76
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Kaplan JM, Armentano D, Sparer TE, Wynn SG, Peterson PA, Wadsworth SC, Couture KK, Pennington SE, St George JA, Gooding LR, Smith AE. Characterization of factors involved in modulating persistence of transgene expression from recombinant adenovirus in the mouse lung. Hum Gene Ther 1997; 8:45-56. [PMID: 8989994 DOI: 10.1089/hum.1997.8.1-45] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
One potential limitation of adenovirus (Ad)-based vectors for the gene therapy of cystic fibrosis (CF) and other genetic diseases is the transience of expression observed in most in vivo systems. In this study, the influence of various factors on persistence of transgene expression in the lung was investigated. In the absence of immune pressure, such as in the nude mouse, the genomic structure of the vector was found to be predominant in determining the persistence of expression; Ad vector constructs with an E1-E3+E4ORF6+ backbone encoding beta-galactosidase (beta-Gal) or the cystic fibrosis transmembrane conductance regulator (CFTR) produced declining levels of expression while an Ad/CMV beta Gal vector with an E1-E3+E4+ backbone gave rise to sustained, long-term reporter gene expression. The ability of the latter vector to persist was in turn limited in part by the presence of cytotoxic T lymphocytes (CTLs). Adoptive transfer experiments indicated that CTLs directed against either viral proteins or the beta-Gal reporter gene product were able to reduce expression in nude C57BL/6 mice stably expressing beta-Gal from the E4+ vector. Finally, the specificity and strength of the CTL response elicited by Ad vector was found to vary considerably depending on mouse strain haplotype. These results indicate that persistence of transgene expression in a given system is determined by the interplay between several factors including genomic structure of the vector, host background, and immune response.
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77
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Kilmer RA, Smith AE, Shuman LJ. An emergency department simulation and a neural network metamodel. JOURNAL OF THE SOCIETY FOR HEALTH SYSTEMS 1997; 5:63-79. [PMID: 9035024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This paper describes a discrete event stochastic simulation of a hospital emergency department, and the development of a metamodel of that simulation. The metamodeling technique used is artificial neural networks, which are trained utilizing the output of the simulation. The performance of the neural network metamodel is compared to the simulation performance for estimating the mean and variance of patient time in the emergency department.
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78
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Toida T, Hileman RE, Smith AE, Vlahova PI, Linhardt RJ. Enzymatic preparation of heparin oligosaccharides containing antithrombin III binding sites. J Biol Chem 1996; 271:32040-7. [PMID: 8943254 DOI: 10.1074/jbc.271.50.32040] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Two new oligosaccharides were prepared from heparin by its partial depolymerization using heparin lyase I (EC 4.2.2.7) in an attempt to prepare oligosaccharides having intact antithrombin III binding sites. The oligosaccharides were purified by chromatography on the basis of both size and charge and demonstrated a high level of purity by capillary electrophoresis. One- and two-dimensional 1H NMR spectroscopy at 500 MHz revealed the structure of each oligosaccharide. The octasaccharide and decasaccharide are DeltaUAp2S(1-->4)-alpha-DGlcNpS6S(1-->4)-alpha-L-IdoAp (1-->4)-alpha-D -GlcNpAc6S(1-->4)-betaD-GlcAp(1-->4)-alpha-D-GlcNpS 3S6S(1-->4)-alpha- L-IdoAp2S(1-->4)alpha-D-GlcNpS6S (where DeltaUAp is 4-deoxy-alpha-L-threo-hex-enopyranosyluronic acid, GlcNp is 2-amino-2-deoxy-glucopyranose, GlcAp is glucopyranosyluronic acid, S is sulfate and Ac is acetate) and DeltaUAp2S(1-->4)-alpha-D-GlcNpS6S(1-->4)-alpha-L-IdoAp++ +(1-->4)-alpha- D-GlcNpAc6S (1-->4)-beta-D-GlcAp(1-->4)-alpha-D-GlcNpS3S6S(1-->4)-alpha- L-IdoAp2S (1-->4)-alpha-D-GlcNpS6S(1-->4)-alpha-L-IdoAp2S(1-->4)-alpha -D-GlcNpS 6S, respectively. A hexasaccharide containing a similar structural motif to that found in the antithrombin III binding site and having greatly reduced anticoagulant activity was also isolated. The structure of the hexasaccharide is DeltaUAp2S(1-->4)-alpha-D-GlcNpAc6S(1-->4)-beta-D-GlcAp++ +(1-->4)-alpha- D-GlcNpS3S6S(1-->4)-alpha-L-IdoAp(1-->4)-alpha-D-GlcNpS6S . The octasaccharide and decasaccharide correspond to the predominant structural motif found in porcine intestinal mucosal heparin. Sufficient quantities of the decasaccharide were obtained to examine its interaction with antithrombin III using microtitration calorimetry. This decasaccharide bound to antithrombin III with similar avidity as heparin and showed comparable anticoagulant activity, as determined using an antithrombin III dependent anti-factor Xa assay. Interestingly, while both decasaccharide and heparin bound to antithrombin with nanomolar affinity, very little heat of binding was observed.
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79
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Hehir KM, Armentano D, Cardoza LM, Choquette TL, Berthelette PB, White GA, Couture LA, Everton MB, Keegan J, Martin JM, Pratt DA, Smith MP, Smith AE, Wadsworth SC. Molecular characterization of replication-competent variants of adenovirus vectors and genome modifications to prevent their occurrence. J Virol 1996; 70:8459-67. [PMID: 8970968 PMCID: PMC190936 DOI: 10.1128/jvi.70.12.8459-8467.1996] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Adenovirus (Ad) vectors for gene therapy are made replication defective by deletion of E1 region genes. For isolation, propagation, and large-scale production of such vectors, E1 functions are supplied in trans from a stable cell line. Virtually all Ad vectors used for clinical studies are produced in the 293 cell, a human embryonic kidney cell line expressing E1 functions from an integrated segment of the left end of the Ad type 5 (Ad5) genome. Replication-competent vector variants that have regained E1 sequences have been observed within populations of Ad vectors grown on 293 cells. These replication-competent variants presumably result from recombination between vector and 293 cell Ad5 sequences. We have developed Ad2-based vectors and have characterized at the molecular level examples of replication-competent variants. All such variants analyzed are Ad2-Ad5 chimeras in which the 293 cell Ad5 E1 sequences have become incorporated into the viral genome by legitimate recombination events. A map of Ad5 sequences within the 293 cell genome developed in parallel is consistent with the proposed recombination events. To provide a convenient vector production system that circumvents the generation of replication-competent variants, we have modified the Ad2 vector backbone by deleting or rearranging the protein IX coding region normally present downstream from the E1 region such that the frequency of recombination between vector and 293 cell Ad5 sequences is greatly reduced. Twelve serial passages of an Ad2 vector lacking the protein IX gene were carried out without generating replication-competent variants. In the course of producing and testing more than 30 large-scale preparations of vectors lacking the protein IX gene or having a rearranged protein IX gene, only three examples of replication-competent variants were observed. Use of these genome modifications allows use of conventional 293 cells for production of large-scale preparations of Ad-based vectors lacking replication-competent variants.
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80
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Forsyth AJ, Josefsson TW, Smith AE. Dielectric-matrix calculation of the volume-plasmon dispersion relation for silicon. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:14355-14361. [PMID: 9985441 DOI: 10.1103/physrevb.54.14355] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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81
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Jiang C, O'Connor SP, Armentano D, Berthelette PB, Schiavi SC, Jefferson DM, Smith AE, Wadsworth SC, Cheng SH. Ability of adenovirus vectors containing different CFTR transcriptional cassettes to correct ion transport defects in CF cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1996; 271:L527-37. [PMID: 8897899 DOI: 10.1152/ajplung.1996.271.4.l527] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cystic fibrosis (CF) airway epithelial cells exhibit defective adenosine 3',5'-cyclic monophosphate (cAMP)-mediated chloride (Cl) secretion, abnormal hyperabsorption of sodium (Na+), and aberrant fluid transport. Adenovirus-mediated transduction of cystic fibrosis transmembrane conductance regulator (CFTR) corrects these ion and fluid transport abnormalities in CF cells. However, several challenges remain pertaining to the use of adenovirus vectors for gene delivery, including the efficiency of gene transfer and the host response to the vector. To improve the efficacy of adenovirus-mediated gene transfer, we have constructed a series of recombinant adenoviruses containing different CFTR transcriptional units, and we have evaluated their relative ability to correct electrolyte and fluid transport in polarized CF airway epithelial cells. The ability of the vectors to correct the CF Cl- transport defects was greatest when the human cytomegalovirus promoter was used. The E1a and phosphoglycerate kinase promoters resulted in the greatest persistence of functional CFTR expression. Efficacy of gene expression by recombinant adenoviruses improved as the cells were treated with increasing multiplicities of infection, as the duration of viral contact with the target cells was lengthened, and when the virus concentration was increased. Transduction of functional CFTR Cl- channel activity reversed the abnormal Na+ hyperabsorption observed in CF cells in a dose-dependent manner, suggesting that Na+ channel activity is downregulated by CFTR. Although efficient correction of both cAMP-mediated Cl- transport and fluid secretion could be achieved readily with these vectors, normalization of the Na+ absorption required vector administration at high multiplicities of infection.
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82
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Lee ER, Marshall J, Siegel CS, Jiang C, Yew NS, Nichols MR, Nietupski JB, Ziegler RJ, Lane MB, Wang KX, Wan NC, Scheule RK, Harris DJ, Smith AE, Cheng SH. Detailed analysis of structures and formulations of cationic lipids for efficient gene transfer to the lung. Hum Gene Ther 1996; 7:1701-17. [PMID: 8886841 DOI: 10.1089/hum.1996.7.14-1701] [Citation(s) in RCA: 335] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Cationic lipid-mediated gene transfer of cystic fibrosis transmembrane conductance regulator (CFTR) cDNA represents a promising approach for treatment of cystic fibrosis (CF). Here, we report on the structures of several novel cationic lipids that are effective for gene delivery to the lungs of mice. An amphiphile (#67) consisting of a cholesterol anchor linked to a spermine headgroup in a "T-shape" configuration was shown to be particularly efficacious. An optimized formulation of #67 and plasmid vector encoding chloramphenicol acetyl-transferase (CAT) was capable of generating up to 1 microgram of CAT enzyme/lung following intranasal instillation into BALB/c mice. This represents a 1,000-fold increase in expression above that obtained in animals instilled with naked pDNA alone and is greater than 100-fold more active than cationic lipids used previously for CFTR gene expression. When directly compared with adenovirus-based vectors containing similar transcription units, the number of molecules of gene product expressed using lipid-mediated transfer was equivalent to vector administration at multiplicities of infection ranging from 1 to 20. The level of transgene expression in the lungs of BALB/c mice peaked between days 1 and 4 post-instillation, followed by a rapid decline to approximately 20% of the maximal value by day 7. Undiminished levels of transgene expression in the lung could be obtained following repeated intranasal administration of #67:DOPE:pCF1-CAT in nude mice. Transfection of cells with formulations of #67:DOPE:pCF1-CFTR generated cAMP-stimulated CFTR chloride channel and fluid transport activities, two well-characterized defects associated with CF cells. Taken together, the data demonstrate that cationic lipid-mediated gene delivery and expression of CFTR in CF lungs is a viable and promising approach for treatment of the disease.
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83
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Murphy S, Turner G, Piper T, Roberts B, Wadworth S, Smith AE, Wells DJ, Dickson G. Adenoviral vectors for gene transfer of full-length human dystrophin cDNAs. Biochem Soc Trans 1996; 24:277S. [PMID: 8736935 DOI: 10.1042/bst024277s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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84
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Zabner J, Wadsworth SC, Smith AE, Welsh MJ. Adenovirus-mediated generation of cAMP-stimulated Cl- transport in cystic fibrosis airway epithelia in vitro: effect of promoter and administration method. Gene Ther 1996; 3:458-65. [PMID: 9156806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Cystic fibrosis (CF) is a common autosomal recesses disease in which loss of CFTR-Cl- channel function of defective cAMP-stimulated Cl- transport transfer across airway epithelia. Recombinant adenoviruses have shown progress as vectors with which to transfer CFTR cDNA to CF airway epithelia. Here we investigated variables involved in adenovirus-mediated transfer of CFTR by measuring cAMP- stimulated Cl- transport in CF airway epithelia grown as monolayers on permeable filter supports. When we compared the effects of different promoters, we found that persistent correction of Cl- transport was obtained when the vector contained the E1a promoter, or to a lesser extent the PGK promoter. Vector containing the CMV promoter produced a greater initial cAMP-stimulated Cl- current, but the duration of correction was shorter and the infection procedure itself increased CFTR expression, suggesting that high input doses of virus stimulate expression. We compared the level of expression, measured with a beta-galactosidase reporter of CFTR mRNA, with CFTR-mediated Cl- transport. Even low levels of expression generated significant Cl- current and marked increases in expression produced only modest increments in Cl- current. Correction of the CF Cl- transport defect was also improved when the concentration of adenovirus vector was high and when the duration of contact with the epithelium was prolonged. These findings may help optimize the ability of adenovirus vectors encoding CFTR to correct the CF Cl- transport defect.
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85
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Smith AE. Medicine and public health initiative. THE JOURNAL OF THE FLORIDA MEDICAL ASSOCIATION 1996; 83:295-6. [PMID: 8666964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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86
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Smith AE. The patients' demand trust: quality and consumer information. THE JOURNAL OF THE FLORIDA MEDICAL ASSOCIATION 1996; 83:159-60. [PMID: 8920044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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87
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Kaplan JM, St George JA, Pennington SE, Keyes LD, Johnson RP, Wadsworth SC, Smith AE. Humoral and cellular immune responses of nonhuman primates to long-term repeated lung exposure to Ad2/CFTR-2. Gene Ther 1996; 3:117-27. [PMID: 8867859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
To evaluate the host immune response to long-term repeat administration of adenovirus vector, rhesus monkeys were treated at intervals of approximately 3 weeks with up to 18 instillations of Ad2/CFTR-2, a second generation vector encoding the cystic fibrosis transmembrane conductance regulator (CFTR). All monkeys instilled with Ad2/CFTR-2 developed a significant humoral immune response against adenovirus but not CFTR. Antibodies with virus neutralizing activity were detected in the serum and bronchoalveolar lavage (BAL) of all vector-treated monkeys and included both IgG and secretory IgA. Virus-specific T cells capable of proliferating in response to stimulation with adenovirus antigen were detected in all vector-treated monkeys. No CFTR-specific proliferation of peripheral blood lymphocytes was detected. An increase in the proportion of CD8+ T cells was noted in the BAL of virus-treated monkeys but cells from the BAL displayed little or no cytolytic activity against infected autologous fibroblasts when tested under a variety of culture conditions. However, MHC-restricted cytolytic activity was detected in the tracheobronchial lymph nodes and spleen of one of three virus-treated monkeys tested. MHC-unrestricted killing of infected fibroblasts was also observed with spleen cells from all animals tested. From these results, it appears that both the humoral and cell-mediated arms of the immune response were stimulated by repeated administration of high doses of Ad2/CFTR-2 suggesting that effective, long-term adenovirus gene therapy may require modification of the vector or treatment of the host to allow the virus to evade host immune defenses.
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88
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St George JA, Pennington SE, Kaplan JM, Peterson PA, Kleine LJ, Smith AE, Wadsworth SC. Biological response of nonhuman primates to long-term repeated lung exposure to Ad2/CFTR-2. Gene Ther 1996; 3:103-16. [PMID: 8867858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have assessed the safety and efficacy of repeated adenovirus vector administration by exposing the left caudal lung lobe of rhesus monkeys to as many as 17 exposures of Ad2/CFTR-2. After nine doses of either 3 x 10(9) or 3 x 10(10) infectious units, the monkeys were free of adverse effects as assessed by thoracic radiographs, CBCs, clinical chemistries, arterial blood gases, and physical and clinical signs. In some animals elevated protein levels and increased numbers of cells were recovered in bronchoalveolar lavage (BAL), and in all animals there were increased proportions of lymphocytes in the BAL. After 11 doses, two animals were killed. In the lower dose animal (3 x 10(9) IU), there was little histopathology evident. In the higher dose animal (3 x 10(10) IU), histopathology was largely confined to a focal fibrotic lesion that may have been associated with treatment. At the tenth exposure, the dose was increased to 6 x 10(10) or 3 x 10(11) IU. There was evidence of lung injury by thoracic radiographs after two additional exposures and an increase in protein and number of cells in the BAL. The animals were still free of evidence of adverse effects by other parameters, but histopathologic changes were noted upon death. After 15 or 17 doses, three animals were instilled with Ad2/beta gal-2 and killed 3 days later. These animals had greatly reduced levels of transgene expression when compared with controls.
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89
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Smith AE. The economics of medicine in Florida. THE JOURNAL OF THE FLORIDA MEDICAL ASSOCIATION 1996; 83:75-6. [PMID: 8850196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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90
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Zhai Y, Yang JC, Kawakami Y, Spiess P, Wadsworth SC, Cardoza LM, Couture LA, Smith AE, Rosenberg SA. Antigen-specific tumor vaccines. Development and characterization of recombinant adenoviruses encoding MART1 or gp100 for cancer therapy. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1996; 156:700-10. [PMID: 8543823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The human melanoma tumor Ags, MART1 and gp100, are specifically recognized by HLA-A2-restricted CD8+ CTLs derived from melanoma patients and appear to be involved in tumor regression. In order to develop immunizing vectors for the treatment of patients with metastatic melanoma, replication-defective recombinant adenoviruses, Ad2CMV-MART1 and Ad2CMV-gp100, which encode these tumor Ags, have been generated. Infection of non-Ag expressing HLA-A2+ cell lines A375 and MDA-231 with the vectors resulted in recognition by Ag-specific CTLs as demonstrated by specific target cell lysis and release of cytokines, including IFN-gamma, TNF-alpha, and granulocyte-macrophage-CSF. Sodium butyrate and TNF-alpha can further augment adenovirus-mediated transgene expression and increase recognition by specific CTLs. Although adenovirus-infected cells expressed the E3/19K protein at detectable levels, significant reduction of surface MHC class I expression was observed in only 3 of 10 tumor cell lines infected with either Ad2CMV-MART1 or Ad2CMV-gp100. Because of the suspected homology between the human MART1 and gp100 genes and their murine counterparts, we immunized C57BL/6 mice with these recombinant adenoviruses and demonstrated that immunization with Ad2CMV-gp100 could protect mice from murine melanoma B16 challenge administered intradermally. Depletion of CD8+ but not CD4+ T cells in vivo from Ad2CMV-gp100-vaccinated mice eliminated the protective effect. The anti-gp100 T cells induced by Ad2CMV-gp100 vaccinated appeared to be responsible for the protection. Thus, these recombinant adenoviruses encoding tumor Ags may be useful as vaccines to induce specific T cell immunity for cancer therapy.
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MESH Headings
- Adenoviridae/genetics
- Adenovirus E3 Proteins/physiology
- Animals
- Antigens, Neoplasm
- Butyrates/pharmacology
- Butyric Acid
- Cell Line
- DNA, Recombinant
- Defective Viruses/genetics
- Gene Expression Regulation, Viral/drug effects
- Genetic Vectors/genetics
- HLA-A2 Antigen/immunology
- Humans
- Immunodominant Epitopes/genetics
- Immunodominant Epitopes/immunology
- Immunotherapy, Active
- Lymphocytes, Tumor-Infiltrating/immunology
- MART-1 Antigen
- Melanoma/immunology
- Melanoma/therapy
- Melanoma, Experimental/immunology
- Melanoma, Experimental/prevention & control
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/immunology
- Mice
- Mice, Inbred C57BL
- Neoplasm Proteins/genetics
- Neoplasm Proteins/immunology
- Neoplasm Transplantation
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/immunology
- T-Lymphocytes, Cytotoxic/immunology
- Tumor Necrosis Factor-alpha/pharmacology
- Vaccination/methods
- Vaccines, Synthetic/therapeutic use
- gp100 Melanoma Antigen
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91
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Zhai Y, Yang JC, Kawakami Y, Spiess P, Wadsworth SC, Cardoza LM, Couture LA, Smith AE, Rosenberg SA. Antigen-specific tumor vaccines. Development and characterization of recombinant adenoviruses encoding MART1 or gp100 for cancer therapy. THE JOURNAL OF IMMUNOLOGY 1996. [DOI: 10.4049/jimmunol.156.2.700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Abstract
The human melanoma tumor Ags, MART1 and gp100, are specifically recognized by HLA-A2-restricted CD8+ CTLs derived from melanoma patients and appear to be involved in tumor regression. In order to develop immunizing vectors for the treatment of patients with metastatic melanoma, replication-defective recombinant adenoviruses, Ad2CMV-MART1 and Ad2CMV-gp100, which encode these tumor Ags, have been generated. Infection of non-Ag expressing HLA-A2+ cell lines A375 and MDA-231 with the vectors resulted in recognition by Ag-specific CTLs as demonstrated by specific target cell lysis and release of cytokines, including IFN-gamma, TNF-alpha, and granulocyte-macrophage-CSF. Sodium butyrate and TNF-alpha can further augment adenovirus-mediated transgene expression and increase recognition by specific CTLs. Although adenovirus-infected cells expressed the E3/19K protein at detectable levels, significant reduction of surface MHC class I expression was observed in only 3 of 10 tumor cell lines infected with either Ad2CMV-MART1 or Ad2CMV-gp100. Because of the suspected homology between the human MART1 and gp100 genes and their murine counterparts, we immunized C57BL/6 mice with these recombinant adenoviruses and demonstrated that immunization with Ad2CMV-gp100 could protect mice from murine melanoma B16 challenge administered intradermally. Depletion of CD8+ but not CD4+ T cells in vivo from Ad2CMV-gp100-vaccinated mice eliminated the protective effect. The anti-gp100 T cells induced by Ad2CMV-gp100 vaccinated appeared to be responsible for the protection. Thus, these recombinant adenoviruses encoding tumor Ags may be useful as vaccines to induce specific T cell immunity for cancer therapy.
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92
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Smith AE. Advocacy. THE JOURNAL OF THE FLORIDA MEDICAL ASSOCIATION 1996; 83:7-8. [PMID: 8849973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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93
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Schiavi SC, Abdelkader N, Reber S, Pennington S, Narayana R, McPherson JM, Smith AE, Hoppe H, Cheng SH. Biosynthetic and growth abnormalities are associated with high-level expression of CFTR in heterologous cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1996; 270:C341-51. [PMID: 8772462 DOI: 10.1152/ajpcell.1996.270.1.c341] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
An inducible gene amplification system was utilized to study the effects of overexpression of cystic fibrosis transmembrane conductance regulator (CFTR) in vitro. BTS, a monkey kidney cell line expressing a temperature-sensitive simian virus 40 (SV-40) large T antigen was stably transfected at the nonpermissive temperature with a plasmid containing an SV-40 origin of replication and the cDNA for either the wild-type CFTR or the mutant G551D-CFTR. Shift of the isolated cell lines to the permissive temperature resulted in induction and accumulation to high levels of the CFTR plasmid, mRNA, and protein. However, high-level expression of CFTR was transient in both BTS-CFTR and BTS-G551D cells due to a decrease in their respective levels of CFTR mRNA. Because G551D-CFTR only exhibits residual Cl channel activity, this suggests that the observed downregulation with BTS-G551D cells may have been induced by either the physical presence of high amounts of CFTR or some low threshold level of Cl- channel activity. Examination of cell growth properties revealed a correlation between high-level expression of wild-type CFTR and growth arrest of the cells at the G2/M phase. However, similar induction of the G551D-CFTR mutant showed only a slight growth inhibition and little enrichment of cells at the G2/M phase. Cytofluorographic analysis further revealed that BTS-CFTR cells were significantly larger than parental BTS or BTS-G551D cells at all stages of the cell cycle. These results indicate that CFTR overexpression is capable of inducing its own downregulation and that high levels of Cl- channel activity can result in increased cell volume and subsequent cell growth abnormalities.
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94
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95
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Lee AS, Hong MK, Smith AE. Analysis of 2,2,2-trifluoroethyl derivatives of carboxylic acid herbicides by gas chromatography with mass-selective and electron capture detection. J AOAC Int 1995; 78:1459-64. [PMID: 8664583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A method for derivatizing carboxylic acid herbicides with 2,2,2-trifluoroethanol (TFE) in preparation for gas chromatographic (GC) analysis was developed. Esterification efficiency was determined by GC with electron capture detection (ECD), and esters were identified by GC with mass-selective detection (MSD). On the basis of reaction temperature for optimum esterification efficiency, 13 common carboxylic acid herbicides were separated into 2 groups before reaction with TFE. TFE derivatization was optimized for simultaneous analyses by altering reaction temperature, re action time, and concentration of sulfuric acid in reaction solutions. The method is simple, safe, and economical, and it gives good resolution without a laborious cleanup. Recovery of 13 analytes from water, taken from a pesticide residue well, was greater than 80% for all except 2 analytes. The well-water was fortified with analytes at the lower microgram-per-liter concentrations required for detection of pesticide residues in potable water systems. The method can simultaneously determine multiple herbicide residues in water samples with a high degree of accuracy and precision.
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96
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Thompson RS, McAfee TA, Stuart ME, Smith AE, Wilson J, Handley MR. A review of clinical prevention services at group health cooperative of Puget Sound. Am J Prev Med 1995; 11:409-16. [PMID: 8775667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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97
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Abstract
The use of DNA as a drug is both appealing and simple in concept. Indeed in many instances the feasibility of such an approach has been established using model systems. In practical terms, however, the delivery of DNA to human tissues presents a wide variety of problems that differ with each potential therapeutic application. In this review, the design, production, and application of viral vectors for human gene therapy are considered. Although viral vectors are an obvious starting point because viruses have evolved efficient mechanisms to introduce and express their nucleic acid into recipient cells, by the same token the viral hosts have evolved sophisticated mechanisms to rid themselves of such pathogens. The challenge for the therapeutic use of viral vectors is to achieve efficient and often extended expression of the exogenous gene while evading the host defenses. Methodology used and progress towards that goal are reviewed.
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98
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Armentano D, Sookdeo CC, Hehir KM, Gregory RJ, St George JA, Prince GA, Wadsworth SC, Smith AE. Characterization of an adenovirus gene transfer vector containing an E4 deletion. Hum Gene Ther 1995; 6:1343-53. [PMID: 8590739 DOI: 10.1089/hum.1995.6.10-1343] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We describe the construction and characterization of an adenovirus type 2 vector, Ad2E4ORF6, which has been modified in the E4 region to contain only open reading frame 6. When assayed in cultured cells, Ad2E4ORF6 virus replication is slightly delayed but viral DNA synthesis, host-cell protein synthesis shut-off, and virus yield are indistinguishable from wild type. Late protein synthesis is normal with the exception of fiber synthesis, which is reduced approximately 10-fold. Despite the reduced fiber synthesis, Ad2E4ORF6 viral particles appear to contain a full complement of fiber protein. Virus replication in cotton rats indicates that Ad2E4ORF6 is replication defective in vivo. This may have safety implications for the development adenovirus vectors in that virus arising by recombination in the E1 region of an Ad2E4ORF6-based vector would be defective for growth in vivo. The deletion of E4 open reading frames that are not required for virus growth in vitro increases the cloning capacity of adenovirus vectors by 1.9 kb and may be generally useful for the construction of adenovirus vectors containing large cDNA inserts and/or regulatory elements. We describe the inclusion of the A2E4ORF6 modification in a recombinant adenovirus vector, Ad2/CFTR-2, for gene transfer of the human cystic fibrosis transmembrane regulator (CFTR).
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Scheule RK, Bagley RG, Erickson AL, Wang KX, Fang SL, Vaccaro C, O'Riordan CR, Cheng SH, Smith AE. Delivery of purified, functional CFTR to epithelial cells in vitro using influenza hemagglutinin. Am J Respir Cell Mol Biol 1995; 13:330-43. [PMID: 7544596 DOI: 10.1165/ajrcmb.13.3.7544596] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
To assess the feasibility of protein replacement as a potential therapy for cystic fibrosis, we have evaluated the ability of influenza hemagglutinin (HA) to mediate the delivery of purified cystic fibrosis transmembrane conductance regulator (CFTR) to recipient cells in vitro. CFTR was purified from both CHO cells and Sf9 cells and reconstituted into two different types of vesicular delivery vehicles. In one, CFTR and HA were co-reconstituted into the same lipid vesicle. After binding to the cell surface, delivery of CFTR to the recipient cell was achieved by a transient, low-pH activation of the fusion activity of HA. A second delivery strategy used HA virosomes together with purified CFTR that had been reconstituted into vesicles containing gangliosides, a receptor for HA. After binding of the HA virosomes and CFTR-containing vesicles to the recipient cells, delivery to the plasma membrane again was achieved by a transient pH drop. Delivery of functional CFTR was assessed using the SPQ fluorescence assay. Functional CFTR was detected in a fraction (> 20%) of the recipient cells using this assay. Quantitative binding and fusion assays using radiolabeled virosomes and lipid vesicles showed that on the order of 1,000 of the added CFTR-containing vesicles bound to each C127 cell under the conditions of our delivery protocols. However, only a fraction of these vesicles fused and delivered CFTR to the cell plasma membrane. The two delivery strategies were found to be approximately equivalent in their ability to deliver active CFTR, and there were no significant differences between deliveries using purified CFTR from either cell source. These feasibility studies suggest that purified CFTR can be delivered to a recipient cell in a functional form and therefore represent a significant step in establishing the concept of protein replacement as a therapy for cystic fibrosis.
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Manavalan P, Dearborn DG, McPherson JM, Smith AE. Sequence homologies between nucleotide binding regions of CFTR and G-proteins suggest structural and functional similarities. FEBS Lett 1995; 366:87-91. [PMID: 7540563 DOI: 10.1016/0014-5793(95)00463-j] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Sequence homology between the alpha-subunits of G-proteins and other GTP-binding proteins and certain regions within the nucleotide binding domains (NBDs) of cystic fibrosis transmembrane conductance regulator (CFTR) indicates that these protein structures may be similar. A sequence alignment of the NBDs of CFTR and NBDs from other membrane transporters, forms the basis of a structural model. This model predicts that one of the conserved sequences GGQR, within which a number of CF mutations occur, forms part of the nucleotide binding pocket and serves as an ON/OFF conformational switch as observed in GTP binding proteins. Furthermore, based on subtle sequence differences between the first and second NBDs of CFTR and from structure-activity data, we suggest that the nucleotide binding site environments of the two NBDs are different.
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