Evaluation of the AV7909 Anthrax Vaccine Toxicity in Sprague Dawley Rats Following Three Intramuscular Administrations

AV7909 is a next-generation anthrax vaccine under development for post-exposure prophylaxis following suspected or confirmed Bacillus anthracis exposure, when administered in conjunction with the recommended antibacterial regimen. AV7909 consists of the FDA-approved BioThrax® vaccine (anthrax vaccine adsorbed) and an immunostimulatory Toll-like receptor 9 agonist oligodeoxynucleotide adjuvant, CPG 7909. The purpose of this study was to evaluate the potential systemic and local toxicity of AV7909 when administered via repeat intramuscular injection to the right thigh muscle (biceps femoris) to male and female Sprague Dawley rats. The vaccine was administered on Days 1, 15, and 29 and the animals were assessed for treatment-related effects followed by a 2-week recovery period to evaluate the persistence or reversibility of any toxic effects. The AV7909 vaccine produced no apparent systemic toxicity based on evaluation of clinical observations, body weights, body temperature, clinical pathology, and anatomic pathology. Necrosis and inflammation were observed at the injection sites as well as in regional lymph nodes and adjacent tissues and were consistent with immune stimulation. Antibodies against B. anthracis protective antigen (PA) were detected in rats treated with the AV7909 vaccine, confirming relevance of this animal model for the assessment of systemic toxicity of AV7909. In contrast, sera of rats that received saline or soluble CPG 7909 alone were negative for anti-PA antibodies. Overall, 3 intramuscular immunizations of Sprague Dawley rats with AV7909 were well tolerated, did not induce mortality or any systemic adverse effects, and did not result in any delayed toxicity.

A Targeted Nano Drug Delivery System of AS1411 Functionalized Graphene Oxide Based Composites

A novel method for the preparation of antitumor drug vehicles has been optimized. Biological materials of chitosan oligosaccharide (CO) and γ-polyglutamic acid (γ-PGA) have previously been employed as modifiers to covalently modify graphene oxide (GO), which in turn loaded doxorubicin (DOX) to obtain a nano drug delivery systems of graphene oxide based composites (GO-CO-γ-PGA-DOX). The system was not equipped with the ability of initiative targeting, thus resulting into toxicity and side effects on normal tissues or organs. In order to further improve the targeting property of the system, the nucleic acid aptamer NH2 -AS1411 (APT) of targeted nucleolin (C23) was used to conjugate on GO-CO-γ-PGA to yield the targeted nano drug delivery system APT-GO-CO-γ-PGA. The structure, composition, dispersion, particle size and morphology properties of the synthesized complex have been studied using multiple characterization methods. Drug loading and release profile data showed that APT-GO-CO-γ-PGA is provided with high drug loading capacity and is capable of controlled and sustained release of DOX. Cell experimental results indicated that since C23 was overexpressed on the surface of Hela cells but not on the surface of Beas-2B cells, APT-GO-CO-γ-PGA-DOX can target Hela cells and make increase toxicity to Hela cells than Beas-2B cells, and the IC50 value of APT-GO-CO-γ-PGA-DOX was 3.23±0.04 μg/mL. All results proved that APT-GO-CO-γ-PGA can deliver antitumor drugs in a targeted manner, and achieve the effect of reducing poison, which indicated that the targeted carrier exhibits a broad application prospect in the field of biomedicine.

Improved Treatment Options for Glaucoma with Brimonidine-Loaded Lipid DNA Nanoparticles

Glaucoma is the second leading cause of irreversible blindness worldwide. Among others, elevated intraocular pressure (IOP) is one of the hallmarks of the disease. Antiglaucoma drugs such as brimonidine can lower the IOP but their adherence to the ocular surface is low, leading to a low drug uptake. This results in a frequent dropping regime causing low compliance by the patients. Lipid DNA nanoparticles (NPs) have the intrinsic ability to bind to the ocular surface and can be loaded with different drugs. Here, we report DNA NPs functionalized for loading of brimonidine through specific aptamers and via hydrophobic interactions with double stranded micelles. Both NP systems exhibited improved affinity toward the cornea and retained release of the drug as compared to controls both in vitro and in vivo. Both NP types were able to lower the IOP in living animals significantly more than pristine brimonidine. Importantly, the brimonidine-loaded NPs showed no toxicity and improved efficacy and hence should improve compliance. In conclusion, this drug-delivery system offers high chances of an improved treatment for glaucoma and thus preserving vision in the aging population.

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.

Exposure to stimulatory CpG oligonucleotides during gestation induces maternal hypertension and excess vasoconstriction in pregnant rats

Bacterial infections increase risk for pregnancy complications, such as preeclampsia and preterm birth. Unmethylated CpG DNA sequences are present in bacterial DNA and have immunostimulatory effects. Maternal exposure to CpG DNA induces fetal demise and craniofacial malformations; however, the effects of CpG DNA on maternal cardiovascular health have not been examined. We tested the hypothesis that exposure to synthetic CpG oligonucleotides (ODNs) during gestation would increase blood pressure and cause vascular dysfunction in pregnant rats. Pregnant and nonpregnant female rats were treated with CpG ODN (ODN 2395) or saline (Veh) starting on gestational day 14or corresponding day for the nonpregnant groups. Exposure to CpG ODN increased systolic blood pressure in pregnant (Veh: 121 ± 2 mmHg vs. ODN 2395: 134 ± 2 mmHg,P< 0.05) but not in nonpregnant rats (Veh: 111 ± 2 mmHg vs. ODN 2395: 108 ± 5 mmHg,P> 0.05). Mesenteric resistance arteries from pregnant CpG ODN-treated rats had increased contractile responses to U46619 [thromboxane A2(TxA2) mimetic] compared with arteries from vehicle-treated rats [Emax(%KCl), Veh: 87 ± 4 vs. ODN 2395: 104 ± 4,P< 0.05]. Nitric oxide synthase (NOS) inhibition increased contractile responses to U46619, and CpG ODN treatment abolished this effect in arteries from pregnant ODN 2395-treated rats. CpG ODN potentiated the involvement of cyclooxygenase (COX) to U46619-induced contractions. In conclusion, exposure to CpG ODN during gestation induces maternal hypertension, augments resistance artery contraction, increases the involvement of COX-dependent mechanisms and reduces the contribution of NOS-dependent mechanisms to TxA2-induced contractions in mesenteric resistance arteries.

Intraperitoneal and subcutaneous injections of the TLR9 agonist ODN 1668 in rats: brain inflammatory responses are related to peripheral IL-6 rather than interferons

Subcutaneous or intraperitoneal administration of Toll-like receptor (TLR)-9 agonist, ODN 1668 caused moderate fever and anorexia. In comparison to stimulation of other intracellular TLRs, activation of TLR9 did not result in pronounced peripheral induction of interferons, but rather induced interleukin-6. Expression of cytokines (TNFα, IL-1β) and inducible forms of enzymes for prostaglandin E2 synthesis occurred in the brain, in conjunction with a moderate activation of the transcription factors STAT3 and NF-IL6 in brain endothelial cells. The lack of a septic-like state in ODN 1668-treated rats reinforces the therapeutic value of this drug.

Near-infrared light-triggered, targeted drug delivery to cancer cells by aptamer gated nanovehicles

A novel cell-targeting, near-infrared light-responsive drug delivery platform based on mesoporous silica-coated gold nanorods that are surface-functionalized with aptamer DNA is constructed. Aptamer DNA is used as both capping and targeting agent. In vitro studies show the feasibility of using this nanocarrier for targeted and noninvasive remote controlled drug delivery and photothermal therapy.

Phase 1 trial of AMA1-C1/Alhydrogel plus CPG 7909: an asexual blood-stage vaccine for Plasmodium falciparum malaria

Background

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.

Methods

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 µg of AMA1-C1/Alhydrogel®+564 µg CPG 7909 (n = 15), 80 µg of AMA1-C1/Alhydrogel® (n = 30), or 80 µg of AMA1-C1/Alhydrogel+564 µg CPG 7909 (n = 30).

Results

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 µg or 80 µg of AMA1-C1/Alhydrogel+CPG 7909 had up to 14 fold significant increases in anti-AMA1 antibody concentration compared to 80 µg 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.

Conclusion/Significance

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.

Trial Registration

ClinicalTrials.gov NCT00344539

Interaction of CpG-oligodeoxynucleotides with Toll like receptor 9 induces apoptosis and modulates metaloproteinase-2 activity in human intestinal epithelium

Recent reports have indicated different effects of immunostimulatory sequences containing CpG-Oligodeoxynucleotides (ODN) on various immune cells. However, the exact role of CpG-ODN in the human gut is unclear. In the present study, we assessed potential effects of CpG-ODN on non lymphoid cell (intestinal epithelial cell line HT-29) on a dose-response and time-course basis. Intestinal epithelial cell line HT-29 was treated with CpG-ODN (CpG 2006) and lipopolysaccharide (LPS) at 5, 10, 25, 50 microg/ ml and 1, 5, 10 microg/ ml concentrations, respectively. Following treatments, dose- response and time-course cytotoxicity using a colorimetric method, Metaloproteinase-2 (MMP-2) activity (using gelatin zymography) and apoptosis (using annexin-v flowcytometry method) assays were performed. Chloroquine treatment was also used for its inhibitory effect on endosomal acidification process to verify specific CpG-ODN and Toll Like Receptor 9 (TLR9) interactions. Cytotoxicity analysis of CpG-ODN showed that CpG-ODN increased significantly the proliferation of CpG-ODN treated cells, as compared to untreated cells, at concentrations of 10-25 microg/ml (p < 0.05). Overall MMP-2 activity analysis showed significant differences between treated and untreated cells. However, minimal changes were observed when MMP-2 activity was assessed per cell. Moreover, CpG-ODN treated cells demonstrated an increasing apoptosis rate of 0.8 %, 6.46 % and 14.21% at concentrations of 5, 10, 25 microg/ml, respectively. Collectively, our data indicated that intestinal epithelial cell line HT-29 is highly responsive to CpG effect in vitro and exhibits modified activities. The direct CpG-ODN and TLR-9 interactions in HT-29 cells could provide new approaches in malignant tumor therapeutic strategies.

Cytotoxic G-rich oligodeoxynucleotides: putative protein targets and required sequence motif

It has recently been shown that certain oligodeoxynucleotides (ODNs) designed as catalytic DNA molecules (DNAzymes) exhibit potent cytotoxicity independent of RNA-cleavage activity in a number of cell lines. These cytotoxic ODNs all featured a 5' G-rich sequence and induced cell death by a TLR9-independent mechanism. In this study, we examined the sequence and length dependence of ODNs for cytotoxicity. A G-rich sequence at the 5' terminus of the molecule was necessary for cytotoxicity and the potency of ODNs with active 5' sequences was length dependent. Cytotoxicity appeared to be generally independent of 3' sequence composition, although 3' sequences totally lacking G-nucleotides were mostly inactive. Nucleolin, elongation factor 1-alpha (eEF1A) and vimentin were identified as binding to a cytotoxic ODN (Dz13) using protein pull-down assays and LC-MS/MS. Although these proteins have previously been described to bind G-rich ODNs, the binding of eEF1A correlated with cytotoxicity, whereas binding of nucleolin and vimentin did not. Quiescent non-proliferating cells were resistant to cytotoxicity, indicating cytotoxicity may be cell cycle dependent. Although the exact mechanism of cytotoxicity remains unknown, marked potency of the longer (> or =25 nt) ODNs in particular, indicates the potential of these molecules for treatment of diseases associated with abnormal cell proliferation.

The newly identified CpG-N ODN208 protects mice from challenge with CpG-S ODN by decreasing TNF-alpha release

Administration of an excess of oligodeoxynucleotides containing immunostimulatory CpG motifs (CpG-S ODNs) may induce systemic inflammatory response syndrome (SIRS) and sepsis. Therefore, it is important to develop neutralizing CpG ODNs (CpG-N ODNs), which can be used to reduce the release of cytokines induced by the presence of CpG-S ODNs. In the present study, CpG-N ODN208 (5'-TGCCGCGGCAGA-3'), a neutralizing twelve-oligodeoxynucleotide molecule recently identified in our laboratory, inhibited TNF-alpha release from human peripheral blood mononuclear cells (hPBMCs) and murine RAW264.7 cells induced by CpG-S ODN exposure in a dose- and time-dependent manner. Flow cytometry revealed that CpG-N ODN208 decreased cell-surface binding and internalization of 6-FAM-CpG-S ODN. However, the decreased cell-surface binding and internalization of CpG-S ODN could not completely account for the decreased TNF-alpha release. RT-PCR experiments revealed that CpG-N ODN treatment could down-regulate the CpG-S ODN-induced upregulation of Toll-like receptor 9 (TLR9) mRNA expression. This finding suggested that the decreased cytokine release following CpG-N ODN treatment might be related to decreased TLR9 mRNA expression. In in vivo experiments, no protection was found when the ratio of CpG-N ODN to CpG-S ODN delivered to mice was 3:1. However, at a 5:1 ratio, CpG-N ODN208 could protect mice from an ordinarily lethal dose of CpG-S ODN. Furthermore, we found that CpG-N ODN208 treatment decreased serum TNF-alpha levels in mice injected with sublethal doses of CpG-S ODN whether the CpG-N ODN208 was added prior to or concurrent with the CpG-S ODN. Our results demonstrated that CpG-N ODN-mediated protection against a lethal challenge by CpG-S ODN was associated with the reduction of TNF-alpha release.

Lipoplexes prepared from cationic liposomes and mammalian DNA induce CpG-independent, direct cytotoxic effects in cell cultures and in mice

BACKGROUND

Recent studies demonstrated the cytotoxic activity of bacterial DNA (pDNA) complexed with cationic lipids. This cytotoxicity is related to the ability of pDNA to induce potently the immune system, which is associated with release of inflammatory cytokines. Both activities seem to be related to the nonmethylated CpG sequences present in the pDNA. Here we study the cytotoxic activity of nonbacterial DNA complexed with cationic lipids against various tumor cell lines.

METHODS

Various nucleic acids complexed with cationic liposomes were prepared and their cytotoxic activity was studied in cell cultures and in tumor-bearing mice. Cell uptake of lipoplexes was evaluated, and mechanism of DNA cytotoxic activity was studied.

RESULTS

We found that nonbacterial (vertebrate) genomic DNA when complexed with cationic lipids is highly cytotoxic against C-26 and M-109 tumor cells. Cationic lipids alone were not toxic to these cells. The cytotoxic activity does not result from nonspecific acidification of the intracellular milieu, as substitution of DNA by poly-L-glutamate did not result in cytotoxicity, although the level of uptake of anionic charges per cell was similar to that of the nucleic acids, suggesting that this cytotoxic effect is specific to nucleic acids. By studying the nucleic acid fate using confocal microscopy, we found that cytotoxicity correlated with the release of DNA into the cytoplasm following uptake of lipoplexes. Injection of calf thymus DNA-based lipoplexes to mice with peritoneal C-26 metastases resulted in doubling of median survival time and long-term survival in 20% of the tumor-bearing mice. Judging by low levels of IFN-gamma, TNF-alpha and IL-6 in the treated mice, this effect cannot be ascribed to Th-1 inflammation, but rather to a direct cytotoxic effect on the tumor cells.

CONCLUSIONS

The above data provide a new insight into the mechanisms of lipoplex-mediated antitumor effects in vitro and in vivo and new perspectives in cancer therapy.

Improving the therapeutic index of CpG oligodeoxynucleotides by intralymphatic administration

Signal transduction initiated by TLR such as TLR9, a natural receptor for unmethylated cytosine-guanine-rich motifs (CpG), results in activation of transcription factors, including NF-kappaB, with substantial impact on the innate and adaptive immunity. However, practical application of new adjuvants such as CpG oligodeoxynucleotides (ODN) remains a challenge, since prominent systemic activation of NF-kappaB may result in severe side effects reminiscent of septic shock, thus limiting their therapeutic index (TI). Low-dose administration of CpG ODN into lymph nodes has been evaluated as a means to reduce systemic side effects while retaining strong adjuvant properties. To this aim, a prototype immune-stimulating CpG ODN was used to enhance the antibody production against the antigen phospholipase A(2) and the CD8(+) T cell responses to ovalbumin in mice. When administered subcutaneously, high CpG ODN doses (>10 nmol) were required to enhance antibody and CD8(+) T cell responses. In contrast, when administered directly into a lymph node, much lower amounts of CpG (<0.1 nmol) were sufficient for a similar immune-enhancing effect. Systemic adverse reactions induced by CpG ODN were only detected at higher doses (1-10 nmol), independently of the route of administration. Finally, low-dose CpG ODN, administered in a targeted fashion to HLA-A2.1(+) transgenic mice, greatly elevated anti-tumor CD8(+) T cell immunity. Thus, intralymphatic administration of CpG ODN considerably improves the TI and may greatly enable a safe and effective use in the clinic.

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.

Bovine and ovine blood mononuclear leukocytes differ markedly in innate immune responses induced by Class A and Class B CpG-oligodeoxynucleotide

Cytosine-phosphate-guanosine (CpG)-DNA can induce an impressive array of innate immune responses that may directly or indirectly contribute to the clearance of infectious agents. Assays, such as lymphocyte proliferative responses, have been used to demonstrate that the immunostimulatory activity of CpG-DNA is conserved among a broad range of vertebrate species, but no studies have been completed to determine if qualitative differences exist among species for CpG-oligodeoxynucleotide (ODN)-induced innate immune responses. In this study, we assessed the capacity of a Class A (ODN 2216) and a Class B (ODN 2007) CpG-ODN to induce innate immune responses in two closely related species, ovine (n = 28) and bovine (n = 29). The secretion of interferon (IFN)-alpha and IFN-gamma and non-major histocompatability complex (MHC)-restricted cytotoxic activity were assayed with CpG-ODN-stimulated peripheral blood mononuclear cells (PBMC). These investigations revealed significant interspecies and intraspecies variation in the responses. As expected, ODN 2216 was a potent inducer of IFN-alpha secretion by both bovine and ovine PBMC, but ODN 2007 also induced dose-dependent, CpG-specific IFN-alpha secretion by ovine PBMC. In contrast, a significant dose-dependent, CpG-specific IFN-gamma secretion response was only observed following ODN 2216 stimulation of bovine PBMC. Furthermore, both ODN 2216 and ODN 2007 induced CpG-specific non-MHC-restricted cytotoxicity with ovine but not bovine PBMC. Finally, there was not a single assay in which PBMC from all sheep or cattle responded at a detectable level. A striking aspect of these results is that such marked differences in CpG-ODN induced innate responses existed both between and within two closely related species.

Impact of site-specific nucleobase deletions on the arthritogenicity of DNA

Oligodeoxynucleotides (ODN) containing unmethylated CpG motifs (CpG ODN) potently stimulate the innate and acquired immune system. We have compared the in vivo and in vitro inflammatogenic properties of CpG ODNs containing a specific nucleobase deletion either 5'-upstream (ODN-2) or 3'-downstream (ODN-3) of the CpG motif, comparing with a prototype CpG ODN (ODN-1). The frequency of arthritis was similar after intra-articular (i.a.) injections of ODN-1 or ODN-3, but was significantly lower (p < 0.02) after i.a. injections of ODN-2. In vitro production of the pro-inflammatory cytokine TNF-alpha was higher in mouse spleen cell cultures exposed to ODN-2 in comparison to ODN-1. In addition, the level of IL-10 induced by ODN-2 was higher than that induced by ODN-1. On the other hand, TNF-alpha, IL-10, and MCP-1 levels, as well as splenocyte proliferative responses were all significantly lower for ODN-3 than for ODN-1. These results suggest that a 5'-upstream nucleobase deletion reduces arthritogenicity, while maintaining or increasing the production of pro- and anti-inflammatory factors. In contrast, a 3'-downstream nucleobase deletion has no effect on arthritogenicity, despite significantly lower levels of proliferation and pro- and anti-inflammatory cytokines, compared with ODN-1. This study indicates that specific structural elements within the ODN sequence but outside the CpG motif, modulate the immunostimulatory properties of CpG ODNs.

How do glucocorticoids compare to oligo decoys as inhibitors of collagen synthesis and potential toxicity of these therapeutics?

This article demonstrates how glucocorticoids decrease collagen synthesis. The parameters used to assess procollagen synthesis in our laboratory will be compared to those used by others. This article will note all the pertinent literature on the molecular mechanisms of this down regulation of procollagen synthesis. For example, what are the effects of glucocorticoids at the levels of transcription and translation of collagen mRNAs? Finally, we will define a molecular mechanism to inhibit Type I collagen synthesis by decreasing the binding of the TGF-beta activator protein complex to the TGF-beta element in the distal promoter of the proalpha1 Type I collagen gene, preventing the 2:1 ratio of alpha1 to alpha2 chains in the processed Type I collagen molecule. We will next ask "How do sense oligo decoys decrease Type I collagen synthesis at the in vivo and at the cell levels?" In primary fibrotic cell culture, the double-stranded phosphorothioate oligodeoxynucleotide decoys were more effective than their sense single-stranded counterparts. The molecular mechanism for the decrease in Type I collagen synthesis is the same as glucocorticoids, that is by decreasing the binding of the TGF-beta activator protein complex to the TGF-beta element in the distal promoter of the proalpha1 Type I collagen gene for the transcription of the proalpha1 mRNAs. The reason for using sense oligo decoys as anti-fibrotic agents as compared to the anti-fibrotic glucocorticoids, is that presently marketed and FDA approved glucocorticoids have many untoward side effects which the sense oligo decoys do not have.

In vitro cytotoxicity of unsaturated oligo[poly(ethylene glycol) fumarate] macromers and their cross-linked hydrogels

Currently, oligo[poly(ethylene glycol) fumarate] (OPF) hydrogels are being investigated as an injectable and biodegradable system for tissue engineering applications. In this study, cytotoxicity of each component of the OPF hydrogel formulation and the resulting cross-linked network was examined. Specifically, OPF synthesized with poly(ethylene glycol) (PEG) of different molecular weights (MW), the cross-linking agent [PEG-diacrylate (PEG-DA)], and the redox initiator pair [ammonium persulfate (APS) and ascorbic acid (AA)] were evaluated for cytotoxicity at 2 and 24 h using marrow stromal cells (MSCs) as model cells. The effect of leachable byproducts of OPF hydrogels on cytotoxicity was also investigated. Upon exposure to various concentrations of OPF for 2 h, greater than 50% of the MSCs were viable, regardless of OPF molecular weight or concentration in the media. After 24 h, the MSCs maintained more than 75% viability except for OPF concentrations higher than 25% (w/v). When examining the cross-linking agent, PEG-DA of higher MW (3400) demonstrated significantly higher viability compared to PEG-DA with MW 575 at all concentrations tested. Considering initiators, when MSCs were exposed to AA and APS, as well as the combination of AA and APS, higher viability was observed at lower concentrations. Once cross-linked, the leachable products from the OPF hydrogels had minimal adverse effects on the viability of MSCs (percentage of live cells was higher than 90% regardless of hydrogel types). The results suggest that, after optimization of cross-linking parameters, OPF-based hydrogels hold promise as novel injectable scaffolds or cell carriers in tissue engineering.

CpG-ODN-induced inflammation is sufficient to cause T-cell-mediated autoaggression against hepatocytes

Autoimmune diseases are often associated with microbial infections. Molecular mimicry between microbial antigens and self-epitopes has been suggested as a mechanism for breaking self-tolerance and induction of autoimmunity. Since infections also cause inflammatory responses we explored the role of local inflammation in organ-specific autoimmunity. For this purpose, transgenic mice were used expressing the MHC class I molecule Kb exclusively on hepatocytes. These mice exhibit Kb-specific tolerance as exemplified by the acceptance of Kb+ grafts. Inflammatory reactions were induced by injection of immunostimulatory cytosine-phosphorothioate-guanine (CpG)-rich oligodeoxynucleotides (ODN). Application of CpG-ODN is sufficient to break tolerance in vivo, and to cause activation of Kb-specific CD8+ T cells and subsequent autoaggression against hepatocytes. The CpG-ODN-induced inflammation appears to have two major effects. First, it causes infiltration of T cells into the liver parenchyma. Second, adhesion and costimulatory molecules are up-regulated on hepatocytes so that the infiltrating CD8+ T cells encounter Kb on hepatocytes, which display an APC-like phenotype, resulting in activation and tissue damage. Autoimmune hepatitis can be maintained for at least eight weeks by repeated application of CpG-ODN but subsides after termination of the inflammatory stimulus, suggesting the requirement of additional factors for a self-perpetuation of autoimmunity. These observations describe an additional pathway for the induction of autoimmunity, i.e. in the absence of microbial antigens inflammatory reactions alone can lead to infiltration of T cells into organs, resulting in breaking of tolerance and autoaggression. Moreover, the results provide evidence that T cell activation can take place not only in draining lymph nodes but also directly on parenchymal cells.

Uptake dynamics and retinal tolerance of phosphorothioate oligonucleotide and its direct delivery into the site of choroidal neovascularization through subretinal administration in the rat

This study aimed to investigate uptake dynamics and retinal tolerance of phosphorothioate oligonucleotides (PS-oligos) following subretinal injection. A fluorescent-labeled PS-oligo (FL-oligo) with random sequence was administered into the subretinal space of rat by transsclera-choroid-retinal pigment epithelium (RPE) injection at doses of 0.129, 1.29, and 12.9 microg in 2.0 microl solution. The uptake dynamics were evaluated by fundus fluorescent photography in real time and by fluorescence microscopy using flat mounts and cryosections. Immunophenotyping for CD4+, CD8+ cytotoxic lymphocytes, and CD68+ macrophages was performed to assess cellular infiltration in the retina. In addition, the FL-oligo was injected subretinally in a rat model of choroidal neovascularization (CNV) for direct delivery into the site of CNV. Subretinal administration of FL-oligo resulted in both dose-dependent and time-dependent distribution in the retina, where it accessed the RPE and all layers of the neuroretina. CD4+, CD8+ cytotoxic lymphocytes, and CD68+ macrophages were observed at the site of needle penetration. However, in areas far from the injection site where the FL-oligo appeared strongly, cellular infiltration was absent, and the retinal morphology was preserved very well. The FL-oligo was successfully delivered into the site of intense laser photocoagulation. It was predominantly localized to the RPE, macrophages, and some choroid cells and remained detectable for at least 56 days after injection. Our results demonstrate for the first time that subretinal injection efficiently introduced PS-oligo into the RPE and neuroretina with an acceptable level of safety. Subretinal administration of antiangiogenic oligonucleotides may hold great potential for the treatment of CNV.

Oligonucleotide enhanced cytotoxicity of Idarubicin for lymphoma cells

Oligonucleotides offer the potential to manipulate gene expression in targeted cells which might be exploitable for therapeutic benefit. The effects of combining a phosphorothioate oligonucleotide OL(1) p53, which transiently down-regulates p53 levels, with an anthracycline, Idarubicin, on the growth of wild-type p53 WMN gene-expressing lymphoma cells was evaluated. Fluorescent OL(1) p53, was used to demonstrate oligonucleotide uptake and retention by the WMN cells. Uptake was maximal at 24 hours and compared to baseline (0 hours) increasing apoptotic cells were evident in WMN cells treated with OL(1) (1 microM) alone and in combination with Idarubicin (0.2 nM) for 24 to 48 hours. In cells treated with OL(1) p53 and Idarubicin, truncated p53 message of a predicted 201 base pair length based on RNAase H cleavage of the OL(1) p53-p53 mRNA heteroduplex was detected after 7 hours of incubation. The message for p53 was transiently downregulated as detected by RT-PCR analysis at 24 hours, and protein levels transiently reduced at 36 hours, as shown by a quantitative Western blot. Corresponding to these events, the growth of WMN cells ceased after 48 hours in the concurrent presence of OL(1) p53 and Idarubicin and, the lymphoma cells were dead after 72 hours. No reduction in hematopoietic colony forming cell capacity of similarly treated hematopoietic progenitor cells harvested from cytokine-mobilized blood by apheresis was observed. Therefore, synergistic cytotoxicity of Idarubicin for lymphoma cells treated with an oligonucleotide targeting p53 message was demonstrated at oligonucleotide and Idarubicin concentrations which were minimally toxic to hematopoietic progenitor cells. This approach offers new opportunities for purging of lymphoma cells from hematopoietic harvests and systemic lymphoma therapy.

Pharmacokinetic and toxicity profile of a phosphorothioate oligonucleotide following inhalation delivery to lung in mice

Antisense oligonucleotides are currently being investigated for the treatment of a variety of diseases. Antisense drugs are being administered primarily by parenteral injection. To explore more convenient patient delivery methods, we have characterized the tissue kinetics and tolerability of an inhaled aerosol formulation of a phosphorothioate oligonucleotide in mice. Concentrations of oligonucleotide in bronchioalveolar lavage fluid, plasma, and tissue and immunohistochemical localization were used to assess deposition and pharmacokinetic parameters. Significant concentrations of oligonucleotide in lung, as well as systemic tissues, were measured following a pulmonary dose of 12 mg/kg. Doses as low as 1-3 mg/kg also produced significant concentrations of oligonucleotide (>50 microg oligonucleotide per gram of tissue), and these were maintained in the lung with a halflife of 20 hours or greater. Oligonucleotide was localized to bronchiolar epithelium and alveolar epithelium and endothelium. Toxicity was mild at the 12 mg/kg level and minimal to absent at doses of 3 mg/kg or below. Based on a favorable pharmacokinetic profile and a relative lack of toxicity, inhalation delivery appears to be a therapeutic option for antisense oligonucleotides.

The immunobiology and clinical potential of immunostimulatory CpG oligodeoxynucleotides

Over 100 years ago, Coley first explored the use of bacterial products as immunostimulatory therapy for nonbacterial disease. It is now clear that bacterial DNA, and synthetic oligodeoxynucleotides containing specific motifs centered on a CpG dinucleotide (CpG ODN), are potent immunostimulatory agents. The molecular mechanisms responsible for the immunostimulatory effects of CpG ODN have yet to be elucidated fully, although it is clear that CpG ODN act rapidly on a variety of cell types. This includes activation of B cells, natural killer cells, and antigen-presenting cells including monocytes, macrophages, and dendritic cells. These effects have led to evaluation of CpG ODN as immune adjuvants in immunization where they have been shown in animal models to enhance the development of a TH1-type immune response. Preliminary results from clinical trials using CpG ODN as an immune adjuvant are promising. Preclinical studies suggest CpG ODN can also enhance innate immunity against a variety of infections, synergize with monoclonal antibody to enhance antibody-dependent cellular cytotoxicity, and alter the Th1/Th2 balance as a possible treatment for allergic diseases and asthma. Clinical evaluation has recently begun to determine whether promising preclinical results with CpG ODN can be translated into effective and tolerable clinical treatment approaches.

CpG-DNA upregulates the major acute-phase proteins SAA and SAP

The acute-phase response is an immediate reaction of the host against invading microorganisms. We show here that oligodeoxynucleotides (ODNs) containing a CpG motif rapidly induce the major murine acute-phase proteins in vivo, i.e. serum amyloid A (SAA) and serum amyloid P (SAP). Serum levels of these proteins are elevated within 12 h and peak at 24 h after the injection of CpG-ODN or endotoxin. Liver cells produce the proteins with the same kinetics. Injection of interleukin 6 (IL-6), IL-1beta and tumour necrosis factor alpha (TNF-alpha) induces SAA and SAP in vivo, but the CpG-ODN-mediated induction does not depend on the presence of the TNF receptor p55, as the acute-phase response in TNF receptor p55-deficient mice does not differ from that of wild-type mice. Aside from CpG-ODN, bacterial genomic DNA also induces the acute-phase response in LPS-resistant C3H/Hej mice. The induction of the major acute-phase proteins SAA and SAP is blocked by the simultaneous injection of CpG-ODN together with D-galactosamine (D-GalN). As D-GalN sensitizes the host for the toxic effects of TNF-alpha, a possible mechanism could be the prevention of synthesis of the major acute-phase proteins SAA and SAP.

Radiotoxicity of iodine-125-labeled oligodeoxyribonucleotides in mammalian cells

We investigated the distribution, stability and radiotoxicity of 125I-oligodeoxyribonucleotides (125I-ODN) in human fibrosarcoma HT-1080 cells to study the radiotoxic effects of the Auger electron emitter 125I delivered to the cells by ODN.

METHODS

We delivered 125I-ODN into the cells via complexing with a liposomal delivery system. To assess the intracellular distribution and stability of 125I-ODN delivered by the liposomal delivery system, we used autoradiography, fluorescent and confocal microscopy and electrophoresis. To study the radiotoxicity of the unbound 125I-ODN, we used a clonogenic assay. The radiotoxicity of 125I-ODN delivered by the liposomal delivery system was compared with that of freely diffusible 125I-antipyrine, membrane-excluded 125I-bovine serum albumin and DNA incorporated 125I-deoxyuridine (125I-UdR).

RESULTS

Oligodeoxyribonucleotides accumulated in the cell nucleus within a few hours of incubation. On the basis of the number of decays at 37% survival, 125I-ODN are 2 times more radiotoxic than 125I-antipyrine, which is freely diffusible into cells, and 8 times more radiotoxic than 125I-bovine serum albumin, which remains outside cells. However, the radiotoxicity of unbound 125I-ODN is almost 3 orders of magnitude lower than that of DNA-incorporated 125I-UdR. The 125I-ODN are not significantly degraded by intracellular nucleases during the time of uptake incubation.

CONCLUSION

The dramatic difference in radiotoxicity between 125I-ODN and 125I-UdR confirms that, despite the nuclear localization, 125I-ODN are not bound to or incorporated within the genomic DNA. Our data demonstrate that the radiotoxicity of Auger electron emitters is determined by the radiation dose delivered to nuclear DNA, not necessarily to the nucleus. Therefore, relatively high intracellular concentrations of unbound 125I-ODN can be achieved without causing significant cell death.

Toxicologic effects of an oligodeoxynucleotide phosphorothioate and its analogs following intravenous administration in rats

The aim of the present study is to evaluate the in vivo toxicologic effects of a phosphorothioate oligodeoxynucleotide (PS oligo) and three of its analogs [PS oligo containing four methylphosphonate linkages at the 3' and 5'-ends (MBO 1), PS oligo containing four 2'-O-methylribonucleosides at both the 3'- and 5'-ends (MBO 2), and PS oligo containing an 8 bp loop region at the 3'-end (self-stabilized oligo)]. Oligodeoxynucleotides were administrated intravenously to male and female rats at doses of 3, 10, and 30 mg/kg/day for 14 days. Rats were killed on day 15, blood samples were collected for hematology and clinical chemistry determinations, and tissues, including lymph nodes, spleens, livers, and kidneys, were subjected to pathologic examinations. The toxicity profiles of the four oligodeoxynucleotides were very similar, but differed in magnitude. In terms of the severity of the abnormalities caused by the oligodeoxynucleotides, the order was MBO 2 > PS oligo > self-stabilized oligo > MBO 1. Alterations in hematology parameters included thrombocytopenia, anemia, and neutropenia. Abnormalities in clinical chemistry parameters observed with PS oligo or MBO 2 were dose-dependent elevation of liver transaminases and reduction of the levels of alkaline phosphatase, albumin, and total protein. In addition, MBO 2 caused elevation of the total bilirubin level in male rats at the 30 mg/kg dose. No major alterations in hematology or clinical chemistry were observed in rats receiving MBO 1 or self-stabilized oligo. Dose-dependent enlargements of spleen, liver, and kidney were observed, especially in rats receiving PS oligo and MBO 2. Pathologic studies showed a generalized hyperplasia of the reticuloendothelial (RE) system in the tissues examined. Alterations in the spleen were mainly RE cell hyperplasia and hematopoietic cell proliferation. In addition to RE cell hyperplasia, lymph nodes showed necrosis, hepatocytes showed cytologic alterations and necrosis, and kidneys showed renal tubule regeneration. The severity of pathologic changes observed was oligodeoxynucleotide dependent, in the order of MBO 2 > PS oligo > self-stabilized oligo > MBO 1.

Effect of a metallothionein antisense oligonucleotide on embryo development

The effect of a metallothionein (MT) antisense oligodeoxynucleotide (ODN) on mouse preimplantation embryo development was investigated. Preimplantation embryos were cultured for 72 h and examined following exposure to either an MT antisense or sense ODN. Blastocyst formation (cavitation) and embryo cell number were lower in embryos exposed to the MT antisense ODN than in controls or in embryos exposed to the MT sense ODN. In embryos cultured in medium containing free nucleotides, cavitation frequency was not affected, although mean embryo cell number was lower than in controls. Combined, this work shows that an antisense ODN against MT can significantly affect blastocyst formation of preimplantation embryos; some, but not all, of the observed effects on embryo cell number may have been due to nucleotide toxicity.

Biologic and therapeutic significance of MYB expression in human melanoma

We investigated the therapeutic potential of employing antisense oligodeoxynucleotides to target the disruption of MYB, a gene which has been postulated to play a pathogenetic role in cutaneous melanoma. We found that MYB was expressed at low levels in several human melanoma cell lines. Also, growth of representative lines in vitro was inhibited in a dose- and sequence-dependent manner by targeting the MYB gene with unmodified or phosphorothioate-modified antisense oligodeoxynucleotides. Inhibition of cell growth correlated with specific decrease of MYB mRNA. In SCID mice bearing human melanoma tumors, infusion of MYB antisense transiently suppressed MYB gene expression but effected long-term growth suppression of transplanted tumor cells. Toxicity of the oligodeoxynucleotides was minimal in mice, even when targeted to the murine Myb gene. These results suggest that the MYB gene may play an important, though undefined, role in the growth of at least some human melanomas. Inhibition of MYB expression might be of use in the treatment of this disease.

Suppression of Philadelphia1 leukemia cell growth in mice by BCR-ABL antisense oligodeoxynucleotide

When injected into SCID mice, the Philadelphia chromosome-positive chronic myeloid leukemia-blast crisis cell line BV173 induces a disease process closely resembling that seen in leukemia patients. At 1 and 3 weeks after injection of 10(6) BV173 cells, CD10+ cells were detected in the bone marrow of the mice, leukemic colonies grew from bone marrow and spleen cell suspensions, and BCR-ABL transcripts were detectable in bone marrow, spleen, peripheral blood, liver, and lungs. Systemic treatment of the leukemic mice with a 26-mer BCR-ABL antisense oligodeoxynucleotide (1 mg/day for 9 days) induced disappearance of CD10+ and clonogenic leukemic cells and a marked decrease in BCR-ABL mRNA in mouse tissues. Untreated mice or mice treated with a BCR-ABL sense oligodeoxynucleotide or a 6-base-mismatched antisense oligodeoxynucleotide oligodeoxynucleotide were dead 8-13 weeks after leukemia cell injection; in marked contrast, mice treated with BCR-ABL antisense oligodeoxynucleotide died of leukemia 18-23 weeks after injection of leukemic cells. These findings provide evidence for the in vivo effectiveness of an anticancer therapy based on antisense oligodeoxynucleotides targeting a tumor-specific gene.

Selective cytotoxicity to human leukemic myeloblasts produced by oligodeoxyribonucleotide phosphorothioates complementary to p53 nucleotide sequences

Cells were treated in vitro with oligodeoxyribonucleotide phosphorothioates (ODNs) complementary to sites common to both wild-type and mutant p53 nucleotide sequences. Acute myelogenous leukemia (AML) blasts from peripheral blood were exposed to four different p53 ODNs and showed anti-leukemic effects in suspension culture. This effect continued after removal of the ODN from the medium. Blocking of self-renewal of the leukemic blast stem cells in secondary plating of cells from cloning assays by two of the p53 ODNs was also observed. Control ODNs had no effect on leukemic blasts. Treatment of normal bone marrow cells with the four p53 ODNs did not influence their growth, nor was there any effect by the p53 ODNs on the leukemic cell-line, HL60, that does not express p53. These data suggest that p53 ODNs are selectively toxic to primary myelogenous blasts and may be therapeutically useful in AML.

Site-specific mutagenesis of the human fibroblast interferon gene

Human fibroblast interferon has three cysteine residues, located at amino acid positions 17, 31, and 141. Using the technique of site-specific mutagenesis with a synthetic oligonucleotide primer, we changed the codon for cysteine-17 to a codon for serine. The resulting interferon, IFN-beta Ser-17, retains the antiviral, natural killer cell activation, and antiproliferative activities of native fibroblast interferon. The purified IFN-beta Ser-17 protein has an antiviral specific activity of 2 X 10(8) units/mg, similar to that of purified native fibroblast interferon. In addition, the purified protein is stable to long-term storage at -70 degrees C.