Intervertebral disc degeneration proceeds with age and is one of the major causes of lumbar pain and degenerative lumbar spine diseases. However, studies in the field of intervertebral disc biology have been hampered by the lack of reliable cell lines that can be used for in vitro assays. In this study, we show that a chordoma‐derived cell line U‐CH1‐N cells highly express the nucleus pulposus (NP) marker genes, including T (encodes T brachyury transcription factor), KRT19, and CD24. These observations were further confirmed by immunocytochemistry and flow cytometry. Reporter analyses showed that transcriptional activity of T was enhanced in U‐CH1‐N cells. Chondrogenic capacity of U‐CH1‐N cells was verified by evaluating the expression of extracellular matrix (ECM) genes and Alcian blue staining. Of note, we found that proliferation and synthesis of chondrogenic ECM proteins were largely dependent on T in U‐CH1‐N cells. In accordance, knockdown of the T transcripts suppressed the expression of PCNA, a gene essential for DNA replication, and SOX5 and SOX6, the master regulators of chondrogenesis. On the other hand, the CD24‐silenced cells showed no reduction in the mRNA expression level of the chondrogenic ECM genes. These results suggest that U‐CH1‐N shares important biological properties with notochordal NP cells and that T plays crucial roles in maintaining the notochordal NP cell‐like phenotype in this cell line. Taken together, our data indicate that U‐CH1‐N may serve as a useful tool in studying the biology of intervertebral disc. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 34:1341–1350, 2016.
nucleus pulposus cell; notochord; chordoma; U‐CH1‐N
Background and study aims: Several meta-analyses and randomized control trials have demonstrated the efficacy of rectal nonsteroidal anti-inflammatory drugs for preventing post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). Diclofenac or indomethacin was administered at a dose of 100 mg in those studies, which may be too high for Asian population. In addition, rectal administration can be considered complicated.
Patients and methods: This study was a prospective, randomized, placebo-controlled trial. Patients with a PEP risk score ≥ 1 were randomly assigned to receive intravenous injection of 50 mg flurbiprofen axetil (flurbiprofen group) or saline only (placebo group). The primary outcome was reduced PEP. The secondary outcome was amylase level after 2 hours of ERCP as a predictor of PEP. (Clinical Trials.gov, ID UMIN000011322)
Results: In total, 144 patients were enrolled from August 2013 to March 2015. We performed an interim analysis of the first 100 patients: 47 received flurbiprofen axetil and 53 received placebo. PEP occurred in 11 patients (11 %): 2 of 47 (4.3 %) in the flurbiprofen group and 9 of 53 (17 %) in the placebo group (P = 0.042). Relative risk reduction was 62.4 %. Hyperamylasemia did not differ significantly (17.0 % vs. 26.4 %, P = 0.109). This analysis resulted in early termination of the study for ethical reasons.
Conclusions: Intravenous injection of low-dose flurbiprofen axetil after ERCP can reduce the incidence of PEP in high-risk patients
Whether Propionibacterium acnes (P. acnes) causes surgical-site infections (SSI) after orthopedic surgery is controversial. We previously reported that we frequently find P. acnes in intraoperative specimens, yet none of the patients have clinically apparent infections. Here, we tracked P. acnes for 6 months in a mouse osteomyelitis model. We inoculated P. acnes with an implant into the mouse femur in the implant group; the control group was treated with the bacteria but no implant. We then observed over a 6-month period using optical imaging system. During the first 2 weeks, bacterial signals were detected in the femur in the both groups. The bacterial signal completely disappeared in the control group within 28 days. Interestingly, in the implant group, bacterial signals were still present 6 months after inoculation. Histological and scanning electron-microscope analyses confirmed that P. acnes was absent from the control group 6 months after inoculation, but in the implant group, the bacteria had survived in a biofilm around the implant. PCR analysis also identified P. acnes in the purulent effusion from the infected femurs in the implant group. To our knowledge, this is the first report showing that P. acnes causes SSI only in the presence of an implant.
Recent evidence suggest that a β-glucan derived from mushroom Schizophyllan(SPG) complexed with a humanized TLR9 agonistic CpG DNA, K3 (K3-SPG) is a promising vaccine adjuvant that induces robust CD8 T cell responses to co-administered antigen. However, it has not been investigated whether K3-SPG alone can act as an anti-cancer immunotherapeutic agent or not. Here, we demonstrate that intravenous injection of K3-SPG, but not CpG alone, is accumulated in the tumor microenvironment and triggered immunogenic cell death (ICD) of tumor cells by local induction of type-I interferon (IFN) as well as IL-12. Resultant innate immune activation as well as subsequent tumor-specific CD8 T cell responses were contributed the tumor growth suppression. This anti-tumor effect of K3-SPG monotherapy was also confirmed by using various tumor models including pancreatic cancer peritoneal dissemination model. Taken together, nano-particulate TLR9 agonist injected intravenously can scout out tumor microenvironment to provoke local innate immune activation and release dead tumor cells into circulation that may induce broader and protective tumor antigen-specific CD8 T cells.
CpG-ODN; β-glucan; innate immunity; immunogenic cell death; phagocytes
Nasal vaccination has the potential to elicit systemic and mucosal immunity against pathogens. However, split and subunit vaccines lack potency at stimulating mucosal immunity, and an adjuvant is indispensable for eliciting potent mucosal immune response to nasal vaccines. Endocine, a lipid-based mucosal adjuvant, potentiates both systemic and mucosal immune responses. Although Endocine has shown efficacy and tolerability in animal and clinical studies, its mechanism of action remains unknown. It has been reported recently that endogenous danger signals are essential for the effects of some adjuvants such as alum or MF59. However, the contribution of danger signals to the adjuvanticity of Endocine has not been explored. Here, we show that RNA is likely to be an important mediator for the adjuvanticity of Endocine. Administration of Endocine generated nucleic acids release, and activated dendritic cells (DCs) in draining lymph nodes in vivo. These results suggest the possibility that Endocine indirectly activates DCs via damage-associated molecular patterns. Moreover, the adjuvanticity of Endocine disappeared in mice lacking TANK-binding kinase 1 (Tbk1), which is a downstream molecule of nucleic acid sensing signal pathway. Furthermore, co-administration of RNase A reduced the adjuvanticity of Endocine. These data suggest that RNA is important for the adjuvanticity of Endocine.
The innate immune protein Stimulator of interferon genes (STING) promotes the induction of interferon beta (IFN-β) production via the phosphorylation of its C-terminal tail (CTT) by TANK-binding kinase 1 (TBK1). Potent ligands of STING are, therefore, promising candidates for novel anti-cancer drugs or vaccine adjuvants. However, the intrinsically flexible CTT poses serious problems in in silico drug discovery. Here, we performed molecular dynamics simulations of the STING fragment containing the CTT in ligand-bound and unbound forms and observed that the binding of a potent ligand cyclic GMP-AMP (cGAMP) induced a local structure in the CTT, reminiscent of the known structure of a TBK1 substrate. The subsequent molecular biological experiments confirmed the observed dynamics of the CTT and identified essential residues for the activation of the IFN-β promoter, leading us to propose a new mechanism of STING activation.
•The binding of the potent ligand cGAMP to STING induces local structural ordering in the flexible C-terminal tail of STING.•Site-directed mutagenesis studies, designed based on this observation, elucidated residues essential for STING function.•The local structure formation in the CTT was shown to be essential for the induction of IFN-β production.
STING C-terminal tail, Molecular dynamics simulation, Type I IFNs, TBK1; cGAMP.
Cancer cells contain a small population of cancer stem cells or cancer initiating cells, which can be enriched in the side population (SP) after fluorescence activated cell sorting. To examine the members of the ADAM, ADAMTS and MMP gene families related to phenotypes of the SP and the main population (MP), we screened the expression of all the members in the propagated SP and MP of A549 lung adenocarcinoma cells, and found that the relative expression ratio of ADAM23 in the MP to the SP is most highly increased, but none of them are increased in the SP. A similar result on the ADAM23 expression was obtained with another cell line, Calu‐3 cells. Overexpression of ADAM23 inhibited colony formation, cell adhesion and migration, and knockdown of ADAM23 by shRNA showed the reverse effects. ADAM23‐mediated suppression of colony formation, cell adhesion and migration was greatly reduced by treatment with neutralizing anti‐ADAM23 antibody, anti‐αvβ3 integrin antibody and/or ADAM23 disintegrin peptide. Expression of cancer stem cell‐related genes, including AKRC1/2, TM4SF1 and NR0B1, was increased by knockdown of ADAM23. In addition, lung metastasis of A549 transfectants with different levels of ADAM23 expression was negatively regulated by the ADAM23 expression levels. Our data provide evidence that ADAM23 plays a role in suppression of cancer cell progression through interaction with αvβ3 integrin, and suggest that downregulation of ADAM23 in SP cells may contribute toward providing a cancer stem cell phenotype by facilitating the activity of integrin αvβ3.
ADAM23; colony formation; metastasis; non‐small cell lung carcinoma cells; side population
Intestinal immune homeostasis requires dynamic crosstalk between innate and adaptive immune cells. Dendritic cells (DCs) exist as multiple phenotypically and functionally distinct sub-populations within tissues, where they initiate immune responses and promote homeostasis. In the gut, there exists a minor DC subset defined as CD103+CD11b− that also expresses the chemokine receptor XCR1. In other tissues, XCR1+ DCs cross-present antigen and contribute to immunity against viruses and cancer, however the roles of XCR1+ DCs and XCR1 in the intestine are unknown. We showed that mice lacking XCR1+ DCs are specifically deficient in intraepithelial and lamina propria (LP) T cell populations, with remaining T cells exhibiting an atypical phenotype and being prone to death, and are also more susceptible to chemically-induced colitis. Mice deficient in either XCR1 or its ligand, XCL1, similarly possess diminished intestinal T cell populations, and an accumulation of XCR1+ DCs in the gut. Combined with transcriptome and surface marker expression analysis, these observations lead us to hypothesise that T cell-derived XCL1 facilitates intestinal XCR1+ DC activation and migration, and that XCR1+ DCs in turn provide support for T cell survival and function. Thus XCR1+ DCs and the XCR1/XCL1 chemokine axis have previously-unappreciated roles in intestinal immune homeostasis.
New adjuvants for cancer immunotherapy
Accumulated evidence obtained from various clinical trials and animal studies suggested that cancer vaccines need better adjuvants than those that are currently licensed, which include the most commonly used alum and incomplete Freund’s adjuvant, because of either a lack of potent anti-tumor immunity or the induction of undesired immunity. Several clinical trials using immunostimulatory adjuvants, particularly agonistic as well as non-agonistic ligands for TLRs, C-type lectin receptors, retinoic acid-inducible gene I-like receptors and stimulator of interferon genes, have revealed their therapeutic potential not only as vaccine adjuvants but also as anti-tumor agents. Recently, combinations of such immunostimulatory or immunomodulatory adjuvants have shown superior efficacy over their singular use, suggesting that seeking optimal combinations of the currently available or well-characterized adjuvants may provide a better chance for the development of novel adjuvants for cancer immunotherapy.
β-glucan; combination; CpG ODN; STING; TLR
Various silver-coated implants have been developed to prevent implant-associated infections, and have shown dramatic effects in vitro. However, the in vivo results have been inconsistent. Recent in vitro studies showed that silver exerts antibacterial activity by mediating the generation of reactive oxygen species in the presence of oxygen. To maintain its antibacterial activity in vivo, the silver should remain in an ionic state and be stably bound to the implant surface. Here, we developed a novel bacteria-resistant hydroxyapatite film in which ionic silver is immobilized via inositol hexaphosphate chelation using a low-heat immersion process. This bacteria-resistant coating demonstrated significant antibacterial activity both in vitro and in vivo. In a murine bioluminescent osteomyelitis model, no bacteria were detectable 21 days after inoculation with S. aureus and placement of this implant. Serum interleukin-6 was elevated in the acute phase in this model, but it was significantly lower in the ionic-silver group than the control group on day 2. Serum C-reactive protein remained significantly higher in the control group than the ionic-silver group on day 14. Because this coating is produced by a low-heat immersion process, it can be applied to complex structures of various materials, to provide significant protection against implant-associated infections.
Inflammatory bowel diseases (IBDs) accompany a critical loss of the frontline barrier function that is achieved primarily by intestinal epithelial cells (IECs). Although the gene-regulation pathways underlying these host-defense roles of IECs presumably are deranged during IBD pathogenesis, the quantitative and qualitative alterations of posttranscriptional regulators such as microRNAs (miRNAs) within the cells largely remain to be defined. We aimed to uncover the regulatory miRNA–target gene relationships that arise differentially in inflamed small- compared with large-IECs. Whereas IBD significantly increased the expression of only a few miRNA candidates in small-IECs, numerous miRNAs were upregulated in inflamed large-IECs. These marked alterations might explain why the large, as compared with small, intestine is more sensitive to colitis and shows more severe pathology in this experimental model of IBD. Our in-depth assessment of the miRNA–mRNA expression profiles and the resulting networks prompts us to suggest that miRNAs such as miR-1224, miR-3473a, and miR-5128 represent biomarkers that appear in large-IECs upon IBD development and co-operatively repress the expression of key anti-inflammatory factors. The current study provides insight into gene-regulatory networks in IECs through which dynamic rearrangement of the involved miRNAs modulates the gene expression–regulation machinery between maintaining and disrupting gastrointestinal homeostasis.
Agonists for TLR9 and Stimulator of IFN Gene (STING) act as vaccine adjuvants that induce type-1 immune responses. However, currently available CpG oligodeoxynucleotide (ODN) (K-type) induces IFNs only weakly and STING ligands rather induce type-2 immune responses, limiting their potential therapeutic applications. Here, we show a potent synergism between TLR9 and STING agonists. Together, they make an effective type-1 adjuvant and an anticancer agent. The synergistic effect between CpG ODN (K3) and STING-ligand cyclic GMP–AMP (cGAMP), culminating in NK cell IFN-γ (type-II IFN) production, is due to the concurrent effects of IL-12 and type-I IFNs, which are differentially regulated by IRF3/7, STING, and MyD88. The combination of CpG ODN with cGAMP is a potent type-1 adjuvant, capable of inducing strong Th1-type responses, as demonstrated by enhanced antigen-specific IgG2c and IFN-γ production, as well as cytotoxic CD8+ T-cell responses. In our murine tumor models, intratumoral injection of CpG ODN and cGAMP together reduced tumor size significantly compared with the singular treatments, acting as an antigen-free anticancer agent. Thus, the combination of CpG ODN and a STING ligand may offer therapeutic application as a potent type-II IFN inducer.
Adjuvant; cGAMP; CpG ODN; IFN-γ; STING; TLR
The development of cancer immunotherapies is progressing rapidly with a variety of technological approaches. They consist of “cancer vaccines”, which are based on the idea of vaccination, “effector cell therapy”, classified as passive immunotherapy, and “inhibition of immunosuppression”, which intends to break immunological tolerance to autoantigens or immunosuppressive environments characterizing antitumor immune responses. Recent reports showing clinical evidence of efficacy of immune checkpoint inhibitors and adoptive immunotherapies with tumor‐infiltrating lymphocytes and tumor‐specific receptor gene‐modified T cells indicate the beginning of a new era for cancer immunotherapy. This guidance summarizes ideas that will be helpful to those who plan to develop cancer immunotherapy. The aims of this guidance are to discuss and offer important points in early phase clinical studies of innovative cancer immunotherapy, with future progress in this field, and to contribute to the effective development of cancer immunotherapy aligned with the scope of regulatory science. This guidance covers cancer vaccines, effector cell therapy, and inhibition of immunosuppression, including immune checkpoint inhibitors.
Cancer vaccines; cell therapy; clinical trial; immunotherapy; monoclonal antibodies
Spinal extradural arachnoid cyst (SEDAC) is a cyst in the spinal canal that protrudes into the epidural space from a defect in the dura mater and leads to neurological disturbances. We previously showed that familial SEDAC is caused by FOXC2 mutation; however, the causal gene of sporadic SEDAC has not been identified. To identify the causal gene of sporadic SEDAC, we performed whole exome sequencing for 12 subjects with sporadic SEDAC and identified heterozygous HOXD4 loss-of-function mutations in three subjects. HOXD4 haplo-insufficiency causes SEDAC and a transcriptional network containing HOXD4 and FOXC2 is involved in the development of the dura mater and the etiology of SEDAC.
Oxidative stress has been reported to be involved in numerous human diseases, including musculoskeletal disorders such as osteoarthritis. However, the interaction between intervertebral disc (IVD) degeneration and oxidative stress is not well understood. The purpose of the present study was to elucidate the contribution of oxidative stress to IVD degeneration and the efficacy of antioxidant treatment for degenerative discs.
The expression level of an oxidative stress marker, nitrotyrosine, was assessed by immunohistochemistry and Western blotting. For evaluating intracellular reactive oxygen species (ROS) levels and oxidative stress in rat annulus fibrosus (AF) cells, flow cytometry and luciferase assay with an OKD48 construct were performed. The grade of IVD degeneration was assessed by magnetic resonance imaging and histological analysis.
A high frequency of nitrotyrosine-positive cells was observed in rat and human degenerative discs. mRNA expression of catabolic factors such as tumor necrosis factor-alpha (TNF-alpha), matrix metalloprotease-3 (MMP-3), and cyclooxygenase-2 (COX-2) was significantly induced by treatment with H2O2 or buthionine sulfoximine, whereas that of aggrecan, an important chondrogenic proteoglycan, was reduced in a dose-dependent manner. Treatment with mitogen-activated protein kinase (MAPK) inhibitors blocked the inductive effect of excessive ROS on COX-2 mRNA expression. Western blotting confirmed the phosphorylation of MAPKs in H2O2 and BSO-treated AF cells. Conversely, we showed that TNF-α induced oxidative stress with increased intracellular ROS levels in AF cells. Treatment with the antioxidant N-acetyl cysteine (NAC) abrogated the catabolic effect of excessive ROS and TNF-alpha in vitro. Finally, we showed that oral administration of NAC prevented IVD degeneration in rat degenerative model.
A positive feedback loop was formed between excessive ROS and TNF-alpha in AF cells. Thus, oxidative stress contributes to the progression of IVD degeneration and NAC can be a therapeutic option for IVD degeneration.
Electronic supplementary material
The online version of this article (doi:10.1186/s13075-015-0834-8) contains supplementary material, which is available to authorized users.
Intervertebral disc degeneration; Oxidative stress; Reactive oxygen species; Antioxidant
Numerous monoclonal antibodies (mAb) targeting tumor antigens have recently been developed. Antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) via effector cells such as tumor-infiltrating natural killer (NK) cells and macrophages are often involved in mediating the antitumor activity of mAb. CpG oligodeoxynucleotides (ODN) have a potent antitumor activity and are considered to increase tumor infiltration of NK cells and macrophages. Our group previously reported significant antitumor activity of anti-bone marrow stromal antigen 2 (BST2) mAb against BST2-positive endometrial cancer cells through ADCC. In this study, we evaluated the synergistic antitumor activity of combination therapy with anti-BST-2 mAb and CpG ODN using SCID mice and elucidated the mechanisms underlying this activity. Anti-BST2 mAb and CpG ODN monotherapy had a significant dose-dependent antitumor activity (P = 0.0135 and P = 0.0196, respectively). Combination therapy with anti-BST2 mAb and CpG ODN had a significant antitumor activity in SCID mice (P < 0.01), but not in NOG mice. FACS analysis revealed significantly increased numbers of NK cells and macrophages in tumors treated with a combination of anti-BST2 mAb and CpG ODN and with CpG ODN alone in SCID mice (P < 0.05 and P < 0.01, respectively). These results suggested that the combination therapy with anti-BST2 mAb and CpG ODN has a significant antitumor activity and induces tumor infiltration of NK cells and macrophages. Combination therapy with CpG ODN and anti-BST2 mAb or other antitumor mAb depending on ADCC may represent a new treatment option for cancer.
Antitumor antibody; bone marrow stromal antigen 2; CpG oligodeoxynucleotides; macrophage; natural killer cell
Spinal extradural arachnoid cyst (SEDAC) is a cyst in the spinal canal, which causes spinal cord compression and subsequent neurological damage. We previously identified two FOXC2 mutations in two SEDAC families. The FOXC2 mutations have been shown to be responsible for lymphedema-distichiasis syndrome (LDS), which includes SEDAC as an occasionally associated phenotype. We encountered a non-familial patient with SEDAC associated with LDS, and identified a novel nonsense mutation in FOXC2, c.349C>T (p.Q117*).
Temporal changes in the in situ germination flux of cysts and the abundance of vegetative cells of the toxic dinoflagellate Alexandrium catenella were investigated in Ago Bay, central Japan from July 2003 to December 2004. The in situ germination flux (cells m−2 day−1) was measured using ‘plankton emergence trap/chambers (PET chambers)’. Germination of the cysts in the sediments occurred continuously during the study, ranging from 52 to 1753 cells m−2 day−1, with no temporal trend. This germination pattern appeared to be promoted by a short mandatory dormancy period for newly formed cysts coupled with a broad temperature window for germination. For the vegetative populations, high abundances (>105 cells m−2) were recorded in the water column from spring to summer and from autumn to early winter. The size of the vegetative populations did not correlate with the cyst germination flux but rather larger vegetative populations were often observed when the water temperature was around 20°C, indicating that bloom development was mainly regulated by the temperature. Nonetheless, the continuous germination pattern of A. catenella is advantageous enabling the germinated cells to immediately exploit favorable bloom conditions.
Alexandrium catenella; cyst; in situ germination; bloom formation; population dynamics
Immunostimulatory CpG ODNs have been developed and utilized as TLR9-dependent innate immune activators and vaccine adjuvants. Four different types of immunostimulatory CpG ODNs (A/D, B/K, C, and P type) have been reported. A/D type ODNs are characterized by high IFN-α production but intrinsically form aggregates, hindering its good manufacturing practice grade preparation. In this study, we developed several D35-derived ODNs (a commonly used A/D type ODN), which were modified with the addition of a phosphorothioate polynucleotide tail (such as dAs40), and examined their physical properties, solubility in saline, immunostimulatory activity on human PBMCs, and vaccine adjuvant potential in monkeys. We found that two modified ODNs including D35-dAs40 and D35core-dAs40 were immunostimulatory, similar to original D35 in human PBMCs, resulting in high IFN-α secretion in a dose-dependent manner. Physical property analysis by dynamic light scattering revealed that both D35-dAs40 and D35core-dAs40 did not form aggregates in saline, which is currently impossible for the original D35. Furthermore, D35-dAs40 and D35core-dAs40 worked as better vaccine adjuvant in monkeys. These results suggested that D35-dAs40 and D35core-dAs40 are two promising prototypes of nonaggregating A/D type ODN with advantages of ease of drug preparation for clinical applications as vaccine adjuvants or IFN-α inducing immunomodifiers.
The skin is a key route of human exposure to nanomaterials, which typically occurs simultaneously with exposure to other chemical and environmental allergen. However, little is known about the hazards of nanomaterial exposure via the skin, particularly when accompanied by exposure to other substances.
Repeated topical treatment of both ears and the shaved upper back of NC/Nga mice, which are models for human atopic dermatitis (AD), with a mixture of mite extract and silica nanoparticles induced AD-like skin lesions. Measurements of ear thickness and histologic analyses revealed that cutaneous exposure to silica nanoparticles did not aggravate AD-like skin lesions. Instead, concurrent cutaneous exposure to mite allergens and silica nanoparticles resulted in the low-level production of allergen-specific IgGs, including both the Th2-related IgG1 and Th1-related IgG2a subtypes, with few changes in allergen-specific IgE concentrations and in Th1 and Th2 immune responses. In addition, these changes in immune responses increased the sensitivity to anaphylaxis. Low-level IgG production was induced when the mice were exposed to allergen–silica nanoparticle agglomerates but not when the mice exposed to nanoparticles applied separately from the allergen or to well-dispersed nanoparticles.
Our data suggest that silica nanoparticles themselves do not directly affect the allergen-specific immune response after concurrent topical application of nanoparticles and allergen. However, when present in allergen-adsorbed agglomerates, silica nanoparticles led to a low IgG/IgE ratio, a key risk factor of human atopic allergies. We suggest that minimizing interactions between nanomaterials and allergens will increase the safety of nanomaterials applied to skin.
Electronic supplementary material
The online version of this article (doi:10.1186/s12989-015-0095-3) contains supplementary material, which is available to authorized users.
Atopic dermatitis; Agglomerate; Aggregate; Anaphylaxis; Blocking antibody; IgE; IgG; Mite; Nanomaterials; Nanoparticles; Particulate matter
The immunoreceptor NKG2D originally identified in natural killer cells recognizes ligands that are upregulated on tumor cells. Expression of NKG2D ligands (NKG2DLs) is activated by the DNA damage response (DDR) which is often activated constitutively in cancer cells, revealing them to natural killer cells as a mechanism of immunosurveillance. Here we report that the induction of retinoic acid early transcript 1 (RAE1) ligands for NKG2D by the DDR relies on a STING-dependent DNA sensor pathway involving the effector molecules TBK1 and IRF3. Cytosolic DNA was detected in lymphoma cell lines which express RAE1 and its occurrence required activation of the DDR. Transfection of DNA into ligand-negative cells was sufficient to induce RAE1 expression. Irf3+/−;Eμ-Myc mice expressed lower levels of RAE1 on tumor cells and showed a reduced survival rate compared to Irf3+/+;Eμ-Myc mice. Taken together, our results suggest that genomic damage in tumor cells leads to activation of STING-dependent DNA sensor pathways, thereby activating RAE1 and enabling tumor immunosurveillance.
Innate immunity; NK cells; DNA sensor; DNA damage response; NKG2D
Vertebral hemangiomas are common; however, aggressive vertebral hemangiomas with extraosseous extensions causing neurological deficits are rare. The treatment for this subtype of hemangioma remains controversial, since there are few reports on long-term clinical outcomes or tumor recurrence rates. We describe a case of aggressive vertebral hemangioma treated by total en bloc spondylectomy, with a literature review focusing on long-term recurrence. A 52-year-old male with a two-month history of numbness in the bilateral lower extremities was referred to our hospital. Imaging studies showed a tumor originating in the T9 vertebra and extending to the T8 and T10 vertebrae, with extraosseous extension causing spinal-cord compression. Ten months after onset, the patient presented with progressive paraparesis and hypalgesia. Total en bloc spondylectomy was performed, and pathology was consistent with cavernous hemangioma. Motor and sensory deficits improved significantly, and no signs of recurrence are seen at 2.5 years after operation. A review of literature revealed a recurrence rate of 12.7% (10/79 cases). The available evidence indicates satisfactory long-term outcomes for total tumor resection without adjuvant radiotherapy.
Cyclodextrins are commonly used as a safe excipient to enhance the solubility and bioavailability of hydrophobic pharmaceutical agents. Their efficacies and mechanisms as drug-delivery systems have been investigated for decades, but their immunological properties have not been examined. In this study, we reprofiled hydroxypropyl-β-cyclodextrin (HP-β-CD) as a vaccine adjuvant and found that it acts as a potent and unique adjuvant. HP-β-CD triggered the innate immune response at the injection site, was trapped by MARCO+ macrophages, increased Ag uptake by dendritic cells, and facilitated the generation of T follicular helper cells in the draining lymph nodes. It significantly enhanced Ag-specific Th2 and IgG Ab responses as potently as did the conventional adjuvant, aluminum salt (alum), whereas its ability to induce Ag-specific IgE was less than that of alum. At the injection site, HP-β-CD induced the temporary release of host dsDNA, a damage-associated molecular pattern. DNase-treated mice, MyD88-deficient mice, and TBK1-deficient mice showed significantly reduced Ab responses after immunization with this adjuvant. Finally, we demonstrated that HP-β-CD–adjuvanted influenza hemagglutinin split vaccine protected against a lethal challenge with a clinically isolated pandemic H1N1 influenza virus, and the adjuvant effect of HP-β-CD was demonstrated in cynomolgus macaques. Our results suggest that HP-β-CD acts as a potent MyD88- and TBK1-dependent T follicular helper cell adjuvant and is readily applicable to various vaccines.
Background: RNA:DNA hybrids exist in the nucleus and mitochondria but not in the cytosol, except in viral infection.
Results: RNA:DNA hybrids exist in the cytosol of various human cells and are mediated by RNA polymerase III (Pol III), which regulates the microRNA machinery.
Conclusion: Cytosolic RNA:DNA hybrids are regulated by Pol III.
Significance: Previous unknown cytosolic RNA:DNA hybrids may have physiological relevance to miRNA machinery and RNA transport.
RNA:DNA hybrids form in the nuclei and mitochondria of cells as transcription-induced R-loops or G-quadruplexes, but exist only in the cytosol of virus-infected cells. Little is known about the existence of RNA:DNA hybrids in the cytosol of virus-free cells, in particular cancer or transformed cells. Here, we show that cytosolic RNA:DNA hybrids are present in various human cell lines, including transformed cells. Inhibition of RNA polymerase III (Pol III), but not DNA polymerase, abrogated cytosolic RNA:DNA hybrids. Cytosolic RNA:DNA hybrids bind to several components of the microRNA (miRNA) machinery-related proteins, including AGO2 and DDX17. Furthermore, we identified miRNAs that are specifically regulated by Pol III, providing a potential link between RNA:DNA hybrids and the miRNA machinery. One of the target genes, exportin-1, is shown to regulate cytosolic RNA:DNA hybrids. Taken together, we reveal previously unknown mechanism by which Pol III regulates the presence of cytosolic RNA:DNA hybrids and miRNA biogenesis in various human cells.
Cancer; DNA Damage; Innate Immunity; MicroRNA (miRNA); RNA Polymerase III; RNA Transport; RNA:DNA Hybrid; RNase H; Antibody S9.6
Small bowel angioectasia is reported as the most common cause of bleeding in patients with obscure gastrointestinal bleeding. Although the safety and efficacy of endoscopic treatment have been demonstrated, rebleeding rates are relatively high. To establish therapeutic and follow-up guidelines, we investigated the long-term outcomes and clinical predictors of rebleeding in patients with small bowel angioectasia.
A total of 68 patients were retrospectively included in this study. All the patients had undergone CE examination, and subsequent control of bleeding, where needed, was accomplished by endoscopic argon plasma coagulation. Based on the follow-up data, the rebleeding rate was compared between patients who had/had not undergone endoscopic treatment. Multivariate analysis was performed using Cox proportional hazard regression model to identify the predictors of rebleeding. We defined the OGIB as controlled if there was no further overt bleeding within 6 months and the hemoglobin level had not fallen below 10 g/dl by the time of the final examination.
The overall rebleeding rate over a median follow-up duration of 30.5 months (interquartile range 16.5–47.0) was 33.8% (23/68 cases). The cumulative risk of rebleeding tended to be lower in the patients who had undergone endoscopic treatment than in those who had not undergone endoscopic treatment, however, the difference did not reach statistical significance (P = 0.14). In the majority of patients with rebleeding (18/23, 78.3%), the bleeding was controlled by the end of the follow-up period. Multiple regression analysis identified presence of multiple lesions (≥3) (OR 3.82; 95% CI 1.30–11.3, P = 0.02) as the only significant independent predictor of rebleeding.
In most cases, bleeding can be controlled by repeated endoscopic treatment. Careful follow-up is needed for patients with multiple lesions, presence of which is considered as a significant risk factor for rebleeding.
Capsule endoscopy (CE); Balloon-assisted endoscopy (BAE); Small bowel angioectasia; Obscure gastrointestinal bleeding (OGIB); Argon plasma coagulation (APC)