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

The ubiquitous trace metal zinc has been discovered since a long time as an intrinsic element in all biological systems. However, its role other than structural or catalytic in enzymes is poorly defined. Zinc plays a determinative role both in primary and secondary T lymphocyte production. Experimental data support the notion that during intrathymic maturation, non-autoreactive, immunocompetent T cell clones are selected from the excess of immature thymocytes as a result of expansion of bone marrow derived prothymocytes in response to pleiotropically acting alarmon (s) and a subsequent escape via the thymic stroma cells from nucleotide-mediated "biochemical suicide". The activity of alarmon (Ap4A), nucleotide metabolizing enzymes (TdT, DNA polymerase, thymidine kinase, 5'-nucleotidase) and some of the soluble stromal cell products (FTS) require constitutive zinc. In the peripheral lymphoid organs the magnitude and duration of antigen induced, T cell mediated immunoreactions are regulated by T-cell growth factor (IL-2). Using receptor specific monoclonal antibody probes, it has been established recently that the intracellular role of IL-2 is probably to induce the phenotypic expression of high affinity transferrin receptors, known to be the main zinc transporter system in T-lymphocytes. The coordinative role of zinc in T lymphocyte development via the inducible metallothionein system is emphasized. Some clinical aspects of zinc metabolism are discussed.
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PMID:Zinc and immunity. 623 34