Christian Mueller Copyright (c) 2012 All rights reserved. http://works.bepress.com/christian_mueller Recent documents in Christian Mueller en-us Fri, 23 Nov 2012 11:34:11 PST 3600 Hepatocyte-specific hypoxia-inducible factor-1alpha is a determinant of lipid accumulation and liver injury in alcohol-induced steatosis in mice http://works.bepress.com/christian_mueller/35 http://works.bepress.com/christian_mueller/35 Tue, 30 Oct 2012 07:05:45 PDT Chronic alcohol causes hepatic steatosis and liver hypoxia. Hypoxia-regulated hypoxia-inducible factor 1-alpha, (HIF-1alpha) may regulate liporegulatory genes, but the relationship of HIF-1 to steatosis remains unknown. We investigated HIF-1alpha in alcohol-induced hepatic lipid accumulation. Alcohol administration resulted in steatosis, increased liver triglyceride levels, and increased serum alanine aminotransferase (ALT) levels, suggesting liver injury in wild-type (WT) mice. There was increased hepatic HIF-1alpha messenger RNA (mRNA), protein, and DNA-binding activity in alcohol-fed mice compared with controls. Mice engineered with hepatocyte-specific HIF-1 activation (HIF1dPA) had increased HIF-1alpha mRNA, protein, and DNA-binding activity, and alcohol feeding in HIF1dPA mice increased hepatomegaly and hepatic triglyceride compared with WT mice. In contrast, hepatocyte-specific deletion of HIF-1alpha [HIF-1alpha(Hep(-/-) )], protected mice from alcohol- and lipopolysaccharide (LPS)-induced liver damage, serum ALT elevation, hepatomegaly, and lipid accumulation. HIF-1alpha(Hep(-/-) ), WT, and HIF1dPA mice had equally suppressed levels of peroxisome proliferator-activated receptor alpha mRNA after chronic ethanol, whereas the HIF target, adipocyte differentiation-related protein, was up-regulated in WT mice but not HIF-1alpha(Hep(-/-) ) ethanol-fed/LPS-challenged mice. The chemokine monocyte chemoattractant protein-1 (MCP-1) was cooperatively induced by alcohol feeding and LPS in WT but not HIF-1alpha(Hep(-/-) ) mice. Using Huh7 hepatoma cells in vitro, we found that MCP-1 treatment induced lipid accumulation and increased HIF-1alpha protein expression as well as DNA-binding activity. Small interfering RNA inhibition of HIF-1alpha prevented MCP-1-induced lipid accumulation, suggesting a mechanistic role for HIF-1alpha in hepatocyte lipid accumulation.

CONCLUSION: Alcohol feeding results in lipid accumulation in hepatocytes involving HIF-1alpha activation. The alcohol-induced chemokine MCP-1 triggers lipid accumulation in hepatocytes via HIF-1alpha activation, suggesting a mechanistic link between inflammation and hepatic steatosis in alcoholic liver disease.

]]> Bharath D. Nath et al. Animals Fatty Liver, Alcoholic Hepatocytes Hypoxia-Inducible Factor 1, alpha Subunit *Lipid Metabolism Mice Long-term correction of very long-chain acyl-coA dehydrogenase deficiency in mice using AAV9 gene therapy http://works.bepress.com/christian_mueller/34 http://works.bepress.com/christian_mueller/34 Wed, 19 Sep 2012 12:30:45 PDT Very long-chain acyl-coA dehydrogenase (VLCAD) is the rate-limiting step in mitochondrial fatty acid oxidation. VLCAD-deficient mice and patients clinical symptoms stem from not only an energy deficiency but also long-chain metabolite accumulations. VLCAD-deficient mice were treated systemically with 1 x 10(12) vector genomes of recombinant adeno-associated virus 9 (rAAV9)-VLCAD. Biochemical correction was observed in vector-treated mice beginning 2 weeks postinjection, as characterized by a significant drop in long-chain fatty acyl accumulates in whole blood after an overnight fast. Changes persisted through the termination point around 20 weeks postinjection. Magnetic resonance spectroscopy (MRS) and tandem mass spectrometry (MS/MS) revealed normalization of intramuscular lipids in treated animals. Correction was not observed in liver tissue extracts, but cardiac muscle extracts showed significant reduction of long-chain metabolites. Disease-specific phenotypes were characterized, including thermoregulation and maintenance of euglycemia after a fasting cold challenge. Internal body temperatures of untreated VLCAD(-/-) mice dropped below 20 degrees C and the mice became lethargic, requiring euthanasia. In contrast, all rAAV9-treated VLCAD(-/-) mice and the wild-type controls maintained body temperatures. rAAV9-treated VLCAD(-/-) mice maintained euglycemia, whereas untreated VLCAD(-/-) mice suffered hypoglycemia following a fasting cold challenge. These promising results suggest rAAV9 gene therapy as a potential treatment for VLCAD deficiency in humans.

]]> Allison M. Keeler et al. Acyl-CoA Dehydrogenase, Long-Chain Dependovirus Gene Therapy Genetic Vectors Lack of CFTR in CD3+ Lymphocytes Leads to Aberrant Cytokine Secretion and Hyper-Inflammatory Adaptive Immune Responses: A Master's Thesis http://works.bepress.com/christian_mueller/33 http://works.bepress.com/christian_mueller/33 Wed, 22 Aug 2012 08:05:46 PDT Background: Cystic fibrosis (CF) remains the most common fatal monogenic disease in the US, affecting 1 in 3,300 live births. CF is the result of mutations in CFTR, a chloride channel and regulator of other ion channels. The mechanisms by which CFTR mutations cause chronic lung disease in CF are not fully defined, but may include the combined effects of altered ion and water transport across the airway epithelium and aberrant inflammatory and immune responses to pathogens within the airways. We have shown that Cftr-/- mice mount an exaggerated IgE response towards Aspergillus fumigatus (Af) when compared to Cftr+/+ mice. Along with the increased IgE levels, the Cftr-/- mice had higher levels of IL-13 and IL-4, mimicking both the Th-2 biased immune responses and predilection to mounting Af-specifc IgE seen in CF patients. Herein we hypothesize that these immune aberrations are primarily due to the lack of Cftr expression in lymphocytes rather than with Cftr deficiency in the epithelium.

Results: Our results indicate that adoptive transfer experiments with Cf splenocytes confer higher IgE response to Af in host mice as compared to hosts receiving wild-type splenocytes. The predilection of Cftr-deficient lymphocytes to mount Th2 responses was confirmed by in vitro antigen recall experiments, where higher levels of IL-13 and IL-4 where seen only in the presence of Cftr-deficient lymphocytes. Conclusive data on this phenomenon were obtained with conditional Cftr knockout mice, where mice lacking Cftr in T-cell lineages developed the higher IgE titers as compared to their wild-type littermate controls. Further analysis of Cftr-deficient lymphocytes revealed an enhanced intracellular Ca 2+ flux in response to T cell receptor activation as compared to normal lymphocytes. This was accompanied by a significant increase in nuclear localization of the calcium-sensitive transcription factor NFAT, which could contribute to the enhanced secretion of IL-13 and other cytokines.

Conclusions: In summary, our data identified that CFTR dysfunction in T cells can lead directly to aberrant immune responses. This is the first instance that a CF related phenotype has been entirely modeled in vivo by selectively knocking out CFTR in the immune system. Specifically, Cftr deficient lymphocytes directed skewed responses to Aspergillus fumigatus , leading to a higher than normal IgE response. These findings implicate the lymphocyte population as a potentially important target for therapeutics directed to the treatment of CF lung disease.

]]> Christian Mueller Cystic Fibrosis Transmembrane Conductance Regulator Theses, UMMS Mutation Lymphocytes Cytokines Antigens, CD3 Immune responses in cystic fibrosis: are they intrinsically defective? http://works.bepress.com/christian_mueller/32 http://works.bepress.com/christian_mueller/32 Thu, 16 Aug 2012 15:46:55 PDT Cystic fibrosis (CF), the most common lethal single-gene disorder affecting Northern Europeans and North Americans, is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Cftr is a chloride channel and a regulator of other ion channels, and many aspects of the CF phenotype are directly related to ion channel abnormalities attributable to CFTR mutation. Lung disease is the most common limitation to the quantity and quality of life for patients with CF. One aspect that continues to be enigmatic is the observed alterations in innate and adaptive immune responses to certain pathogens. Altered responses to Pseudomonas aeruginosa and Aspergillus fumigatus, with an increase in neutrophil chemoattractants in the former case and a hyper-IgE-like state in the latter, are common in CF. Several lines of evidence suggest that the proinflammatory cytokine response to bacterial infection is exaggerated in CF. A literature search reveals that, although the abnormalities in CF immune cells have been recognized since the 1970s, few studies until recently have appreciated the role that CFTR plays in these cell types. A growing body of evidence has emerged that points to neutrophils, macrophages, and T cells as being central to the infectious and pulmonary pathology, accounting for the majority of CF mortality. Primary CFTR defects in T cells are providing new insights into the misorchestration of the CF immune system due to aberrant signaling pathways. Defective CFTR function disrupts the balance of intracellular ion concentrations, including [Ca(2+)], which is known to drive gene expression pathways. New evidence links this hypothesis to anomalies in immune activation observed across CF cell types, which could shed light on the inability of individuals with CF to effectively clear pathogens. This review focuses on the emerging role of Cftr in gene expression and other functions in cells of the innate and adaptive immune system.

]]> Dmitry Ratner et al. Aspergillus fumigatus Cystic Fibrosis Cystic Fibrosis Transmembrane Conductance Regulator Humans Pseudomonas aeruginosa Gene transfer in the lung using recombinant adeno-associated virus http://works.bepress.com/christian_mueller/31 http://works.bepress.com/christian_mueller/31 Tue, 14 Aug 2012 06:30:29 PDT Adeno-associated virus (AAV) is a small replication-deficient DNA virus belonging to the Parvovirinae family. It has a single-stranded ∼4.7-kb genome. Recombinant AAV (rAAV) is created by replacing the viral rep and cap genes with the transgene of interest along with promoter and polyadenylation sequences. The short viral inverted terminal repeats must remain intact for replication and packaging in production, as well as vector genome processing and persistence in the transduction process. The AAV capsid (serotype) determines the tissue tropism of the rAAV vector. In this unit we will discuss serotype selection for lung targeting along with the factors effecting efficient delivery of rAAV vectors to the murine lung. Detailed procedures for lung delivery (intranasal, orotracheal, and surgical tracheal injection), sample collection, and post-mortem tissue processing will be described. Curr. Protoc. Microbiol. 26:14D.2.1-14D.2.17. © 2012 by John Wiley & Sons, Inc.

]]> Alisha Gruntman et al. Gene Therapy Lung Dependovirus Transgenes Gene Transfer Techniques Genetic Vectors rAAV9 airway delivery results in effective knockdown of mutant alpha 1-antitrypsin in the liver while upregulating wildtype alpha 1-antitrypsin in the lung http://works.bepress.com/christian_mueller/30 http://works.bepress.com/christian_mueller/30 Tue, 14 Aug 2012 06:30:27 PDT Alpha 1-Antitrypsin (AAT) deficiency is a human genetic disease resulting in the production of mutant AAT, a hepatocyte produced serine protease inhibitor that functions to prevent alveolar epithelial damage by inhibiting neutrophil elastase. Patients with AAT deficiency have increased lung disease, due to decreased proteolytic protection, as well as sporadic severe liver disease secondary to accumulation of mutant AAT, especially a common mutant form termed PiZ, within hepatocytes. We previously showed, in a PiZ mutant mouse model, simultaneous knock-down of mutant PiZ-AAT and augmentation of wild-type AAT production through intravenous delivery of a recombinant adeno-associated viral (rAAV) vector encoding both a miRNA targeting PiZ-AAT and a miRNA-resistant wild-type AAT gene.

In this study we tested the hypothesis that rAAV2/9 vector administered intra-nasally or intra-tracheally can deliver a gene of interest to both the airways and liver.

Initially C57Bl/6 mice were administered intra-nasally 1011 genome copies (GC) of rAAV2/9 vector expressing a firefly luciferase, which resulted in increased luminescence in the nasal passages, liver, and lung 21 days post delivery. Next, 1012 GC of rAAV2/9 vector expressing GFP and miRNAs targeting PiZ-AAT were delivered via oro-tracheal intubation to PiZ mice. This resulted in decreased serum AAT levels in the PiZ mice and GFP expression in both the liver and lungs. Finally, 1012 GC of rAAV2/9 vector encoding miRNA resistant wild-type AAT and miRNAs targeting PiZ-AAT were delivered via oro-tracheal intubation. This resulted in both systemic and local (liver and lung) elevations in wild-type AAT as well as decreased PiZ-AAT levels.

In conclusion, tracheal delivery of rAAV2/9 resulted in expression of AAT in the liver and lung of treated animals, with sufficient targeting of the liver to mediate knock-down of mutant AAT to a similar degree as intravenous delivery, representing a potential non-invasive delivery route for gene therapy in AAT deficient patients.

]]> Alisha Gruntman et al. alpha 1-Antitrypsin Deficiency Gene Therapy Gene Transfer Techniques Genetic Vectors Production and discovery of novel recombinant adeno-associated viral vectors http://works.bepress.com/christian_mueller/29 http://works.bepress.com/christian_mueller/29 Tue, 14 Aug 2012 06:30:24 PDT In this unit, we describe the detailed procedure for a three-plasmid transfection method for rAAV production, and discuss its advantages, limitations, and troubleshooting techniques. We further discuss the rAAV purification process using CsCl gradients, as well as subsequent quality control methods using SDS-PAGE and real-time PCR to assess vector purity, packaging efficiency, and viral titer. Finally, we elaborate on a PCR-based strategy that can be used to discover novel AAV capsid sequences from primate tissue, which can be used to develop newer-generation rAAVs with a greater diversity of tissue tropism for clinical gene therapy. Curr. Protoc. Microbiol. 26:14D.1.1-14D.1.21. © 2012 by John Wiley & Sons, Inc.

]]> Christian Mueller et al. Gene Therapy Dependovirus Genetic Vectors Codon Optimization for Alpha 1-Antitrypsin Disease http://works.bepress.com/christian_mueller/28 http://works.bepress.com/christian_mueller/28 Tue, 22 May 2012 07:29:54 PDT Alpha 1-antitrypsin deficiency is a genetic disorder caused by defective production of alpha 1-antitrypsin (AAT). Gene therapy approaches have been conducted in patients with AAT deficiency with successful AAT expression, but not to the therapeutic levels required to reduce the risk of emphysema. Codon optimization, a somewhat new and evolving technique, is used by many scientists to maximize protein expression in living organisms by altering translational and transcriptional efficiency as well as protein refolding. The purpose of this study was to develop single stranded and double stranded AAT gene constructs, test their protein expression in vitro, and compare with those levels expressed by the AAT construct that is currently in clinical trials. Three constructs were to be developed, yet only one construct was successfully cloned. This clone, optimized ds-CB-AAT, illustrated increased AAT protein expression as the transfection time increased. However, protein levels were appreciably lower in the optimized construct compared to the single stranded (long intron) AAT construct that is currently being administered in clinical trials. The data did not suggest that the optimized AAT construct does in fact express more AAT protein in vitro as expected. In order to achieve data that can be reproduced, the 2 remaining constructs need to be cloned and all of the isolated plasmid DNA should be prepared on the same scale to minimize any additional confounding variables.

]]> Timothy Menz et al. alpha 1-Antitrypsin Deficiency Effects of CFTR, interleukin-10, and Pseudomonas aeruginosa on gene expression profiles in a CF bronchial epithelial cell Line http://works.bepress.com/christian_mueller/27 http://works.bepress.com/christian_mueller/27 Tue, 06 Mar 2012 05:32:22 PST Mutations in CFTR lead to a complex phenotype that includes increased susceptibility to Pseudomonas infections, a functional deficiency of IL-10, and an exaggerated proinflammatory cytokine response. We examined the effects of CFTR gene correction on the gene expression profile of a CF bronchial epithelial cell line (IB3-1) and determined which CF-related gene expression changes could be reversed by IL-10 expression. We performed microarray experiments to monitor the gene expression profile of three cell lines over a time course of exposure to Pseudomonas. At baseline, we identified 843 genes with statistically different levels of expression in CFTR-corrected (S9) cells compared to the IB3-1 line or the IL-10-expressing line. K-means clustering and functional group analysis revealed a primary up-regulation of ubiquitination enzymes and TNF pathway components and a primary down-regulation of protease inhibitors and protein glycosylation enzymes in CF. Key gene expression changes were confirmed by real-time RT-PCR. Massive reprogramming of gene expression occurred 3 h after Pseudomonas exposure. Changes specific to CF included exaggerated activation of cytokines, blunted activation of anti-proteases, and repression of protein glycosylation enzymes. In conclusion, the CFTR genotype changes the expression of multiple genes at baseline and in response to bacterial challenge, and only a subset of these changes is secondary to IL-10 deficiency.

]]> Isabel Virella-Lowell et al. Cystic Fibrosis Pseudomonas aeruginosa Functional characterization of a recombinant adeno-associated virus 5-pseudotyped cystic fibrosis transmembrane conductance regulator vector http://works.bepress.com/christian_mueller/26 http://works.bepress.com/christian_mueller/26 Tue, 06 Mar 2012 05:32:21 PST Despite extensive experience with recombinant adeno-associated virus (rAAV) 2 vectors in the lung, gene expression has been low in the context of cystic fibrosis (CF) gene therapy, where the large size of the cystic fibrosis transmembrane conductance regulator (CFTR) coding sequence has prompted the use of compact endogenous promoter elements. We evaluated the possibility that gene expression from recombinant adeno-associated virus (rAAV) could be improved by using alternate AAV capsid serotypes that target different cell-surface receptors (i.e., rAAV5) and/or using stronger promoters. The relative activities of the cytomegalovirus (CMV) Rous sarcoma virus (RSV) promoter, the CMV enhancer/beta-actin (CB) promoter combination, and the CMV enhancer/RSV promoter hybrid were assessed in vitro in a CF bronchial cell line. The CB promoter was the most efficient. AAV capsid serotypes, rAAV2 and rAAV5, were also compared, and rAAV5 was found to be significantly more efficient. Based on these studies a rAAV5-CB-promoter-driven CFTR minigene vector was then used to correct the CF chloride transport defect in vitro, as well as the hyperinflammatory lung phenotype in Pseudomonas-agarose bead challenged CF mouse lungs in vivo. These studies provide functional characterization of a new version of rAAV-CFTR vectors.

]]> Jeffrey Sirninger et al. Cystic Fibrosis Gene Therapy Pseudomonas aeruginosa Cystic fibrosis transmembrane conductance regulator deficiency exacerbates islet cell dysfunction after beta-cell injury http://works.bepress.com/christian_mueller/25 http://works.bepress.com/christian_mueller/25 Tue, 06 Mar 2012 05:32:19 PST The cause of cystic fibrosis-related diabetes (CFRD) remains unknown, but cystic fibrosis transmembrane conductance regulator (CFTR) mutations contribute directly to multiple aspects of the cystic fibrosis phenotype. We hypothesized that susceptibility to islet dysfunction in cystic fibrosis is determined by the lack of functional CFTR. To address this, glycemia was assessed in CFTR null (CFTR(-/-)), C57BL/6J, and FVB/NJ mice after streptozotocin (STZ)-induced beta-cell injury. Fasting blood glucose levels were similar among age-matched non-STZ-administered animals, but they were significantly higher in CFTR(-/-) mice 4 weeks after STZ administration (288.4 +/- 97.4, 168.4 +/- 35.9, and 188.0 +/- 42.3 mg/dl for CFTR(-/-), C57BL/6J, and FVB/NJ, respectively; P < 0.05). After intraperitoneal glucose administration, elevated blood glucose levels were also observed in STZ-administered CFTR(-/-) mice. STZ reduced islets among all strains; however, only CFTR(-/-) mice demonstrated a negative correlation between islet number and fasting blood glucose (P = 0.02). To determine whether a second alteration associated with cystic fibrosis (i.e., airway inflammation) could impact glucose control, animals were challenged with Aspergillus fumigatus. The A. fumigatus-sensitized CFTR(-/-) mice demonstrated similar fasting and stimulated glucose responses in comparison to nonsensitized animals. These studies suggest metabolic derangements in CFRD originate from an islet dysfunction inherent to the CFTR(-/-) state.

]]> Michael S. Stalvey et al. Cystic Fibrosis Enhanced IgE allergic response to Aspergillus fumigatus in CFTR-/- mice http://works.bepress.com/christian_mueller/24 http://works.bepress.com/christian_mueller/24 Tue, 06 Mar 2012 05:32:17 PST To gain insight into aberrant cytokine regulation in cystic fibrosis (CF), we compared the phenotypic manifestations of allergen challenge in gut-corrected CFTR-deficient mice with background-matched C57Bl6 (B6) mice. Aspergillus fumigatus (Af) antigen was used to mimic allergic bronchopulmonary aspergillosis, a peculiar hyper-IgE syndrome with a high prevalence in CF patients. CFTR-/-, C57BL/6 and FVB/NJ mice were sensitized with Af antigen by serial intraperitoneal injections. Control mice were mock sensitized with PBS. Challenges were performed by inhalation of Af antigen aerosol. After Af antigen challenge, histologic analysis showed goblet cell hyperplasia and lymphocytic infiltration in both strains. However, total serum IgE levels were markedly elevated in CF mice. Sensitized CF mice showed a five-fold greater IgE response to sensitization as compared with B6- and FVB-sensitized controls. Additional littermate controls to fully normalize for B6-FVB admixture in the strain background confirmed the role of CFTR mutation in the hyper-IgE syndrome. Cytokine mRNA levels of IL-5 and GM-CSF in the bronchoalveolar lavage (BAL) fluid, and BAL cell differentials indicated that CFTR mutation caused a shift from an IL-5-predominant to an IL-4-predominant cytokine profile. This system models a very specific type of airway inflammation in CF and could provide insights into pathogenesis and treatment of the disease.

]]> Christian Mueller et al. Cystic Fibrosis Aspergillus fumigatus Cystic Fibrosis http://works.bepress.com/christian_mueller/23 http://works.bepress.com/christian_mueller/23 Mon, 05 Mar 2012 08:54:05 PST Citation: Stalvey, M., Mueller, C., and Flotte, T. “Cystic Fibrosis”, in Domino FJ, ed., The 5-Minute Clinical Consult 2011. Lippincott Williams & Wilkins, 19th Edition, p. 340-341, 2010.

A preview of this chapter is available via Google Books.

]]> Michael S. Stalvey et al. Cystic Fibrosis CFTR mutations impart elevated immune reactivity in a murine model of cystic fibrosis related diabetes http://works.bepress.com/christian_mueller/22 http://works.bepress.com/christian_mueller/22 Sat, 03 Mar 2012 12:20:25 PST Increased life expectancy in cystic fibrosis (CF) is accompanied by an increasing incidence of CF related diabetes (CFRD). Altered immune reactivity occurs in CF, which we hypothesize, is exacerbated by hyperglycemia. Cystic fibrosis transmembrane conductance regulator deficient (CFTR-/-) mice were rendered hyperglycemic by streptozotocin (STZ) to test this hypothesis. CFTR-/-, C57BL/6J, and FVB/NJ mice received either STZ or lactated ringers (LR) (n=5-10). Four weeks later, splenocytes were harvested, mitogen stimulated, and analyzed for cytokine production (IL-2, IL-4, and IL-10) along with stimulation indices (SI). SI of STZ-treated CFTR-/- were elevated compared to LR-treated mice, although both were greater than C57BL/6J and FVB/NJ (p<0.05). Fasting glucose levels of STZ-treated CFTR-/- mice correlated with SI (p<0.003). Stimulated IL-10 concentrations were elevated in STZ-treated CFTR-/- compared to LR-treated animals and controls (p<0.05). IL-2 levels were greater in CFTR-/- mice compared to controls (p<0.05), but unrelated to STZ. Reinforcing generalized cytokine up-regulation in CFTR-/-, IL-4 levels were greater in CFTR-/- mice compared to C57BL/6J, but FVB/NJ mice demonstrated greatest concentrations following STZ. These results suggest that, hyperglycemia may exacerbate the clinical course in CF by impacting immune reactivity. There is clear need to maximize metabolic management in CFRD.

]]> Michael S. Stalvey et al. Cystic Fibrosis Phase 2 clinical trial of a recombinant adeno-associated viral vector expressing α1-antitrypsin: interim results http://works.bepress.com/christian_mueller/21 http://works.bepress.com/christian_mueller/21 Sat, 03 Mar 2012 12:20:23 PST Recombinant adeno-associated virus (rAAV) vectors offer promise for the gene therapy of α(1)-antitrypsin (AAT) deficiency. In our prior trial, an rAAV vector expressing human AAT (rAAV1-CB-hAAT) provided sustained, vector-derived AAT expression for >1 year. In the current phase 2 clinical trial, this same vector, produced by a herpes simplex virus complementation method, was administered to nine AAT-deficient individuals by intramuscular injection at doses of 6.0×10(11), 1.9×10(12), and 6.0×10(12) vector genomes/kg (n=3 subjects/dose). Vector-derived expression of normal (M-type) AAT in serum was dose dependent, peaked on day 30, and persisted for at least 90 days. Vector administration was well tolerated, with only mild injection site reactions and no serious adverse events. Serum creatine kinase was transiently elevated on day 30 in five of six subjects in the two higher dose groups and normalized by day 45. As expected, all subjects developed anti-AAV antibodies and interferon-γ enzyme-linked immunospot responses to AAV peptides, and no subjects developed antibodies to AAT. One subject in the mid-dose group developed T cell responses to a single AAT peptide unassociated with any clinical effects. Muscle biopsies obtained on day 90 showed strong immunostaining for AAT and moderate to marked inflammatory cell infiltrates composed primarily of CD3-reactive T lymphocytes that were primarily of the CD8(+) subtype. These results support the feasibility and safety of AAV gene therapy for AAT deficiency, and indicate that serum levels of vector-derived normal human AAT >20 μg/ml can be achieved. However, further improvements in the design or delivery of rAAV-AAT vectors will be required to achieve therapeutic target serum AAT concentrations.

]]> Terence R. Flotte et al. Gene Therapy alpha 1-Antitrypsin Deficiency The pros and cons of immunomodulatory IL-10 gene therapy with recombinant AAV in a Cftr-/- -dependent allergy mouse model http://works.bepress.com/christian_mueller/20 http://works.bepress.com/christian_mueller/20 Sat, 03 Mar 2012 12:20:21 PST Cystic fibrosis (CF) patients have decreased levels of lung epithelial interleukin (IL)-10 and increased levels of proinflammatory cytokines (tumor necrosis factor-alpha, IL-4, IL-8 and IL-6). This has also been documented in Cftr (cystic fibrosis transmembrane conductance regulator)-deficient mice (Cftr 489X(-/-), FABP-hCFTR(+/+)). Our laboratory has recently characterized a peculiar hyper-IgE phenotype in these mice, in response to Aspergillus fumigatus crude protein extract (Af-cpe). Thus, we hypothesized that sustained systemic circulating IL-10 levels achieved through skeletal muscle transduction with recombinant adeno-associated vectors expressing IL-10 (rAAV1-IL-10) would serve to downregulate Th1 and Th2 cytokine production. This in turn would dampen the allergic response in the Cftr(-/-)-dependent mouse model of allergic bronchopulmonary aspergillosis. After Af-cpe sensitization and airway challenge, mice treated with rAAV1-IL-10 had markedly lower IgE levels when compared to the control-treated rAAV1-GFP group. This was accompanied by a significant reduction in the levels of IL-5, IL-4 and IL-13 in the lung compartment. The lower lung cytokine profiles resulted in a near absence of eosinophil recruitment in the lung and a lower inflammatory response in the lung tissue of mice receiving rAAV1-IL-10. Unfortunately, sustained secretion of IL-10 from transduced muscle did lead to thrombocytopenia and splenomegaly in mice injected with rAAV1-IL-10. These results highlight that while IL-10 gene therapy is very effective for treating allergic responses caution must be taken with the prolonged secretion of IL-10.

]]> Christian Mueller et al. Cystic Fibrosis Gene Therapy Aspergillus fumigatus Apparently nonspecific enzyme elevations after portal vein delivery of recombinant adeno-associated virus serotype 2 vector in hepatitis C virus-infected chimpanzees http://works.bepress.com/christian_mueller/19 http://works.bepress.com/christian_mueller/19 Sat, 03 Mar 2012 12:20:20 PST Hepatic gene transfer is envisioned as a substitute for protein replacement therapies, many of which are derived from blood products. Thus, the target populations may have a high prevalence of blood-borne pathogens, such as hepatitis C virus (HCV). We sought to determine whether the safety of recombinant adeno-associated virus serotype 2 (rAAV2) would be altered by preexisting HCV infection. Doses of approximately 1 x 10(13) vector genomes of an rAAV2-chimpanzee alpha(1)-antitrypsin (rAAV2-cAAT) vector were injected into the portal vein of each of three HCV genome-positive (HCV+) chimpanzees and three HCV-negative (HCV-) controls. Acute safety studies were performed up to 90 days after vector administration, along with analyses of the peripheral blood and liver tissue for rAAV2-cAAT genomes. Vector genome copy numbers in blood and liver tissue were similar in both groups. All animals demonstrated increases in liver and muscle enzyme levels after the pretreatment liver biopsy (5 days before vector injection) and after the vector injection. However, HCV+ animals demonstrated a substantially greater rise in aspartate aminotransferase, alanine aminotransferase, and creatinine phosphokinase values than HCV- animals. Histopathology demonstrated abnormal lipid accumulation (steatosis) in the hepatocytes of HCV+ animals, both before and after vector injection. These data indicate an increased susceptibility to subclinical liver toxicity from portal vein injection of rAAV2 in the presence of HCV infection.

]]> Terence R. Flotte et al. Gene Therapy Clinical gene therapy using recombinant adeno-associated virus vectors http://works.bepress.com/christian_mueller/18 http://works.bepress.com/christian_mueller/18 Sat, 03 Mar 2012 12:20:18 PST Recombinant adeno-associated virus (rAAV) vectors possess a number of properties that may make them suitable for clinical gene therapy, including being based upon a virus for which there is no known pathology and a natural propensity to persist in human cells. Wild-type adeno-associated viruses (AAVs) are now known to be very diverse and ubiquitous in humans and nonhuman primates, which adds to the degree of confidence one may place in the natural history of AAV, namely that it has never been associated with any human tumors or other acute pathology, other than sporadic reports of having been isolated from spontaneously aborted fetuses. On the basis of this understanding of AAV biology and a wide range of preclinical studies in mice, rabbits, dogs and nonhuman primates, a growing number of clinical trials have been undertaken with this class of vectors. Altogether, over 40 clinical trials have now been approved. Although all previous trials were undertaken using AAV serotype 2 vectors, at least two current trials utilize AAV2 vector genomes cross-packaged or pseudotyped into AAV1 capsids, which appear to mediate more efficient gene delivery to muscle. The explosion of capsid isolates available for use as vectors to over 120 has now provided the potential to broaden the application of AAV-based gene therapy to other cell types.

]]> Christian Mueller et al. Gene Therapy Induction of Group IVC Phospholipase A2 in Allergic Asthma: Transcriptional Regulation by TNF-α in Bronchoepithelial Cells http://works.bepress.com/christian_mueller/16 http://works.bepress.com/christian_mueller/16 Sat, 03 Mar 2012 12:20:15 PST Airway inflammation in allergen-induced asthma is associated with eicosanoid release. These bioactive lipids exhibit anti- and pro-inflammatory activities with relevance to pulmonary pathophysiology. We hypothesized that sensitization/challenge using an extract from the ubiquitous fungus, Aspergillus fumigatus (Af), in a mouse model of allergic asthma would result in altered phospholipase gene expression, thus modulating the downstream eicosanoid pathway. We observed the most significant induction in the group IVC phospholipase A2 (cPLA2γ or PLA2G4C). Our results infer that Af extract can induce cPLA2γ levels directly in eosinophils while induction in lung epithelial cells is most likely a consequence of TNF-α secretion by Af-activated macrophages. The mechanism of TNF-α-dependent induction of cPLA2γ gene expression was elucidated through a combination of promoter deletions, ChIP and overexpression studies in human bronchoepithelial cells, leading to the identification of functionally relevant CRE, NF-κB and E-box promoter elements. ChIP analysis demonstrated that RNA polymerase II, c-Jun/ATF-2, p65/p65 and USF1/USF2 complexes are recruited to the cPLA2γ enhancer/promoter in response to TNF-α with overexpression and dominant negative studies implying a strong level of cooperation and interplay between these factors. Overall, our data link cytokine-mediated alterations in cPLA2γ gene expression with allergic asthma and outline a complex regulatory mechanism.

]]> Justin S. Bickford et al. Cystic Fibrosis Partial correction of the CFTR-dependent ABPA mouse model with recombinant adeno-associated virus gene transfer of truncated CFTR gene http://works.bepress.com/christian_mueller/15 http://works.bepress.com/christian_mueller/15 Sat, 03 Mar 2012 12:20:13 PST Recently, we have developed a model of airway inflammation in a CFTR knockout mouse utilizing Aspergillus fumigatus crude protein extract (Af-cpe) to mimic allergic bronchopulmonary aspergillosis (ABPA) 1, an unusual IgE-mediated hypersensitivity syndrome seen in up to 15% of cystic fibrosis (CF) patients and rarely elsewhere. We hypothesized that replacement of CFTR via targeted gene delivery to airway epithelium would correct aberrant epithelial cytokine signaling and ameliorate the ABPA phenotype in CFTR-deficient (CFTR 489X - /-, FABP-hCFTR + / +) mice. CFTR knockout mice underwent intra-tracheal (IT) delivery of recombinant adeno-associated virus serotype 5 (rAAV5Delta-264CFTR) or rAAV5-GFP at 2.58 x 10(12) viral genomes/mouse. All mice were then sensitized with two serial injections (200 microg) of crude Af antigen via the intra-peritoneal (IP) route. Untreated mice were sensitized without virus exposure. Challenges were performed 2 weeks after final sensitization, using a 0.25% solution containing Aspergillus fumigatus crude protein extract delivered by inhalation on three consecutive days. The rAAV5Delta-264CFTR-treated mice had lower total serum IgE levels (172513 ng/ml +/- 1312) than rAAV5-GFP controls (26 892 ng/ml +/- 3715) (p = 0.037) and non-treated, sensitized controls (24 816 +/- 4219 ng/ml). Serum IgG1 levels also were lower in mice receiving the CFTR vector. Interestingly, splenocytes from rAAV5Delta-264CFTR-treated mice secreted less IL-13, INFg, TNFa, RANTES and GM-CSF after ConA stimulation. Gene therapy with rAAV5Delta-264CFTR attenuated the hyper-IgE response in this reproducible CF mouse model of ABPA, with systemic effects also evident in the cytokine response of stimulated splenocytes.

]]> Christian Mueller et al. Aspergillus fumigatus