Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The application of bone marrow gene therapy has been stalled by the inability to achieve stable high-level gene transfer and expression in the totipotent stem cells. We show that retroviral vectors can stably introduce genes into antigen-specific murine and human T lymphocytes in culture. Murine helper T cells were transduced with the retroviral vector SAX to express both neomycin-resistance and human adenosine deaminase genes. These cells were expanded in culture and selected for expression of neomycin resistance with G418. The gene insertion, selection, and culture expansion did not alter antigen specificity or growth characteristics of the T cells in vitro. To determine if cultured T cells might be used for gene therapy, their persistence and continued expression of the introduced genes was evaluated in nude mice transplanted with the SAX-transduced T cells. G418-resistant cells could be readily recovered from the spleens of recipients of transduced T cells for several months. In addition, recovered cells continued to produce human adenosine deaminase. Based on these observations, we studied cultured human tumor-infiltrating lymphocytes as a candidate cell for a trial of gene transfer in man. Exponential cultures of interleukin-2-stimulated tumor-infiltrating lymphocytes were efficiently transduced with the neomycin-resistance gene using the retroviral vector N2. Gene insertion and subsequent G418 selection did not substantially alter the growth characteristics, interleukin 2 dependence, membrane phenotype, or cytotoxicity profile of the transduced T cells. These studies provided a portion of the experimental evidence supporting the feasibility of the presently ongoing clinical trials of lymphocyte gene therapy in cancer as well as in patients with adenosine deaminase deficiency.
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PMID:Lymphocytes as cellular vehicles for gene therapy in mouse and man. 201 35

Utilizing an enzyme-linked immunosorbent assay, we detected markedly elevated serum levels of soluble interleukin-2 (IL-2) receptors in patients with untreated pulmonary tuberculosis. In these patients, we also found that serum levels of soluble IL-2 receptors were closely correlated with serum adenosine deaminase levels (r = 0.869, p less than 0.001). Therefore, serum soluble IL-2 receptors appear to reflect the existence of active cell-mediated immunity in pulmonary tuberculosis and may prove to be a useful immunological marker for pulmonary tuberculosis.
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PMID:[Soluble interleukin-2 receptor levels in patients with pulmonary tuberculosis]. 278 40

Long-term bovine lymphocyte cultures were initiated by stimulation with alloantigens and maintained in continuous culture using medium containing recombinant human interleukin-2 (rh IL-2). The development of specific and lectin-dependent killing was monitored following primary alloantigen challenge. Cytolytic activity was barely detectable after 7 days of culture, but gradually increased with peak activity occurring after 21 days of culture. A panel of monoclonal antibodies (MoAb) was used to determine whether a shift in the antigen phenotype of the cell population occurred during culture. The primary cell type that grew in culture was of the T-cell lineage with minimal or no expression of class II antigens. The activities of adenosine deaminase (ADA), purine nucleotide phosphorylase (PNP), adenosine kinase (AK), deoxyadenosine kinase (dAK), deoxycytidine kinase (dCK), 5'-nucleotidase (5'-N), AMP deaminase, hypoxanthine-guanine phosphoribosyl transferase (HGPRT or HPRT), and adenine phosphoribosyl transferase (APRT) were measured by microassay in resting peripheral blood lymphocytes (PBL) and in cells from long-term cultures. Large increases in the activities of PNP and HPRT with a decrease in the activity of ADA were observed. The data show that long-term cultures of lymphocytes can be readily generated, and that sequential changes in antigenic phenotype and function can be monitored and correlated with quantitative changes in enzyme activity.
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PMID:Development and maintenance of bovine cytotoxic lymphocytes with recombinant human interleukin-2. 348 20

We performed limiting dilution culture of T cells from a patient affected by primary immunodeficiency as a result of complete lack of adenosine deaminase (ADA) activity and also affected by insulin-dependent diabetes mellitus (type I diabetes). Despite the occurrence of immunodeficiency, we were able to raise and grow T cell clones derived from this patient in long-term culture. These T cells displayed ADA enzymatic activity and produced interleukin-2 after engagement of their T cell receptor (TCR)/CD3 complex. We analyzed the TCR repertoire of such clones by nucleotide sequencing of TCR beta chains. The results show that the T cell clones express different V beta but similar J regions. However, the CDR3 regions which are implicated in antigen recognition were found to be heterogeneous.
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PMID:Long-term culture and T cell receptor analysis of T cell clones isolated from a patient with adenosine deaminase deficiency and type I diabetes. 795 66

We evaluated soluble interleukin-2 receptors (sIL-2R), neopterin and adenosine deaminase (ADA) in pleural effusions from 93 patients with tuberculosis, malignancies, uremia, pneumonia and other kinds of pleurisy. There were significantly elevated ADA (102.7 +/- 47 U/l) and sIL-2R (8,238 +/- 4,117 U/ml) values in tuberculous (TB) pleural fluids as compared with other non-TB pleural fluids (p < 0.005). The neopterin levels in pleural fluid were significantly lower in the cancer group (17.3 +/- 7.8 nmol/l; p < 0.005) and most strikingly elevated (309.4 +/- 112.2 nmol/l; p < 0.0001) in patients with uremic pleural effusions. Using cut-off values of 60 U/l in ADA and 5,000 U/l in sIL-2R, 92.0 and 86.9% of pleural effusions were TB in origin. Eighty-four percent of patients with malignant pleural effusions had neopterin levels less than 25 nmol/l.
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PMID:Neopterin, soluble interleukin-2 receptor and adenosine deaminase levels in pleural effusions. 804 18

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 measured the activity of adenosine deaminase (ADA) and the concentration of interleukin-1 beta (IL-1 beta), interleukin-2 (IL-2), interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in the pleural effusions from 28 patients with tuberculosis, 30 with neoplastic diseases, 25 with bacterial infections and 18 with congestive heart failure or liver cirrhosis. The levels of ADA (83.0 +/- 32.1 IU/L) and IFN-gamma (795.0 +/- 666.4 pg/ml) in tuberculous effusions were significantly higher than those in other groups (p < 0.0001). IL-1 beta level in the effusions of bacterial infections (265.2 +/- 379.2 pg/ml) was higher than that in other groups (p < 0.0001). TNF-alpha level in the effusions of tuberculosis (31.7 +/- 36.7 pg/ml) and bacterial infections (69.5 +/- 232.9 pg/ml) was higher than that in other groups. IL-8 level of exudative effusions was higher than that of transudates. IL-2 was only present in 4 effusions from tuberculosis and 1 effusion from bacterial infections. Diagnostic utilities of cytokines and ADA for tuberculous effusion were evaluated using receiver operating characteristics (ROC) curve analysis. The cut-off points of ADA, IL-1 beta, IL-8, TNF-alpha and IFN-gamma determined in this analysis were 54 IU/L, 5.5 pg/ml, 405 pg/ml, 4.5 pg/ml and 28 pg/ml, respectively and the sensitivity and the specificity of them were 88.0% and 95.9%, 19.1% and 74.1%, 57.1% and 63.2%, 81.0% and 77.2%, and 96.2% and 98.5%, respectively. In ADA, TNF-alpha and IFN-gamma, the areas under the curve (AUC) that represent the diagnostic accuracy were 0.968, 0.719 and 0.993, respectively. AUC of IFN-gamma was significantly higher than that of ADA or TNF-alpha. In tuberculous pleural effusion, IFN-gamma was significantly correlated with TNF-alpha, IL-1 beta and ADA. The correlation was also present between TNF-alpha and ADA.
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PMID:[Clinical significance of cytokine measurement in pleural effusion]. 938 55

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

CD26 is a T cell activation antigen that contains dipeptidyl peptidase IV activity and is known to bind adenosine deaminase. The mechanism by which CD26 costimulation potentiates T cell receptor-mediated T cell activation, leading to subsequent exertion of T cell effector function, is still not clearly defined. In this article, we demonstrate that CD26 localizes into lipid rafts, and targeting of CD26 to rafts is necessary for signaling events through CD26. Importantly, aggregation of CD26 by anti-CD26 mAb crosslinking also causes coaggregation of CD45 into rafts. Moreover, we show that CD26 directly binds to the cytoplasmic domain of CD45. Our results therefore indicate a mechanism whereby CD26 engagement promotes aggregation of lipid rafts and facilitates colocalization of CD45 to T cell receptor signaling molecules p56(Lck), ZAP-70, and TCRzeta, thereby enhancing protein tyrosine phosphorylation of various signaling molecules and subsequent interleukin-2 production.
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PMID:CD26-mediated signaling for T cell activation occurs in lipid rafts through its association with CD45RO. 1159 28

Adenosine, a purine nucleoside found at high levels in solid tumors, is able to suppress the recognition/adhesion and effector phases of killer lymphocyte-mediated tumor cell destruction. Here, we demonstrate that adenosine, at concentrations that are typically present in the extracellular fluid of solid tumors, exerts a profound inhibitory effect on the induction of mouse cytotoxic T cells, without substantially affecting T-cell viability. T-cell proliferation in response to mitogenic anti-CD3 antibody was impaired in the presence of 10 microM adenosine (plus coformycin to inhibit endogenous adenosine deaminase). Antigen-specific T-cell proliferation was similarly inhibited by adenosine. Anti-CD3-activated killer T (AK-T) cells induced in the presence of adenosine exhibited reduced major histocompatibility complex-unrestricted cytotoxicity against P815 mastocytoma cells in JAM and (51)Cr-release assays. Diminished tumoricidal activity correlated with reduced expression of mRNAs coding for granzyme B, perforin, Fas ligand and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), as well as with diminished Nalpha-CBZ-L-lysine thiobenzylester (BLT) esterase activity. Interleukin-2 and interferon-gamma synthesis by AK-T cells was also inhibited by adenosine. AK-T cells express mRNA coding for A(2A), A(2B) and A(3) receptors, but little or no mRNA coding for A(1) receptors. The inhibitory effect of adenosine on AK-T cell proliferation was blocked by an A(3) receptor antagonist (MRS1191) but not by an A(2) receptor antagonist (3,7-dimethyl-1-propargylxanthine [DMPX]). The A(3) receptor agonists (N(6)-2-(4-aminophenyl)ethyladenosine [APNEA] and N(6)-benzyl-5'-N-ethylcarboxamidoadenosine [N(6)-benzyl-NECA]) also inhibited AK-T cell proliferation. Adenosine, therefore, acts through an A(3) receptor to prevent AK-T cell induction. Tumor-associated adenosine may act through the same mechanism to impair the development of tumor-reactive T cells in cancer patients.
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PMID:Adenosine acts through an A3 receptor to prevent the induction of murine anti-CD3-activated killer T cells. 1199 7


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