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149 result(s) for "Oligodeoxyribonucleotides - toxicity"
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CPG 7909, an Immunostimulatory TLR9 Agonist Oligodeoxynucleotide, as Adjuvant to Engerix-B HBV Vaccine in Healthy Adults: A Double-Blind Phase I/II Study
Oligodeoxynucleotides containing immunostimulatory CpG motifs (CpG ODN) act as potent Th1-like immune enhancers with many antigens in animal models. We have extended these observations to the first clinical evaluation of the safety, tolerability and immunogenicity of CPG 7909 when added to a commercial HBV vaccine. In a randomized, double-blind phase I dose escalation study, healthy volunteers aged 18-35 years were vaccinated at 0, 4 and 24 weeks by intramuscular injection with Engerix-B (GlaxoSmithKline). The regular adult dose of 20 microg recombinant hepatitis B surface antigen (HBsAg) adsorbed to alum was administered mixed with saline (control) or with CPG 7909 at one of three doses (0.125, 0.5 or 1.0 mg). HBsAg-specific antibody responses (anti-HBs) appeared significantly sooner and were significantly higher at all timepoints up to and including 24 weeks in CPG 7909 recipients compared to control subjects (p< or = 0.001). Strikingly, most CpG 7909-vaccinated subjects developed protective levels of anti-HBs IgG within just two weeks of the priming vaccine dose. A trend towards higher rates of positive cytotoxic T cell lymphocyte responses was noted in the two higher dose groups of CPG 7909 compared to controls. The most frequently reported adverse events were injection site reactions, flu-like symptoms and headache. While these were more frequent in CPG 7909 groups than in the control group (p<0.0001), most were reported to be of mild to moderate intensity regardless of group. In summary, CPG 7909 as an adjuvant to Engerix-B was well-tolerated and enhanced vaccine immunogenicity. CPG 7909 may allow the development of a two-dose prophylactic HBV vaccine.
Phase 1 Trial of AMA1-C1/Alhydrogel plus CPG 7909: An Asexual Blood-Stage Vaccine for Plasmodium falciparum Malaria
Apical Membrane Antigen 1 (AMA1), a polymorphic merozoite surface protein, is a leading blood-stage malaria vaccine candidate. This is the first reported use in humans of an investigational vaccine, AMA1-C1/Alhydrogel, with the novel adjuvant CPG 7909. A phase 1 trial was conducted at the University of Rochester with 75 malaria-naive volunteers to assess the safety and immunogenicity of the AMA1-C1/Alhydrogel+CPG 7909 malaria vaccine. Participants were sequentially enrolled and randomized within dose escalating cohorts to receive three vaccinations on days 0, 28 and 56 of either 20 microg of AMA1-C1/Alhydrogel+564 microg CPG 7909 (n = 15), 80 microg of AMA1-C1/Alhydrogel (n = 30), or 80 microg of AMA1-C1/Alhydrogel+564 microg CPG 7909 (n = 30). Local and systemic adverse events were significantly more likely to be of higher severity with the addition of CPG 7909. Anti-AMA1 immunoglobulin G (IgG) were detected by enzyme-linked immunosorbent assay (ELISA), and the immune sera of volunteers that received 20 microg or 80 microg of AMA1-C1/Alhydrogel+CPG 7909 had up to 14 fold significant increases in anti-AMA1 antibody concentration compared to 80 microg of AMA1-C1/Alhydrogel alone. The addition of CPG 7909 to the AMA1-C1/Alhydrogel vaccine in humans also elicited AMA1 specific immune IgG that significantly and dramatically increased the in vitro growth inhibition of homologous parasites to levels as high as 96% inhibition. The safety profile of the AMA1-C1/Alhydrogel+CPG 7909 malaria vaccine is acceptable, given the significant increase in immunogenicity observed. Further clinical development is ongoing. ClinicalTrials.gov NCT00344539.
Curcumin Can Decrease Tissue Inflammation and the Severity of HSV-2 Infection in the Female Reproductive Mucosa
Herpes Simplex Virus Type 2 (HSV-2) is one of the most prevalent sexually transmitted viruses and is a known risk factor for HIV acquisition in the Female Genital Tract (FGT). Previously, we found that curcumin can block HSV-2 infection and abrogate the production of inflammatory cytokines and chemokines by genital epithelial cells in vitro. In this study, we investigated whether curcumin, encapsulated in nanoparticles and delivered by various in vivo routes, could minimize inflammation and prevent or reduce HSV-2 infection in the FGT. Female mice were pre-treated with curcumin nanoparticles through oral, intraperitoneal and intravaginal routes, and then exposed intravaginally to the tissue inflammation stimulant CpG-oligodeoxynucleotide (ODN). Local intravaginal delivery of curcumin nanoparticles, but not intraperitoneal or oral delivery, reduced CpG-mediated inflammatory histopathology and decreased production of pro-inflammatory cytokines Interleukin (IL)-6, Tumor Necrosis Factor Alpha (TNF-α) and Monocyte Chemoattractant Protein-1 (MCP-1) in the FGT. However, curcumin nanoparticles did not demonstrate anti-viral activity nor reduce tissue pathology when administered prior to intravaginal HSV-2 infection. In an alternative approach, intravaginal pre-treatment with crude curcumin or solid dispersion formulations of curcumin demonstrated increased survival and delayed pathology following HSV-2 infection. Our results suggest that curcumin nanoparticle delivery in the vaginal tract could reduce local tissue inflammation. The anti-inflammatory properties of curcumin delivered to the vaginal tract could potentially reduce the severity of HSV-2 infection and decrease the risk of HIV acquisition in the FGT of women.
CpG-containing immunostimulatory DNA sequences elicit TNF-α–dependent toxicity in rodents but not in humans
CpG-containing immunostimulatory DNA sequences (ISS), which signal through TLR9, are being developed as a therapy for allergic indications and have proven to be safe and well tolerated in humans when administrated via the pulmonary route. In contrast, ISS inhalation has unexplained toxicity in rodents, which express TLR9 in monocyte/macrophage lineage cells as well as in plasmacytoid DCs (pDCs) and B cells, the principal TLR9-expressing cells in humans. We therefore investigated the mechanisms underlying this rodent-specific toxicity and its implications for humans. Mice responded to intranasally administered 1018 ISS, a representative B class ISS, with strictly TLR9-dependent toxicity, including lung inflammation and weight loss, that was fully reversible and pDC and B cell independent. Knockout mouse experiments demonstrated that ISS-induced toxicity was critically dependent on TNF-alpha, with IFN-alpha required for TNF-alpha induction. In contrast, human PBMCs, human alveolar macrophages, and airway-derived cells from Ascaris suum-allergic cynomolgus monkeys did not produce appreciable TNF-alpha in vitro in response to ISS stimulation. Moreover, sputum of allergic humans exposed to inhaled ISS demonstrated induction of IFN-inducible genes but minimal TNF-alpha induction. These data demonstrate that ISS induce rodent-specific TNF-alpha-dependent toxicity that is absent in humans and reflective of differential TLR9 expression patterns in rodents versus humans.
The impact of single and pairwise Toll-like receptor activation on neuroinflammation and neurodegeneration
Background Toll-like receptors (TLRs) enable innate immune cells to respond to pathogen- and host-derived molecules. The central nervous system (CNS) exhibits most of the TLRs identified with predominant expression in microglia, the major immune cells of the brain. Although individual TLRs have been shown to contribute to CNS disorders, the consequences of multiple activated TLRs on the brain are unclear. We therefore systematically investigated and compared the impact of sole and pairwise TLR activation on CNS inflammation and injury. Methods Selected TLRs expressed in microglia and neurons were stimulated with their specific TLR ligands in varying combinations. Cell cultures were then analyzed by immunocytochemistry, FlowCytomix, and ELISA. To determine neuronal injury and neuroinflammation in vivo , C57BL/6J mice were injected intrathecally with TLR agonists. Subsequently, brain sections were analyzed by quantitative real-time PCR and immunohistochemistry. Results Simultaneous stimulation of TLR4 plus TLR2, TLR4 plus TLR9, and TLR2 plus TLR9 in microglia by their respective specific ligands results in an increased inflammatory response compared to activation of the respective single TLR in vitro . In contrast, additional activation of TLR7 suppresses the inflammatory response mediated by the respective ligands for TLR2, TLR4, or TLR9 up to 24 h, indicating that specific combinations of activated TLRs individually modulate the inflammatory response. Accordingly, the composition of the inflammatory response pattern generated by microglia varies depending on the identity and combination of the activated TLRs engaged. Likewise, neuronal injury occurs in response to activation of only selected TLRs and TLR combinations in vitro . Activation of TLR2, TLR4, TLR7, and TLR9 in the brain by intrathecal injection of the respective TLR ligand into C57BL/6J mice leads to specific expression patterns of distinct TLR mRNAs in the brain and causes influx of leukocytes and inflammatory mediators into the cerebrospinal fluid to a variable extent. Also, the intensity of the inflammatory response and neurodegenerative effects differs according to the respective activated TLR and TLR combinations used in vivo. Conclusions Sole and pairwise activation of TLRs modifies the pattern and extent of inflammation and neurodegeneration in the CNS, thereby enabling innate immunity to take account of the CNS diseases’ diversity.
NF-κB Decoy Oligodeoxynucleotide Enhanced Osteogenesis in Mesenchymal Stem Cells Exposed to Polyethylene Particle
Excessive generation of wear particles after total joint replacement may lead to local inflammation and periprosthetic osteolysis. Modulation of the key transcription factor NF-κB in immune cells could potentially mitigate the osteolytic process. We previously showed that local delivery of ultrahigh-molecular-weight polyethylene (UHMWPE) particles recruited osteoprogenitor cells and reduced osteolysis. However, the biological effects of modulating the NF-κB signaling pathway on osteoprogenitor/mesenchymal stem cells (MSCs) remain unclear. Here we showed that decoy oligodeoxynucleotide (ODN) increased cell viability when primary murine MSCs were exposed to UHMWPE particles, but had no effects on cellular apoptosis. Decoy ODN increased transforming growth factor-beta 1 (TGF-β1) and osteoprotegerin (OPG) in MSCs exposed to UHMWPE particles. Mechanistic studies showed that decoy ODN upregulated OPG expression through a TGF-β1-dependent pathway. By measuring the alkaline phosphatase activity, osteocalcin levels, Runx2 and osteopontin expression, and performing a bone mineralization assay, we found that decoy ODN increased MSC osteogenic ability when the cells were exposed to UHMWPE particles. Furthermore, the cellular response to decoy ODN and UHMWPE particles with regard to cell phenotype, cell viability, and osteogenic ability was confirmed using primary human MSCs. Our results suggest that modulation of wear particle-induced inflammation by NF-κB decoy ODN had no adverse effects on MSCs and may potentially further mitigate periprosthetic osteolysis by protecting MSC viability and osteogenic ability.
A novel vaccine adjuvant comprised of a synthetic innate defence regulator peptide and CpG oligonucleotide links innate and adaptive immunity
There has been an increased demand for the development of novel vaccine adjuvants that lead to enhanced induction of protection from infectious challenges and development of immunological memory. A novel vaccine adjuvant was developed comprising a complex containing CpG oligonucleotide and the synthetic cationic innate defence regulator peptide HH2 that has enhanced immune modulating activities. The complex of HH2 and the CpG oligonucleotide 10101 was a potent inducer of cytokine/chemokine expression ex vivo, retained activity following extended storage, had low associated cytotoxicity, and upregulated surface marker expression in dendritic cells, a critical activity for a vaccine adjuvant. Immunization of mice with a coformulation of the HH2–CpG complex and pertussis toxoid significantly enhanced the induction of toxoid-specific antibody titres when compared to toxoid alone, inducing high titres of IgG1 and IgG2a, typical of a balanced Th1/Th2 response, and also led to high IgA titres. This study demonstrates the potential application of the HH2–CpG complex as a vaccine adjuvant.
Age-related differences in neuroinflammatory responses associated with a distinct profile of regulatory markers on neonatal microglia
Background The perinatal period is one in which the mammalian brain is particularly vulnerable to immune-mediated damage. Early inflammation in the central nervous system (CNS) is linked with long-term impairment in learning and behavior, necessitating a better understanding of mediators of neuroinflammation. We therefore directly examined how age affected neuroinflammatory responses to pathogenic stimuli. Methods In mice, susceptibility to neurological damage changes dramatically during the first few weeks of life. Accordingly, we compared neuroinflammatory responses to pathogen associated molecular patterns (PAMPs) of neonatal (two day-old) and weanling (21 day-old) mice. Mice were inoculated intracerebrally with PAMPs and the cellular and molecular changes in the neuroinflammatory response were examined. Results Of the 12 cytokines detected in the CNS following toll-like receptor 4 (TLR4) stimulation, ten were significantly higher in neonates compared with weanling mice. A similar pattern of increased cytokines in neonates was also observed with TLR9 stimulation. Analysis of cellular responses indicated a difference in microglial activation markers in the CNS of neonatal mice and increased expression of proteins known to modulate cellular activation including CD11a, F4/80 and CD172a. We also identified a new marker on microglia, SLAMF7, which was expressed at higher levels in neonates compared with weanlings. Conclusions A unique neuroinflammatory profile, including higher expression of several proinflammatory cytokines and differential expression of microglial markers, was observed in brain tissue from neonates following TLR stimulation. This increased neuroinflammatory response to PAMPs may explain why the developing brain is particularly sensitive to infection and why infection or stress during this time can lead to long-term damage in the CNS.
Inhibitory effects of STAT3 decoy oligodeoxynucleotides on human epithelial ovarian cancer cell growth in vivo
The signal transducer and activator of transcription 3 (STAT3) regulates target gene expression by binding to a consensus DNA sequence within the promoter of the target genes. The constitutive activation of STAT3 has been shown to contribute to tumorigenesis in ovarian cancer and it has been reported to be a key factor for drug resistance in ovarian cancer. STAT3-specific decoy oligodeoxynucleotides (ODNs) (STAT3 decoy ODNs) that contain a consensus DNA sequence inhibit the transcriptional activity of STAT3, leading to cancer cell death. However, their mechanisms of action are unclear and little information is available as to the effects and the toxicity of STAT3 decoy ODNs in vivo. In this study, we established subcutaneous xenografts of SKOV3 human ovarian cancer cells in nude mice, evaluated the antitumor effects of STAT3 decoy ODNs on xenografted nude mice, and investigated the mechanisms behind the antitumor effects of STAT3 decoy ODNs targeting the STAT3 signaling pathway in vivo. The results revealed that the STAT3 decoy ODN inhibited ovarian cancer cell growth and promoted ovarian cancer cell apoptosis in vivo. Western blot analysis indicated that the STAT3 decoy ODN downregulated the protein expression levels of matrix metalloproteinase (MMP)-2, MMP-9 and Bcl-2, and upregulated the protein expression levels of caspase-3 in vivo. H&E staining was used to detect the side-effects of the STAT3 decoy ODN in the vital organs of the nude mice. We found that there were no significant abnormalities in the vital organs of the nude mice apart from slight inflammation and necrosis in parts of the hepatic lobule. The data from the present study suggest that decoy ODNs targeting STAT3 may be an effective therapeutic approach for the treatment of ovarian cancer in vivo.
Preclinical toxicity and toxicokinetics of GTI-2040, a phosphorothioate oligonucleotide targeting ribonucleotide reductase R2
Purpose GTI-2040, a 20-mer phosphorothioate oligonucleotide, was designed to hybridize to the mRNA sequence of human ribonucleotide reductase R2. GTI-2040 has been shown to inhibit human cancer cell proliferation by downregulation of R2 expression in vitro and to significantly inhibit tumor growth in xenograft models of human cancer in mice. As part of the safety evaluation for human clinical trials, the toxicity and toxicokinetics of GTI-2040 were determined in Sprague–Dawley rats and rhesus monkeys. Methods GTI-2040 was administered to rats at 2, 10, and 50 mg/kg/day by bolus intravenous injection every second day for 21 days with a 21-day recovery. In monkeys, an acute study was performed with single, escalating doses of GTI-2040 ranging from 10 to 80 mg/kg given as a 24-h continuous intravenous infusion. As well, a 21-day, continuous intravenous infusion study with GTI-2040 was conducted in monkeys at 2, 10, and 50 mg/kg/day, with a 3-week recovery. Blood sampling was done to measure GTI-2040 plasma concentrations, metabolites, and pharmacokinetic parameters, and tissues were collected to assess the distribution of GTI-2040 and/or metabolites. Results The toxicities of GTI-2040 in both rats and monkeys were typical for the phosphorothioate oligonucleotide class of compounds. In monkeys, there was a dose-related increase in GTI-2040 plasma levels with concomitant increase in complement activation and prolongation of activated partial thromboplastin time. In both rats and monkeys, the tissues having the highest concentrations of GTI-2040 (kidney, liver, spleen) had the largest dose-related toxic effects. Adverse effects were diminished or absent in the recovery animals. Conclusions GTI-2040 was well tolerated when infused over 24 h at doses up to 80 mg/kg in monkeys. In rats and monkeys, GTI-2040 was reasonably well tolerated and showed reversible toxicities when administered at doses up to 50 mg/kg/day for 21 days. The no observed adverse effect dose level for GTI-2040 in both animal species was 2 mg/kg/day. There were no apparent sequence-specific effects related to the interaction of GTI-2040 with the R2 component of the mRNA expressing ribonucleotide reductase.