Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Low activity of 5'-nucleotidase (5'-ribonucleotide phosphohydrolase, EC 3.1.3.5) in T lymphoblasts may explain the marked sensitivity of this cell to deoxynucleotide accumulation when compared to B lymphoblasts. The relevance of such observations with cultured cells to the normal immune system requires the demonstration of similar differences in the 5'-nucleotidase activity of normal human lymphocyte subpopulations. Sheep erythrocyte (E) rosette-forming cells from normal thymus, tonsil, and peripheral mononuclear cells have 5'-nucleotidase activities of 1.7, 11.3, and 21.2 nmol/hr per 10(6) cells. Non-E-rosette forming cells from the peripheral blood or tonsil have 5'-nucleotidase activity comparable to the higher levels found in the peripheral E-RFC. Increased levels of 5'-nucleotidase activity may be a marker for post-thymic T lymphocytes. T lymphoblasts have 5'-nucleotidase activity similar to values demonstrated for E-RFC in thymus, whereas cultured B lymphoblasts have 5'-nucleotidase activity 15 times greater than that of T lymphoblasts. On the basis of these observations, the 5'-nucleotidase deficiency in congenital agammaglobulinemia has been reevaluated. In these patients the data indicate that peripheral E-rosette forming cells have the enzyme deficiency, demonstrating an abnormality of T lymphocytes in this disorder of immunoglobulin production.
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PMID:Distribution of 5'-nucleotidase in human lymphoid tissues. 31 65

Immunologic surface markers, 5'-nucleotidase activity, and in vitro cell functions were determined on peripheral blood mononuclear cells from 20 patients with primary humoral immunodeficiencies. Imbalances of T-cell subsets were a frequent finding and often associated with a deficiency of helper T lymphocytes, predominantly in common variable immunodeficiency. The magnitude of the blastogenic response to mitogens was subnormal in the majority of the samples and showed no correlations to the proportions of helper, suppressor T cells or monocytes in the cultures. Moderate to marked suppression of the pokeweed mitogen-driven allogenic B-cell maturation was mostly mediated by T lymphocytes but modified by monocytes in some patients. In identical twins, T lymphocytes selectively suppressed IgA production. Both in sex-linked agammaglobulinemia and common variable immunodeficiency the activity of 5'-nucleotidase was significantly lower than in controls. This deficiency was mediated by T lymphocytes and showed no correlations to imbalances of T-cell subpopulations or to alterations of lymphocyte functions.
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PMID:Surface markers, 5'-nucleotidase activity, and in vitro functions of lymphocytes from patients with primary humoral immunodeficiency. 298 85

With the use of a histochemical technique, 5'-nucleotidase activity was examined in peripheral blood lymphocytes from patients with primary hypogammaglobulinemia. Our current study demonstrates that the decrease in 5'-nucleotidase activity in congenital agammaglobulinemia, previously demonstrated by a radiochemical assay, is associated with a reduction in the number of cells containing 5'-nucleotidase rather than with a decrease of the enzyme activity per cell. Both sheep erythrocyte rosette-forming and nonrosette-forming PBMs have reduced percentages of 5'-nucleotidase-containing cells in subjects with the enzyme deficiency. The reduced percentage of 5'-nucleotidase-containing mononuclear cells in patients with congenital agammaglobulinemia was evident in both monocyte-contaminated and monocyte-depleted cell preparations.
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PMID:Histochemical evaluation of lymphocytes in hypogammaglobulinemia. Decreased number of 5'-nucleotidase-positive cells. 624 85