Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.5.4.4 (adenosine deaminase)
5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During the past 6 y, 29 adenosine deaminase (ADA)-deficient patients with combined immunodeficiency have been treated with polyethylene glycol (PEG)-modified bovine ADA (PEG-ADA). We have monitored plasma ADA activity, metabolic effects of treatment, and the evolution of antibody to PEG-ADA in these patients, in collaboration with immunologists and clinicians in North America, Europe, and Australia, who have monitored immune function and clinical response to treatment. This article summarizes the current status of PEG-ADA therapy and provides recommendations for its use. Recovery of specific immune function during treatment with PEG-ADA is illustrated for three patients, who represent early, delayed, these patients have entered a trial of gene therapy, but continue to receive enzyme replacement.
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PMID:Enzyme replacement therapy with polyethylene glycol-adenosine deaminase in adenosine deaminase deficiency: overview and case reports of three patients, including two now receiving gene therapy. 843 74

Deficiency of adenosine deaminase (ADA) results in severe combined immunodeficiency. Clinical cure has been observed in several ADA-severe combined immunodeficiency patients after bone marrow transplantation in which only donor T cells were engrafted, suggesting that T-cell correction alone is sufficient for full immune reconstitution. Children without an HLA-matched donor have been treated with polyethylene glycol-ADA as enzyme replacement therapy, resulting in varying degrees of immunologic and clinical improvement. In September 1990, we began treating a 4-y-old girl with periodic infusions of autologous culture-expanded T cells genetically corrected by insertion of a normal ADA gene using retroviral-mediated gene transfer with the LASN vector. After 2 y of polyethylene glycol-ADA treatment and before gene therapy, she continued to experience recurrent infections, was anergic and lymphopenic, and was deficient in isohemagglutinins. After seven infusions totaling 7 x 10(10) T cells, she has demonstrated a substantial increase in the number of circulating T cells (571/microL pre-gene therapy versus a mean of 1995/microL with gene therapy infusions every 6-8 wk) and the ADA activity in her peripheral blood T cells has increased > 10-fold. The increase in T-cell numbers and ADA activity has been associated with the development of positive delayed-type hypersensitivity skin tests, a significant increase in the level of isohemagglutinins, the regrowth of tonsils, and a decreased number of infectious illnesses. This improvement has persisted during suspension of treatment for more than 6 mo. A second patient treated since February 1991 has shown similar improvement in immune status.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Development of gene therapy for immunodeficiency: adenosine deaminase deficiency. 843 75

An adenosine deaminase (ADA) deficient patient with severe combined immunodeficiency (SCID) developed resistance to therapeutic injections of bovine ADA conjugated to polyethylene glycol (PEG-ADA). This 18-year-old girl was diagnosed as having partial ADA deficiency at age 7 years, and was started on bovine conjugated PEG-ADA at age 15 years. The weekly dose of 15 U/kg led to clinical improvement with resolution of sinusitis and bronchitis within 2 months and normalization of some T cell functions. After 5 months, however, she developed an inhibitory antibody to ADA, became refractory to treatment with PEG-ADA, and clinically and immunologically deteriorated. This antibody was successfully suppressed over a 4-month period with a combination of prednisone (2 mg/kg/day), intravenous immunoglobulin (2 g/kg/dose), and discontinuing the PEG-ADA injections for 7 weeks. The PEG-ADA injections were then restarted at a higher dose (20 U/kg/dose, twice a week). With the suppression of the inhibitory antibody, her clinical and immunologic status improved to previously achieved level. She has subsequently continued treatment for over 36 months, receiving a single weekly dose of PEG-ADA (20 U/kg/week) with sustained clinical and immunologic improvement, including weakly positive antigen-specific T cell proliferative responses to tetanus and Candida.
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PMID:Suppression of an antibody to adenosine-deaminase (ADA) in an ADA-deficient patient receiving polyethylene glycol modified adenosine deaminase. 850 39

Severe combined immunodeficiency (SCID) due to adenosine deaminase (ADA) deficiency is a fatal recessive disorder caused by mutations in the gene encoding ADA. Based on the first clinical trial of two young girls with ADA-deficient SCID by recombinant retrovirus-mediated gene transfer at the National Institute of Health of USA, we prepared to treat a four-year-old boy with ADA-deficient SCID who had been treated with PEG-ADA for 3 years. Approval to perform the clinical trial of gene therapy by using his peripheral blood T lymphocytes as the target and recombinant retroviral vector (LASN) as the vector for ADA gene transfer was obtained from both of the Ministry of Health and Welfare and the Ministry of Education, Science, Sports and Culture on 13 February, 1995. The first clinical trial of gene therapy for the patient was initiated on 1 August 1995. He received 8 x 10(8) LASN-transduced lymphocytes in an injection administered intravenously on 8 August and 2.5 x 10(9) transduced lymphocytes on 4 September without any side reactions. The procedure, safety and efficacy of clinical trial of gene therapy were discussed.
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PMID:[Gene therapy for adenosine deaminase deficiency]. 872 72

The molecular mechanisms of the primary immunodeficiencies have been further explored and provide insights into the regulation of the immune response and its role in autoimmune disease, infection, and malignancy. The critical role of CD40-CD40 ligand-mediated effects in T cell-dependent B cell activation, shown through the study of patients with common variable immunodeficiency and hyper IgM syndrome, suggests a potential narrow target for immunomodulatory therapy. A mouse model for chronic granulomatous disease has been developed and promises to be a source of future information. Optimal cost-effective therapy for primary immunodeficiencies continues to be defined, with the results of a large series of patients treated with subcutaneous immunoglobulin infusions reported. Further experience with polyethylene glycol adenosine deaminase and interleukin-2 conjugates is discussed.
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PMID:Immunodeficient states and associated rheumatic manifestations. 886 40

We present a girl with severe combined immunodeficiency (SCID) from adenosine deaminase (ADA) deficiency who developed insulin dependent diabetes mellitus (IDDM). This combination of features has not been previously reported. Because HLA typing (DQbeta-57 Asp/Asp and DQalpha-52 Ser/Ser) showed no alleles usually associated with IDDM, and ICA were repeatedly negative even after treatment with PEG-ADA and gene transplant, hypotheses on the pathogenesis of diabetes mellitus in this patient are discussed.
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PMID:A girl with diabetes and severe combined immunodeficiency from adenosine deaminase deficiency. 936 70

Adenosine deaminase-deficient severe combined immunodeficiency was the first disease investigated for gene therapy because of a postulated production or survival advantage for gene-corrected T lymphocytes, which may overcome inefficient gene transfer. Four years after three newborns with this disease were given infusions of transduced autologous umbilical cord blood CD34+ cells, the frequency of gene-containing T lymphocytes has risen to 1-10%, whereas the frequencies of other hematopoietic and lymphoid cells containing the gene remain at 0.01-0.1%. Cessation of polyethylene glycol-conjugated adenosine deaminase enzyme replacement in one subject led to a decline in immune function, despite the persistence of gene-containing T lymphocytes. Thus, despite the long-term engraftment of transduced stem cells and selective accumulation of gene-containing T lymphocytes, improved gene transfer and expression will be needed to attain a therapeutic effect.
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PMID:T lymphocytes with a normal ADA gene accumulate after transplantation of transduced autologous umbilical cord blood CD34+ cells in ADA-deficient SCID neonates. 1198 64

We previously reported successful peripheral T cell-directed gene therapy in a boy with adenosine deaminase (ADA)-SCID. In the present study, to better understand the reconstitutive effect of this gene therapy on his immunological system, we investigated the in vivo kinetics and functional subsets of T cells in PBL. Apparent immunological improvements were obtained after infusion of transduced cells at more than 4 x 108 cells/kg/therapy/3 mo. Frequency of ADAcDNA-integrated cells in PBL, ADA activity in PBL and clinical improvement showed good correlation, even though CD8+ cells gradually became predominant in PBL. On the basis that polyethylene glycol (PEG)-ADA was maintained at the same dosage as before gene therapy, we consider that his immunological improvement resulted from the gene therapy itself. Most CD3+ cells in PBL after gene therapy expressed TCRalphabeta. Analysis of TCR repertoire based on TCR V region usage revealed no expansion of limited clones in his PBL. The T cell subset cells CD8+CDw60+ and CD8+CD27+CD45RA-, which are reported to provide substantial help to B cells, were maintained throughout the gene therapy. Furthermore, his reconstituted peripheral T cells helped normal B cells to produce substantial IgG in vitro. Expression of both Th1- and Th2-type cytokine genes was induced in his reconstituted T cells at the same comparably high level as in normal subjects. Collectively, these results provide evidence of persistent and distinct functions of transduced cells in this patient's PBL after gene therapy.
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PMID:In vivo kinetics of transduced cells in peripheral T cell-directed gene therapy: role of CD8+ cells in improved immunological function in an adenosine deaminase (ADA)-SCID patient. 1043 69

Polymer conjugation is of increasing interest in pharmaceutical chemistry for delivering drugs of simple structure or complex compounds such peptides, enzymes and oligonucleotides. For long time drugs, mainly with antitumoral activity, have been coupled to natural or synthetic polymers with the purpose of increasing their blood permanence time, taking advantage of the increased mass that reduces kidney ultrafiltration. However only recently complex constructs were devised that exploit the 'enhanced permeability and retention' (EPR) effect for an efficient tumor targeting, the high molecular weight for adsorption or receptor mediated endocytosis and finally a lysosomotropic targeting, taking advantage of acid labile bonds or cathepsin susceptible polypeptide spacers between polymer and drug. New original, very active conjugates of this type, as those based on poly(hydroxyacrylate) polymers, are already in advanced state of development. Labile oligonucleotides, including antisense drugs, were also successfully coupled to polymers in view of an increased cell penetration and stabilization towards nucleases. However, the most active research activity resides in the field of polypeptides and proteins delivery, mainly for the two following reasons: first of all because a great number of therapeutically interesting compounds are now being produced by genetic engineering in large quantity and, secondly, because these products are difficult to administer to patients for several inherent drawbacks. Proteins are in fact easily digested by many endo- and exo-peptidases present in blood or in other body districts; most of them are immunogenic to some extent and, finally, they are rapidly excreted by kidney ultrafiltration. Covalent polymer conjugation at protein surface was demonstrated to reduce or eliminate these problems, since the bound polymer behaves like a shield hindering the approach of proteolytic enzymes, antibodies, or antigen processing cell. Furthermore, the increase of the molecular weight of the conjugate allows to overcome the kidney elimination threshold. Many successful results were already obtained in peptides and proteins, conjugated mainly to water soluble or amphiphilic polymers like poly(ethylene glycol) (PEG), dextrans, or styrenemaleic acid anhydride. Among the most successful are the conjugates of asparaginase, interleukin-2 or -6 and neocarcinostatin, to remind some antitumor agents, adenosine deaminase employed in a genetic desease treatment, superoxide dismutase as scavenger of toxic radicals, hemoglobin as oxygen carrier and urokinase and streptokinase as proteins with antithrombotic activity. In pharmaceutical chemistry the conjugation with polymers is also of great importance for synthetic applications since many enzymes without loss of catalytic activity become soluble in organic solvents where many drug precursors are. The various and often difficult chemical problems encountered in conjugation of so many different products prompted the development of many synthetic procedures, all characterized by high specificity and mild condition of reaction, now known as 'bioconjugation chemistry'. Bioconjugation developed also the design of new tailor-made polymers with the wanted molecular weight, shape, structure and with the functional groups needed for coupling at the wanted positions in the chain.
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PMID:Bioconjugation in pharmaceutical chemistry. 1051 Aug 47

Polyethylene glycol-conjugated adenosine deaminase (pegademase) is used for enzyme replacement therapy for patients with severe combined immunodeficiency caused by adenosine deaminase deficiency. The entrapment of pegademase within human energy-replete carrier erythrocytes using a hypo-osmotic dialysis procedure was investigated with the objective of prolonging the in vivo circulatory half-life of the enzyme and maintaining therapeutic blood levels. Native unmodified adenosine deaminase (ADA) was similarly studied. The efficiency of pegademase entrapment was low (9%) whereas the entrapment of native unmodified ADA was substantial (50%), suggesting that the polyethylene glycol side-chains were impeding intracellular entrapment. The biochemical characteristics and the osmotic fragility of these carrier erythrocytes were not adversely affected by the entrapment of either pegademase or native ADA. In vivo survival studies of pegademase-loaded 51Cr-labelled carrier erythrocytes in an ADA-deficient adult patient showed a mean cell half-life of 16 d. Carrier erythrocyte-entrapped pegademase and native ADA had in vivo half-lives of 20 and 12.5 d, respectively, demonstrating that entrapment prolongs the half-life over that of plasma pegademase, which has a circulating half-life of 3-6 d. These results provide the basis for a more extensive clinical evaluation of carrier erythrocyte-entrapped native adenosine deaminase therapy.
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PMID:In vitro and in vivo studies with human carrier erythrocytes loaded with polyethylene glycol-conjugated and native adenosine deaminase. 1088 3


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