targeted EV to efficaciously treat multiple forms of brain cancer.

Auto-loaded TRAIL-exosomes derived from induced neural stem cells for brain cancer therapy

Transdifferentiation (TD), a somatic cell reprogramming process that eliminates pluripotent intermediates, creates cells that are ideal for personalized anti-cancer therapy. Here, we provide the first evidence that extracellular vesicles (EVs) from TD-derived induced neural stem cells (Exo-iNSCs) are an efficacious treatment strategy for brain cancer. We found that genetically engineered iNSCs generated EVs loaded with the tumoricidal gene product TRAIL at nearly twice the rate as their parental fibroblasts, and the TRAIL produced by iNSCs were naturally loaded into the lumen of EVs and arrayed across their outer membrane (Exo-iNSC-TRAIL). Uptake studies in ex vivo organotypic brain slice cultures showed Exo-iNSC-TRAIL selectively accumulates within tumor foci, and co-culture assays showed that Exo-iNSC-TRAIL killed metastatic and primary brain cancer cells more effectively than free TRAIL. In an orthotopic mouse model of brain cancer, Exo-iNSC-TRAIL reduced breast-to-brain tumor xenografts around 3000-fold greater than treatment with free TRAIL, with all Exo-iNSC-TRAIL treated animals surviving through 90 days post-treatment. In additional in vivo testing against aggressive U87 and invasive GBM8 glioblastoma tumors, Exo-iNSC-TRAIL also induced a statistically significant increase in survival. These studies establish a new easily generated, stable, tumor-targeted EV to efficaciously treat multiple forms of brain cancer.

A systems and computational biology perspective on advancing CAR therapy

In the recent decades, chimeric antigen receptor (CAR) therapy signaled a new revolutionary approach to cancer treatment. This method seeks to engineer immune cells expressing an artificially designed receptor, which would endue those cells with the ability to recognize and eliminate tumor cells. While some CAR therapies received FDA approval and others are subject to clinical trials, many aspects of their workings remain elusive. Techniques of systems and computational biology have been frequently employed to explain the operating principles of CAR therapy and suggest further design improvements. In this review, we sought to provide a comprehensive account of those efforts. Specifically, we discuss various computational models of CAR therapy ranging in scale from organismal to molecular. Then, we describe the molecular and functional properties of costimulatory domains frequently incorporated in CAR structure. Finally, we describe the signaling cascades by which those costimulatory domains elicit cellular response against the target. We hope that this comprehensive summary of computational and experimental studies will further motivate the use of systems approaches in advancing CAR therapy.

Targeting 4-1BB for tumor immunotherapy from bench to bedside

Immune dysfunction has been proposed as a factor that may contribute to disease progression. Emerging evidence suggests that immunotherapy aims to abolish cancer progression by modulating the balance of the tumor microenvironment. 4-1BB (also known as CD137 and TNFRS9), a member of tumor necrosis factor receptor superfamily, has been validated as an extremely attractive and promising target for immunotherapy due to the upregulated expression in the tumor environment and its involvement in tumor progression. More importantly, 4-1BB-based immunotherapy approaches have manifested powerful antitumor effects in clinical trials targeting 4-1BB alone or in combination with other immune checkpoints. In this review, we will summarize the structure and expression of 4-1BB and its ligand, discuss the role of 4-1BB in the microenvironment and tumor progression, and update the development of drugs targeting 4-1BB. The purpose of the review is to furnish a comprehensive overview of the potential of 4-1BB as an immunotherapeutic target and to discuss recent advances and prospects for 4-1BB in cancer therapy.

TRAIL/DR5 pathway promotes AKT phosphorylation, skeletal muscle differentiation, and glucose uptake

TNF-related apoptosis-inducing ligand (TRAIL) is a protein that induces apoptosis in cancer cells but not in normal ones, where its effects remain to be fully understood. Previous studies have shown that in high-fat diet (HFD)-fed mice, TRAIL treatment reduced body weight gain, insulin resistance, and inflammation. TRAIL was also able to increase skeletal muscle free fatty acid oxidation. The aim of the present work was to evaluate TRAIL actions on skeletal muscle. Our in vitro data on C2C12 cells showed that TRAIL treatment significantly increased myogenin and MyHC and other hallmarks of myogenic differentiation, which were reduced by Dr5 (TRAIL receptor) silencing. In addition, TRAIL treatment significantly increased AKT phosphorylation, which was reduced by Dr5 silencing, as well as glucose uptake (alone and in combination with insulin). Our in vivo data showed that TRAIL increased myofiber size in HFD-fed mice as well as in db/db mice. This was associated with increased myogenin and PCG1α expression. In conclusion, TRAIL/DR5 pathway promotes AKT phosphorylation, skeletal muscle differentiation, and glucose uptake. These data shed light onto a pathway that might hold therapeutic potential not only for the metabolic disturbances but also for the muscle mass loss that are associated with diabetes.

Cancer immune therapy with PD-1-dependent CD137 co-stimulation provides localized tumour killing without systemic toxicity

Expression of the cell surface receptor CD137 has been shown to enhance anti-cancer T cell function via engagement with its natural ligand 4-1BBL. CD137 ligation with engineered ligands has emerged as a cancer immunotherapy strategy, yet clinical development of agonists has been hindered by either toxicity or limited efficacy. Here we show that a CD137/PD-1 bispecific antibody, IBI319, is able to overcome these limitations by coupling CD137 activation to PD-1-crosslinking. In CT26 and MC38 syngeneic mouse tumour models, IBI319 restricts T cell co-stimulation to PD-1-rich microenvironments, such as tumours and tumour-draining lymph nodes, hence systemic (liver) toxicity arising from generalised T cell activation is reduced. Besides limiting systemic T cell co-stimulation, the anti-PD-1 arm of IBI319 also exhibits checkpoint blockade functions, with an overall result of T and NK cell infiltration into tumours. Toxicology profiling in non-human primates shows that IBI319 is a well-tolerated molecule with IgG-like pharmacokinetic properties, thus a suitable candidate for further clinical development.

The toxicity arising from generalised stimulation of T cells restricts applicability of CD137 agonists in cancer immune therapy. Here authors show that a bispecific antibody blocking PD-1 while activating CD137 efficiently restricts T cell activation to the tumour microenvironment, resulting in efficient tumour control and reduced liver toxicity.

Designed ferritin nanocages displaying trimeric TRAIL and tumor-targeting peptides confer superior anti-tumor efficacy

TRAIL is considered a promising target for cancer therapy because it mediates activation of the extrinsic apoptosis pathway in a tumor-specific manner by binding to and trimerizing its functional receptors, DR4 or DR5. Although recombinant human TRAIL has shown high potency and specificity for killing cancer cells in preclinical studies, it has failed in multiple clinical trials for several reasons, including a very short half-life mainly caused by instability of the monomeric form of TRAIL and rapid renal clearance of the off-targeted TRAIL. To overcome such obstacles, we developed a TRAIL-active trimer nanocage (TRAIL-ATNC) that presents the TRAIL ligand in its trimer-like conformation by connecting it to a triple helix sequence that links to the threefold axis of the ferritin nanocage. We also ligated the tumor-targeting peptide, IL4rP, to TRAIL-ATNC to enhance tumor targeting. The developed TRAIL-ATNCIL4rP showed enhanced agonistic activity compared with monomeric TRAIL. The in vivo serum half-life of TRAIL-ATNCIL4rP was ~ 16-times longer than that of native TRAIL. As a consequence of these properties, TRAIL-ATNCIL4rP exhibited efficacy as an anti-tumor agent in vivo against xenograft breast cancer as well as orthotopic pancreatic cancer models, highlighting the promise of this system for development as novel therapeutics against cancer.

Surfactant Protein D as a Potential Biomarker and Therapeutic Target in Ovarian Cancer

Surfactant protein D (SP-D) is an important innate immune molecule that is involved in clearing pathogens and regulating inflammation at pulmonary as well as extra-pulmonary sites. Recent studies have established the role of SP-D as an innate immune surveillance molecule against lung and pancreatic cancer, but little is known about its involvement in signaling pathways it can potentially activate in ovarian cancer. We focused our study on ovarian cancer by performing bioinformatics analysis (Oncomine) of datasets and survival analysis (Kaplan-Meier plotter), followed by immunohistochemistry using ovarian cancer tissue microarrays. SP-D mRNA was found to be expressed widely in different types of ovarian cancer irrespective of stage or grade. These in silico data were further validated by immunohistochemistry of clinical tissues. High transcriptional levels of SP-D were associated with unfavorable prognosis (overall and progression-free survival). We also detected SP-D protein in Circulating Tumor Cells of three ovarian cancer patients, suggesting that SP-D can also be used as a potential biomarker. Previous studies have shown that a recombinant fragment of human SP-D (rfhSP-D) induced apoptosis in pancreatic cancer cells via Fas-mediated pathway. In this study, we report that treatment of SKOV3 cells (an ovarian cancer cell line) with rfhSP-D led to a decrease in cell motility and cell proliferation. This was followed by an inhibition of the mTOR pathway activity, increase in caspase 3 cleavage, and induction of pro-apoptotic genes Fas and TNF-α. These data, suggesting a likely protective role of rfhSP-D against ovarian cancer, together with the observation that the ovarian cancer microenvironment overexperesses SP-D leading to poor prognosis, seems to suggest that the tumor microenvironment components manipulate the protective effect of SP-D in vivo.

Structure of the 4-1BB/4-1BBL complex and distinct binding and functional properties of utomilumab and urelumab

4-1BB (CD137, TNFRSF9) is an inducible costimulatory receptor expressed on activated T cells. Clinical trials of two agonist antibodies, utomilumab (PF-05082566) and urelumab (BMS-663513), are ongoing in multiple cancer indications, and both antibodies demonstrate distinct activities in the clinic. To understand these differences, we solved structures of the human 4-1BB/4-1BBL complex, the 4-1BBL trimer alone, and 4-1BB bound to utomilumab or urelumab. The 4-1BB/4-1BBL complex displays a unique interaction between receptor and ligand when compared with other TNF family members. Furthermore, our ligand-only structure differs from previously published data. Utomilumab, a ligand-blocking antibody, binds 4-1BB between CRDs 3 and 4. In contrast, urelumab binds 4-1BB CRD-1, away from the ligand binding site. Finally, cell-based assays demonstrate utomilumab is a milder agonist than urelumab. Collectively, our data provide a deeper understanding of the 4-1BB signaling complex, providing a template for future development of next generation 4-1BB targeted biologics.

The role of XIAP in resistance to TNF-related apoptosis-inducing ligand (TRAIL) in Leukemia

The treatment for leukemic malignancies remains a challenge despite the wide use of conventional chemotherapies. Therefore, new therapeutic approaches are highly demanded. TNF-related apoptosis-inducing ligand (TRAIL) represents a targeted therapy against cancer because it induces apoptosis only in tumor cells. TRAIL is currently under investigation for the treatment of leukemia. Preclinical studies evaluated the potential therapeutic efficacy of TRAIL on cell lines and clinical samples and showed promising results. However, like most anti-cancer drugs, resistance to TRAIL-induced apoptosis may limit its clinical efficacy. It is critical to understand the molecular mechanisms of TRAIL. Therefore, rational therapeutic drug combinations for clinical trials of TRAIL-based therapies might be achieved. In a variety of leukemic cells, overexpression of X-linked inhibitor of apoptosis protein (XIAP), a negative regulator of apoptosis pathway, has been discovered. Implication of XIAP in the ineffective induction of cell death by TRAIL in leukemia has been explored in several resistant cell lines. XIAP inhibitors restored TRAIL sensitivity in resistant cells and primary leukemic blasts. Moreover, TRAIL resistance in leukemic cells could be overcome by the effects of several anti-leukemic agents via the mechanisms of XIAP downregulation. Here, we discuss targeting XIAP, a strategy to restore TRAIL sensitivity in leukemia to acquire more insights into the mechanisms of TRAIL resistance. The concluding remarks may lead to identify putative ways to resensitize tumors.

A versatile platform for activity determination of cytokines and growth factors based on the human TSLP (thymic stromal lymphopoietin) receptor

Cytokines and growth factors are signaling proteins involved in communication processes between cells. They are involved in the control of numerous essential physiological processes such as cell proliferation, gene transcription and differentiation; therefore being in the focus of basic and applied research. Many of them are also of relevance for human diseases. When observed as potential targets for pharmacological intervention and objects of structure/function studies, it is important to measure their biological activities, optionally along with potential inhibitors, in a convenient and rational manner. Such tests are frequently laborious to set up and their establishment is complicated by the necessity to employ problematic cell types and sophisticated assays. Here we present a robust and modular activity assay system which can be adapted to virtually all ligands that signal through dimerization of membrane receptors from different families. The technique rests on fusing ligand-binding domains of specific receptors to the transmembrane and intracellular components of the thymic stromal lymphopoietin (TSLP) receptor which translates signals into readily quantifiable luciferase expression in reporter cells. We show that the activation of various hematopoietic cytokine receptors, of receptor tyrosine kinases as well as of receptors bearing serine/threonine kinase domains by their respective ligands was faithfully reflected both upon transient and stable introduction of hybrid receptor and reporter gene constructs into the murine pro-B cell line Ba/F3. Moreover, we demonstrate the suitability of this platform for the functional characterization of cytokine/growth factor receptor inhibitors.

LST1: A multifunctional gene encoded in the MHC class III region

The LST1 gene is located in the MHC class III cluster between the MHC class I and II regions. While most genes in this cluster have been sufficiently characterised, a definitive function and expression pattern for LST1 still remains elusive. In the present review we describe its promotor, gene organisation, splice variants and expression in human tissues, cell lines and cancer. We focus on LST1 expression in inflammation and discuss known correlations with autoimmune diseases and cancer. Current data on LST1 polymorphisms and their known associations with pathologies are also discussed in detail. We summarize the potential functions that have been described for the full-length LST1 protein including its function as a transmembrane adaptor protein with inhibitory signal transduction and its role as a membrane scaffold facilitating the formation of tunnelling nanotubes. We also discuss further potential functions by compiling all known LST1-interacting proteins. Furthermore, we address knowledge gaps and conflictive issues regarding disease association, non-hematopoietic expression and the discrepancy between RNA and protein expression data.

Host Immunological Effects of Partial Splenic Embolization in Patients with Liver Cirrhosis

Purpose

Restoration of the balance between T lymphocyte subsets and between Th1/Th2 cytokines together with improvement of antitumor immunity has been reported after hepatosplenectomy in patients with liver cirrhosis (LC) and hepatocellular carcinoma (HCC). However, the detailed effects of partial splenic embolization (PSE) on host immunity are unknown. Accordingly, this study evaluated host immunity in patients with cirrhosis receiving PSE for thrombocytopenia.

Methods

Twenty-three adult Japanese patients with cirrhosis and thrombocytopenia underwent PSE using straight coils at our hospital between 2010 and 2015. Blood samples were collected before PSE and 4 weeks after PSE.

Results

The platelet counts were significantly higher 4 weeks after PSE compared with before PSE. The white blood cell count (neutrophils, lymphocytes, and monocytes) also increased significantly after PSE. Furthermore, Th1 cells and Th2 cells showed a significant increase at 4 weeks after PSE compared with before PSE, although there was no significant change of Treg cells. Moreover, serum levels of TNF-alpha, soluble TNF receptor I, and soluble Fas were significantly increased after PSE. There was no significant change of the Child-Pugh score.

Conclusions

In patients with cirrhosis and thrombocytopenia, PSE not only promoted the recovery of leukopenia and thrombocytopenia but also induced activation of host immunity.

A Recombinant Fragment of Human Surfactant Protein D induces Apoptosis in Pancreatic Cancer Cell Lines via Fas-Mediated Pathway

Human surfactant protein D (SP-D) is a potent innate immune molecule, which is emerging as a key molecule in the recognition and clearance of altered and non-self targets. Previous studies have shown that a recombinant fragment of human SP-D (rfhSP-D) induced apoptosis via p53-mediated apoptosis pathway in an eosinophilic leukemic cell line, AML14.3D10. Here, we report the ability of rfhSP-D to induce apoptosis via TNF-α/Fas-mediated pathway regardless of the p53 status in human pancreatic adenocarcinoma using Panc-1 (p53mt), MiaPaCa-2 (p53mt), and Capan-2 (p53wt) cell lines. Treatment of these cell lines with rfhSP-D for 24 h caused growth arrest in G1 cell cycle phase and triggered transcriptional upregulation of pro-apoptotic factors such as TNF-α and NF-κB. Translocation of NF-κB from the cytoplasm into the nucleus of pancreatic cancer cell lines was observed via immunofluorescence microscopy following treatment with rfhSP-D as compared to the untreated cells. The rfhSP-D treatment caused upregulation of pro-apoptotic marker Fas, as analyzed via qPCR and western blot, which then triggered caspase cascade, as evident from cleavage of caspase 8 and 3 analyzed via western blot at 48 h. The cell number following the rfhSP-D treatment was reduced in the order of Panc-1 (~67%) > MiaPaCa-2 (~60%) > Capan-2 (~35%). This study appears to suggest that rfhSP-D can potentially be used to therapeutically target pancreatic cancer cells irrespective of their p53 phenotype.

Quinic acid inhibits vascular inflammation in TNF-α-stimulated vascular smooth muscle cells

Atherosclerosis is a chronic inflammatory disease, and the increased expression of adhesion molecules on vascular smooth muscle cells contributes to the progression of vascular disease. Quinic acid (QA) has been shown to possess radioprotection, anti-neuroinflammatory, and anti-oxidant activities; however, an anti-vascular inflammatory effect has not been reported. This study investigated the effect of QA on the expression of vascular cell adhesion molecule-1 (VCAM-1) stimulated by TNF-α in MOVAS cells. Pre-incubation of MOVAS cells, the mouse vascular smooth muscle cell line for 2h with QA (0.1, 1 and 10 μg/mL) dose-dependently inhibits TNF-α-induced mRNA and protein expression of VCAM-1 and monocyte adhesion. QA inhibits TNF-α-stimulated phosphorylation of MAP kinase and NK-κB activation. Our results indicate that QA inhibits the TNF-α-stimulated induction of VCAM-1 in VSMC by inhibiting the MAP kinase and NF-κB signaling pathways and the adhesion capacity of VSMC, which may explain the ability of QA to inhibit vascular inflammation such as atherosclerosis.

Enhanced immune-modulatory effects of thalidomide and dexamethasone co-treatment on T cell subsets

Thalidomide (TM) has been reported to have anti-cancer and anti-inflammatory properties, and dexamethasone (DX) is known to reduce inflammation and inhibit production of inflammatory cytokines. Many studies have reported that combinatorial therapy with TM and DX is clinically used to treat multiple myeloma and lupus nephritis, but the mechanism responsible for its effects has not been elucidated. In this study, we determined that TM and DX co-treatment had an enhanced immune-modulatory effect on T cells through regulating the expression of co-stimulatory molecules. Splenic naive T cells from C57BL/6 mice were sort-purified and cultured for CD4⁺ T cell proliferation and regulatory T (Treg) cell conversion in the presence of TM and/or DX. Following incubation with the drugs, cells were collected and OX40, 4-1BB, and glucocorticoid-induced tumour necrosis factor receptor-related protein (GITR) expression was quantified by flow cytometry. TM (1 or 10 μm) decreased CD4⁺ T cell proliferation in a dose-dependent manner, whereas TM/DX (0·1 or 1 nm) co-treatment further decreased proliferation. Treg cell populations were preserved following drug treatment. Furthermore, expression of co-stimulatory molecules decreased upon TM/DX co-treatment in effector T (Teff) cells and was preserved in Treg cells. Splenic CD4⁺ T cells isolated from TM- and DX-treated mice exhibited the same patterns of Teff and Treg cell populations as observed in vitro. Considering the selective effect of TM on different T cell subsets, we suggest that TM may play an immunomodulatory role and that TM/DX combinatorial treatment could further enhance these immunomodulatory effects by regulating GITR, OX40, and 4-1BB expression in CD4⁺ T cells.

TRAIL-NP hybrids for cancer therapy: a review

Cancer is a worldwide health problem. It is now considered as a leading cause of morbidity and mortality in developed countries. In the last few decades, considerable progress has been made in anti-cancer therapies, allowing the cure of patients suffering from this disease, or at least helping to prolong their lives. Several cancers, such as those of the lung and pancreas, are still devastating in the absence of therapeutic options. In the early 90s, TRAIL (Tumor Necrosis Factor-related apoptosis-inducing ligand), a cytokine belonging to the TNF superfamily, attracted major interest in oncology owing to its selective anti-tumor properties. Clinical trials using soluble TRAIL or antibodies targeting the two main agonist receptors (TRAIL-R1 and TRAIL-R2) have, however, failed to demonstrate their efficacy in the clinic. TRAIL is expressed on the surface of natural killer or CD8+ T activated cells and contributes to tumor surveillance. Nanoparticles functionalized with TRAIL mimic membrane-TRAIL and exhibit stronger antitumoral properties than soluble TRAIL or TRAIL receptor agonist antibodies. This review provides an update on the association and the use of nanoparticles associated with TRAIL for cancer therapy.

Lobaric Acid Inhibits VCAM-1 Expression in TNF-α-Stimulated Vascular Smooth Muscle Cells via Modulation of NF-κB and MAPK Signaling Pathways

Lichens have been known to possess multiple biological activities, including anti-proliferative and anti-inflammatory activities. Vascular cell adhesion molecule-1 (VCAM-1) may play a role in the development of atherosclerosis. Hence, VCAM-1 is a possible therapeutic target in the treatment of the inflammatory disease. However, the effect of lobaric acid on VCAM-1 has not yet been investigated and characterized. For this study, we examined the effect of lobaric acid on the inhibition of VCAM-1 in tumor necrosis factor-alpha (TNF-α)-stimulated mouse vascular smooth muscle cells. Western blot and ELISA showed that the increased expression of VCAM-1 by TNF-α was significantly suppressed by the pre-treatment of lobaric acid (0.1–10 μg/ml) for 2 h. Lobaric acid abrogated TNF-α-induced NF-κB activity through preventing the degradation of IκB and phosphorylation of extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinases (JNK), and p38 mitogen activated protein (MAP) kinase. Lobaric acid also inhibited the expression of TNF-α receptor 1 (TNF-R1). Overall, our results suggest that lobaric acid inhibited VCAM-1 expression through the inhibition of p38, ERK, JNK and NF-κB signaling pathways, and downregulation of TNF-R1 expression. Therefore, it is implicated that lobaric acid may suppress inflammation by altering the physiology of the atherosclerotic lesion.

The development of immunomodulatory monoclonal antibodies as a new therapeutic modality for cancer: the Bristol-Myers Squibb experience

The discovery and increased understanding of the complex interactions regulating the immune system have contributed to the pharmacologic activation of antitumor immunity. The activity of effector cells, such as T and NK cells, is regulated by an array of activating and attenuating receptors and ligands. Agents that target these molecules can modulate immune responses by exerting antagonistic or agonistic effects. Several T- or NK-cell modulators have entered clinical trials, and two have been approved for use. Ipilimumab (Yervoy®, Bristol-Myers Squibb) and nivolumab (OPDIVO, Ono Pharmaceutical Co., Ltd./Bristol-Myers Squibb) were approved for the treatment of metastatic melanoma, in March 2011 in the United States, and in July 2014 in Japan, respectively. The clinical activity of these two antibodies has not been limited to tumor types considered sensitive to immunotherapy, and promising activity has been reported in other solid and hematologic tumors. Clinical development of ipilimumab and nivolumab has presented unique challenges in terms of safety and efficacy, requiring the establishment of new evaluation criteria for adverse events and antitumor effects. Guidelines intended to help oncologists properly manage treatment in view of these non-traditional features have been implemented. The introduction of this new modality of cancer treatment, which is meant to integrate with or replace the current standards of care, requires additional efforts in terms of optimization of treatment administration, identification of biomarkers and application of new clinical trial designs. The availability of immune modulators with different mechanisms of action offers the opportunity to establish immunological combinations as new standards of care.

Osteoprotegerin and kidney disease

Vascular calcification in chronic kidney disease (CKD) patients is associated to increased mortality. Osteoprotegerin (OPG) is a soluble tumor necrosis factor (TNF) superfamily receptor that inhibits the actions of the cytokines receptor activator of nuclear factor kappa-B ligand (RANKL) and TNF-related apoptosis-inducing ligand (TRAIL) by preventing their binding to signaling receptors in the cell membrane. OPG-deficient mice display vascular calcification while OPG prevented calcification of cultured vascular smooth muscle cells and protected kidney cells from TRAIL-induced death. OPG may be a biomarker in patients with kidney disease. Circulating OPG is increased in predialysis, dialysis and transplant CKD patients and may predict vascular calcification progression and patient survival. By contrast, circulating OPG is decreased in nephrotic syndrome. In addition, free and exosome-bound urinary OPG is increased in human kidney disease. Increased urinary OPG has been associated with lupus nephritis activity. Despite the association of high OPG levels with disease, experimental functional information available suggests that OPG might be protective in kidney disease and in vascular injury in the context of uremia. Thus, tissue injury results in increased OPG, while OPG may protect from tissue injury. Recombinant OPG was safe in phase I randomized controlled trials. Further research is needed to fully define the therapeutic and biomarker potential of OPG in patients with kidney disease.

Changes of cytokines in patients with liver cirrhosis and advanced hepatocellular carcinoma treated by sorafenib

PURPOSE

Recently, the oral multikinase inhibitor sorafenib has been used to treat advanced hepatocellular carcinoma (aHCC). Tumor necrosis factor (TNF) induces apoptosis of tumor cells by binding to TNF-related apoptosis-inducing ligand, while binding of the Fas ligand on cytotoxic T lymphocytes to the Fas receptor on hepatocytes also causes apoptosis. The aim of this study was to retrospectively evaluate changes of cytokines in patients with liver cirrhosis (LC) and aHCC receiving sorafenib therapy.

METHODS

Fifty-seven adult Japanese LC patients received sorafenib for aHCC (200-800 mg/day for 4 weeks) between 2009 and 2012 at our hospital. Blood samples were collected in the early morning before and after treatment, and the serum levels of soluble TNF-alpha (sTNF-alpha), soluble TNF receptor (sTNF-R), soluble Fas ligand (sFas L), and soluble Fas (sFas) were evaluated.

RESULTS

Ten patients were treated with sorafenib at 200 mg/day (200 mg group), 37 patients were given 400 mg/day (400 mg group), and 10 patients received 800 mg/day (800 mg group). The serum level of sTNF-alpha was significantly increased after treatment compared with before treatment in the 400 and 800 mg groups. The serum level of sTNF-R also showed a significant increase after treatment in the 400 mg group, although there was no significant difference of sTNF-R between before and after treatment in the 200 and 800 mg groups. sFas showed a significant decrease after treatment compared with before treatment in the 400 and 800 mg groups, although the serum level of sFas L never exceeded 0.15 ng/ml.

CONCLUSIONS

These findings suggest that treatment with sorafenib at doses ≥400 mg/day might promote TNF-related or Fas-related apoptosis by increasing the circulating level of TNF-alpha or decreasing that of sFas.

Down-regulation of Fas-mediated apoptosis by plasma transglutaminase factor XIII that catalyzes fetal-specific cross-link of the Fas molecule

The Fas antigen, also designated as APO-1 or CD95, is a member of the tumor necrosis factor receptor superfamily and can mediate apoptotic cell death in various cells. We report here that blood coagulation factor XIII (plasma transglutaminase, fibrin stabilizing factor) inhibits apoptosis induced by a cytotoxic anti-Fas monoclonal antibody in Jurkat cells. When cells were treated with the antibody in fetal calf serum-containing media, higher-molecular-weight (180K) polypeptides containing Fas molecule were detected by immunoblotting. Under conditions where the transglutaminase activity was eliminated or suppressed, the cross-link of Fas was not observed, and concurrently cell death was hastened. Moreover, an antibody against factor XIII strongly accelerated the Fas-mediated apoptosis. Furthermore, addition of partially purified factor XIII neutralized the apoptosis-promoting effect of anti-factor XIII antibody, indicating that this enzyme is involved in cross-link of Fas and down-regulates Fas-mediated apoptotic cell death. Significantly, the cross-link of Fas was seen only in fetal calf serum but not in newly-born calf serum, 1-year-old calf serum or adult bovine serum. These data suggest that plasma transglutaminase factor XIII may play a key role in fetal development of vertebrates via cross-link of Fas antigen.

Strategies for immunophenotyping and purifying classical Hodgkin lymphoma cells from lymph nodes by flow cytometry and flow cytometric cell sorting

Flow cytometry is an established technique to immunophenotype hematopoietic neoplasms. While the diagnosis of classical Hodgkin lymphoma (CHL) has commonly been made using paraffin sections, we have recently demonstrated that the neoplastic Hodgkin and Reed-Sternberg (HRS) cells of CHL can be identified by flow cytometry. Using 6- and 9-color flow cytometric assays, CHL can be immunophenotyped with 85-90% sensitivity and nearly 100% specificity. Analysis of this data requires using established gating strategies to help in the identification of putative HRS cell populations. Interestingly, HRS cells bind to reactive T cells (HRS-T cell rosetting) and this phenomenon can be identified and utilized diagnostically by flow cytometry. In addition, the reactive T cells of CHL show characteristic immunophenotypic changes by flow cytometry and these changes can suggest a diagnosis of CHL. Finally, these principles can be employed to rapidly purify HRS cells using flow cytometric cell sorting. This manuscript provides experimental protocols for immunophenotyping CHL by flow cytometry as well as purifying the HRS cells via flow cytometric cell sorting.

Sensitization of human bladder tumor cells to TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis with a small molecule IAP antagonist

Urothelial carcinoma of the bladder accounts for approximately 5% of all cancer deaths in humans. The large majority of bladder tumors are non-muscle invasive at diagnosis, but even after local surgical therapy there is a high rate of local tumor recurrence and progression. Current treatments extend time to recurrence but do not significantly alter disease survival. The objective of the present study was to investigate the tumoricidal potential of combining the apoptosis-inducing protein TNF-related apoptosis-inducing ligand (TRAIL) with a small molecule inhibitor of apoptosis proteins (IAP) antagonist to interfere with intracellular regulators of apoptosis in human bladder tumor cells. Our results demonstrate that the IAP antagonist Compound A exhibits high binding affinity to the XIAP BIR3 domain. When Compound A was used at nontoxic concentrations in combination with TRAIL, there was a significant increase in the sensitivity of TRAIL-sensitive and TRAIL-resistant bladder tumor lines to TRAIL-mediated apoptosis. In addition, modulation of TRAIL sensitivity in the TRAIL-resistant bladder tumor cell line T24 with Compound A was reciprocated by XIAP small interfering RNA-mediated suppression of XIAP expression, suggesting the importance of XIAP-mediated resistance to TRAIL in these cells. These results suggest the potential of combining Compound A with TRAIL as an alternative therapy for bladder cancer.

Aberrant expression of CD30 in neoplastic mast cells in high-grade mastocytosis

Systemic mastocytosis either presents as aggressive neoplasm with short survival time or indolent systemic mastocytosis with normal life expectancy. In both instances, neoplastic mast cells usually harbor the D816V-mutated variant of KIT. Phenotypically, mast cells in systemic mastocytosis usually express CD25. However, no robust marker that discriminates between aggressive and indolent variants of systemic mastocytosis has been identified yet. We here report that CD30, also known as Ki-1 antigen, is expressed in neoplastic mast cells in a majority of patients with advanced systemic mastocytosis (11/13, 85%), whereas in most patients with indolent systemic mastocytosis (12/45, 27%; P<0.001), only a few if any mast cells stained positive for CD30. These results could be confirmed by TissueFAXS analysis in subsets of patients with indolent systemic mastocytosis (n=7) and advanced systemic mastocytosis (n=4; P=0.008). The mast cell leukemia cell line HMC-1, derived from a patient with aggressive systemic mastocytosis also expressed the CD30 protein. In addition, we were able to detect CD30 mRNA in HMC-1 cells as well as in bone marrow biopsy samples in patients with systemic mastocytosis. In contrast, CD30 transcripts could not be detected in bone marrow biopsies in cases of reactive mast cell hyperplasia and in various other myeloid neoplasms. In conclusion, CD30 is preferentially expressed in neoplastic mast cells in advanced mast cell neoplasms. Upregulated expression of CD30 in advanced systemic mastocytosis may thus be employed as a potential marker for grading systemic mastocytosis in hematopathology.

Molecular identification and expression analysis of a novel tumor necrosis factor receptor from the black rockfish, Sebastes schlegelii

Members of the tumor necrosis factor (TNF) and TNF receptor (TNFR) superfamilies play crucial roles in both innate and adaptive immunity. In the present study, we isolated the full-length cDNA for black rockfish (Sebastes schlegelii) TNFR (BrTNFR). This cDNA is 2405 bp in length and contains a 939-bp open reading frame, a 27-bp 5' untranslated region, and a 1439-bp 3' untranslated region including a polyadenylation signal (AATAAA) and polyadenylation site. The 313-amino-acid predicted BrTNFR sequence is homologous to other TNFR sequences, contains four cysteine-rich domains and a death-effector domain (DED), and lacks a transmembrane region. Expression of BrTNFR mRNA was detected in eight different tissues from healthy black rockfish and was highest in peripheral blood lymphocytes and gills. In analyses of mitogen-stimulated BrTNFR expression in peripheral blood lymphocytes, expression of BrTNFR mRNA was observed between 1 and 24h after stimulation with lipopolysaccharide, concanavalin A/phorbol myristate acetate, or poly I:C. Although the data suggest that BrTNFR represents an ancestral member of the TNFR superfamily, the orthology of TNFR in teleost fish is difficult to establish because few TNFRs have been identified in these species.

Macrophages express membrane bound form of APRIL that can generate immunomodulatory signals

Members of the tumour necrosis factor superfamily play an essential role in inducing various biological responses including proliferation, differentiation, survival and cell death. A proliferation-inducing ligand (APRIL), first identified as a stimulant of tumour proliferation, is now known as a regulator of B-cell-mediated immune responses through the modulation of B-cell survival and activation. However, the role of APRIL in macrophage function has not been explored. High level expression of APRIL was detected on the surface of cells of the monocytic lineage including the human macrophage-like cell line, THP-1. To identify the role of APRIL in macrophage functions, THP-1 cells were stimulated with either its counterpart (TACI : Fc fusion protein) or a monoclonal antibody that is specific to APRIL. Stimulation of APRIL resulted in the expression of pro-inflammatory mediators such as interleukin-8 and matrix metalloproteinase-9 through the activation of mitogen-activated protein kinase and nuclear factor-κB. In contrast, stimulation of APRIL had an inhibitory effect on processes that require cytoskeletal movement such as phagocytosis of opsonized zymosan and chemotaxis through an inhibition of phosphatidylinositol 3-kinase activity. These observations demonstrate that macrophages express a membrane-bound form of APRIL which, upon stimulation, modulates the activities of macrophages through stimulation or inhibition of processes associated with inflammation.

Aberrant expression of CD30 in aggressive systemic mastocytosis and mast cell leukemia: a differential diagnosis to consider in aggressive hematopoietic CD30-positive neoplasms

During the past two decades the immunophenotype of normal, reactive, and neoplastic mast cells (MCs) has been established. These studies have convincingly demonstrated that MCs form a separate lineage within the myeloid cell family. A most intriguing finding was that in contrast to normal MCs, neoplastic MCs in systemic mastocytosis (SM) aberrantly express several lymphoid marker antigens such as CD2 and CD25. This phenomenon has now been topped by the unexpected observation that neoplastic MCs in aggressive variants of SM and MC leukemia (leukemic variant of SM) aberrantly express CD30, whereas this antigen, Ki-1, is not detectable or is expressed only weakly in MCs in most patients with indolent SM. These observations may have implications for the evolution of SM as well as for diagnostic evaluation and grading in these patients. Moreover, these observations suggest that advanced SM has to be considered as a differential diagnosis of CD30-positive lymphoid neoplasms. Finally, CD30 may be considered as a potential target of antibody-based therapeutic intervention in advanced mast cell disorders.

TNF superfamily: a growing saga of kidney injury modulators

Members of the TNF superfamily participate in kidney disease. Tumor necrosis factor (TNF) and Fas ligand regulate renal cell survival and inflammation, and therapeutic targeting improves the outcome of experimental renal injury. TNF-related apoptosis-inducing ligand (TRAIL and its potential decoy receptor osteoprotegerin are the two most upregulated death-related genes in human diabetic nephropathy. TRAIL activates NF-kappaB in tubular cells and promotes apoptosis in tubular cells and podocytes, especially in a high-glucose environment. By contrast, osteoprotegerin plays a protective role against TRAIL-induced apoptosis. Another family member, TNF-like weak inducer of apoptosis (TWEAK induces inflammation and tubular cell death or proliferation, depending on the microenvironment. While TNF only activates canonical NF-kappaB signaling, TWEAK promotes both canonical and noncanonical NF-kappaB activation in tubular cells, regulating different inflammatory responses. TWEAK promotes the secretion of MCP-1 and RANTES through NF-kappaB RelA-containing complexes and upregulates CCl21 and CCL19 expression through NF-kappaB inducing kinase (NIK-) dependent RelB/NF-kappaB2 complexes. In vivo TWEAK promotes postnephrectomy compensatory renal cell proliferation in a noninflammatory milieu. However, in the inflammatory milieu of acute kidney injury, TWEAK promotes tubular cell death and inflammation. Therapeutic targeting of TNF superfamily cytokines, including multipronged approaches targeting several cytokines should be further explored.

The structure of the trimer of human 4-1BB ligand is unique among members of the tumor necrosis factor superfamily

Binding of the 4-1BB ligand (4-1BBL) to its receptor, 4-1BB, provides the T lymphocyte with co-stimulatory signals for survival, proliferation, and differentiation. Importantly, the 4-1BB-4-1BBL pathway is a well known target for anti-cancer immunotherapy. Here we present the 2.3-A crystal structure of the extracellular domain of human 4-1BBL. The ectodomain forms a homotrimer with an extended, three-bladed propeller structure that differs from trimers formed by other members of the tumor necrosis factor (TNF) superfamily. Based on the 4-1BBL structure, we modeled its complex with 4-1BB, which was consistent with images obtained by electron microscopy, and verified the binding site by site-directed mutagenesis. This structural information will facilitate the development of immunotherapeutics targeting 4-1BB.

Tumor-targeted delivery of biologically active TRAIL protein

The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a potent inducer of tumor cell apoptosis, but concerns of considerable liver toxicity limit its uses in human cancer therapy. Here, we show that i.v. injected Escherichia coli DH5α (E. coli DH5α) specifically replicates in solid tumors and metastases in live animals. E. coli DH5α does not enter tumor cells and suits for being the vector for soluble TRAIL (sTRAIL), which induces apoptosis by activating cell-surface death receptors. With the high ‘tumor-targeting' nature, we demonstrate that intratumoral (i.t.) and intravenous injection of sTRAIL-expressing E. coli DH5α results in the tumor-targeted release of biologically active molecules, which leads to a dramatic reduction in the tumor growth rate and the prolonged survival of tumor-bearing mice. TRAIL delivery by E. coli DH5α did not cause any detectable toxicity to any organs, suggesting that E. coli DH5α-delivered sTRAIL protein therapy may provide a feasible and effective form of treatment for solid tumors.

CD137 agonist antibody prevents cancer recurrence: contribution of CD137 on both hematopoietic and nonhematopoietic cells

Antigen-specific memory T cells (Tms) are essential in the immune surveillance of residual and metastatic tumors. Activation of Tms requires designing vaccines based on tumor rejection antigens, which are often not available to cancer patients. Therefore, it is desirable to have a general applicable approach to activate Tms without extensive knowledge of tumor antigens. Here, we report that activation of antigen-specific Tms could be achieved by the administration of agonistic anti-CD137 monoclonal antibody without additional tumor vaccination, leading to the prevention of recurrence and metastases after surgical resection of primary tumors in mouse models. By reconstitution with CD137-deficient Tms, we demonstrate that expression of CD137 on antigen-specific Tms is only partially required for the effect of anti-CD137 antibody. Other host cells, including those from hematopoietic and nonhematopoietic origins, are also important because ablation of CD137 from these cells partially but significantly eliminates antitumor effect of anti-CD137 antibody. Our findings implicate a potential new approach to prevent recurrence and metastases in cancer patients.

TNF-related apoptosis-inducing ligand (TRAIL): a new path to anti-cancer therapies

Since its discovery in 1995, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a member of the tumor necrosis factor super family, has been under intense focus because of its remarkable ability to induce apoptosis in malignant human cells while leaving normal cells unscathed. Consequently, activation of the apoptotic signaling pathway from the death-inducing TRAIL receptors provides an attractive, biologically-targeted approach to cancer therapy. A great deal of research has focused on deciphering the TRAIL receptor signaling cascade and intracellular regulation of this pathway, as many human tumor cells possess mechanisms of resistance to TRAIL-induced apoptosis. This review focuses on the current state of knowledge regarding TRAIL signaling and resistance, the preclinical development of therapies targeted at TRAIL receptors and modulators of the pathway, and the results of clinical trials for cancer treatment that have emerged from this base of knowledge. TRAIL-based approaches to cancer therapy vary from systemic administration of recombinant, soluble TRAIL protein with or without the combination of traditional chemotherapy, radiation or novel anti-cancer agents to agonistic monoclonal antibodies directed against functional TRAIL receptors to TRAIL gene transfer therapy. A better understanding of TRAIL resistance mechanisms may allow for the development of more effective therapies that exploit this cell-mediated pathway to apoptosis.

TNFR signaling: ubiquitin-conjugated TRAFfic signals control stop-and-go for MAPK signaling complexes

Nearly two decades after the initial cloning and identification of the founding father of the tumor necrosis factor receptor (TNFR) family, much has been learned about the mechanisms by which these receptors signal to critical transcription factors and other targets that regulate gene expression and cellular physiology. Mitogen-activated protein kinases (MAPKs) and inhibitor of nuclear factor (NF)-kappaB (I kappaB) kinases (IKKs) were identified early on as the upstream kinases responsible for activation of activator-protein 1 (AP-1) and NF-kappaB, respectively, and later on for their ability to control life-or-death decisions in TNF-stimulated cells. Both of these critical pathways are regulated at the level of MAPK kinase kinases (MAP3Ks), after which point they diverge. Recent work, however, illustrates that protein ubiquitination cascades play a critical initiating role in TNFR signaling and account for spatial and temporal separation of IKK and MAPK signaling cascades and thereby determine biological specificity and outcome. Cellular inhibitors of apoptosis (cIAPs) 1 and 2 are ubiquitin (Ub) ligases (E3s) that mediate canonical Lys48-linked ubiquitination of TNFR-associated factor 3 (TRAF3), marking it for subsequent degradation by the proteasome. TRAF3 degradation releases the brake on TRAF2/6:MAP3K signaling complexes responsible for MAPK activation, leading to their translocation from the cytoplasmic segment of the receptor to the cytosol where they initiate MAPK phosphorylation and activation. By contrast, IKK activation proceeds considerably faster than MAPK activation, takes place at the receptor, and is independent of cIAP1/2 activity and TRAF3 degradation. This arrangement may be important for ensuring the proper delivery of NF-kappaB-dependent survival signals and conversion of JNK-promoted death signals to proliferative ones.

Memory T cells need CD28 costimulation to remember

The activation and expansion of naïve T cells require costimulatory signals provided by CD28 and TNF family members. In contrast, for many years it was believed that memory T cells do not require CD28 costimulation for expansion during secondary responses. This was based on in vitro experiments that suggested the re-activation of memory T cells is somewhat independent of costimulation. Recent in vivo evidence, however, has challenged this and shown that both CD4+ and CD8+ memory T cells require CD28 costimulation for maximal expansion and pathogen clearance. This requirement has important implications for host immunity, vaccine development and immunotherapeutics.

The promise of 4-1BB (CD137)-mediated immunomodulation and the immunotherapy of cancer

The continuing efforts in biomedical research to develop new therapies for cancer are entering an exciting new phase. Research over the past two to three decades has yielded a much more detailed understanding of the complexities of the cellular and molecular interactions involved in the generation and regulation of immune responses. We are also gaining insights into the mechanisms by which tumors evade or escape immune recognition and by which they become resistant to various existing chemotherapeutic and/or radiotherapeutic strategies. A clear conclusion that can be drawn from these studies is that effective treatments of cancer will become much more multifaceted and will include immunotherapeutic approaches. The identification and molecular cloning of genes encoding the receptors and ligands that play crucial roles in the generation and regulation of immune responses provides exciting new opportunities to induce and enhance effective endogenous immune responses to cancer. In this regard, the genes that comprise the tumor necrosis factor and tumor necrosis factor receptor superfamilies show particular promise. One receptor:ligand pair (4-1BB/CD137 and 4-1BBL/CD137L) is emerging as a target with important potential in its ability to enhance the generation of effective tumor-specific immune responses in situ. The results of the studies cited in this review highlight the potentials of 4-1BB-mediated immunotherapy.

OX40 (CD134) and OX40L

The interaction between OX40 and OX40L plays an important role in antigen-specific T-cell expansion and survival. While OX40 is expressed predominantly on T-lymphocytes early after antigen activation, OX40L is expressed on activated antigen presenting cells and endothelial cells within acute inflammatory environments. We discuss here how ligation of OX40 by OX40L leads to enhanced T-cell survival, along with local inflammatory responses that appear critical for both effective T-cell mediated responses and chronic immune pathologies. We describe how interventions that block or mimic the OX40-OX40L interaction can be applied to treat autoimmune diseases or enhance anti-tumor immune responses. The clinically relevant properties of these agents emphasize the importance of this particular TNFSF-TNFSF in health and disease.

Chimeric form of tumor necrosis factor-alpha has enhanced surface expression and antitumor activity

Tumor necrosis factor (TNF)-alpha is a type-II transmembrane protein that is cleaved by TNF-alpha-converting enzyme (TACE/ADAM-17) to release soluble TNF, a cytokine with potent antitumor properties whose use in clinical applications is limited by its severe systemic toxicity. We found that human cells transfected with vectors encoding TNF without the TACE cleavage site (DeltaTACE-TNF) still released functional cytokine at substantial levels that varied between transfected cell lines of different tissue types. Vectors encoding membrane-associated domains of CD154, another TNF-family protein, conjoined with the carboxyl-terminal domain of TNF, directed higher-level surface expression of a functional TNF that, in contrast to DeltaTACE-TNF, was resistant to cleavage in all cell types. Furthermore, adenovirus vectors encoding CD154-TNF had significantly greater in vivo biological activity in inducing regression of established, syngeneic tumors in mice than adenovirus vectors encoding TNF, and lacked toxicity associated with soluble TNF. As such, CD154-TNF is a novel TNF that appears superior for treatment of tumors in which high-level local expression of TNF is desired.

Molecular cloning and preliminary expression analysis of banded dogfish (Triakis scyllia) TNF decoy receptor 3 (TNFRSF6B)

Decoy receptor 3 (DcR3), a member of TNF receptor superfamily, is a soluble receptor without death domain and cytoplasmic domain, and secreted by cells and binds with FasL, LIGHT and TL1A. The principal function of DcR3 is the inhibition of apoptosis by the binding cytotoxic ligands. Expression of DcR3 has been reported in a wide array of normal human tissues as well as tumors and tumor cell lines. Recently, DcR3 was reported to modulate a variety of immune responses in mammals. TNFR or DcR3 has been identified in some teleost fishes. However, DcR3 is not reported in cartilaginous fish which is the lowest vertebrate possessing the adaptive immune system. Here we identified DcR3 cDNA in shark (Trsc-DcR3) from an SSH library prepared from peripheral white blood cells stimulated with PMA. Four cysteine-rich domains (CRDs) in common with TNF receptor family members are present in the Trsc-DcR3 sequence. The deduced amino acid sequence of Trsc-DcR3 showed highest identity with the chicken (50.4%), followed by human (46.8%) and rainbow trout (36.5%) DcR3. In a phylogenetic tree of known TNFRSF sequences, the Trsc-DcR3 grouped with the chicken and human DcR3. Trsc-DcR3 mRNA was detected strongly in the gill, moderately in the brain, and weakly in the kidney, thymus and leydig. These data strongly suggest that the gene encoding Trsc-DcR3 in banded dogfish is a homolog of the human gene. mRNA expression of Trsc-DcR3 in the thymus and leydig suggests that DcR3 may act as a modulator in the immune system even at the phylogenetic level of cartilaginous fish.

Biomarkers of HIV related central nervous system disease

In this review we critically assess biomarkers of the direct effects of HIV related brain disease. This area is becoming increasingly complex because of the presence of confounds and varying degrees of activity of HIV brain disease. Sensitive and specific biomarkers are urgently needed although existing biomarkers do have some utility. The review will focus on the practical implications of the more established biomarkers. We discuss blood, cerebrospinal fluid and neurophysiological biomarkers but not neuroimaging techniques as they are beyond the scope of this review.