title: Effects of immunomodulators on ecto-5'-nucleotidase activity on blood mononuclear cells in vitro.
abstract: In this study the effects of immunomodulators on the ecto-5'-nucleotidase (ecto-5'-NT) activity on blood mononuclear cells (BMC) were examined in vitro. Interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) decreased the level of ecto-5'-NT activity on BMC whereas prostaglandin E2 (PGE2) increased the ecto-5'-NT level. All three immunomodulators influenced the ecto-5'-NT activity of isolated monocytes whereas only IL-4 and PGE2 had an effect on the enzyme level on isolated lymphocytes. The effect was dependent upon protein synthesis. The effect was dose dependent: IL-4 was effective at concentrations down to 0.5 U/ml, IFN-gamma down to 40 U/ml and PGE2 at nanomolar concentrations. These data indicate that immunomodulators may also take part in the regulation of ecto-5'-NT activity on BMC in vivo. BMC from 7 patients with different immunodeficiency syndromes showed decreased ecto-5'-NT activity on freshly isolated cells. However, following culture ecto-5'-NT activity was increased above the level found on freshly isolated BMC from healthy persons. On BMC from 3 patients with hypogammaglobulinaemia, the effect of IL-4 on the level of ecto-5'-NT activity was identical to that found on BMC from healthy donors, whereas PGE2 increased ecto-5'-NT activity on BMC from only 1 of the 3 patients investigated. The decreased ecto-5'-NT activity of BMC from patients with immunodeficiency may thus be due to a defective regulation of ecto-5'-NT activity in vivo.
authors.affiliation: Department of Infectious Diseases M, University Hospital, Copenhagen, Denmark.
authors.forename: L D
authors.initials: LD
authors.lastname: Christensen
authors.forename: V
authors.initials: V
authors.lastname: Andersen
authors.forename: P
authors.initials: P
authors.lastname: Nygaard
authors.forename: K
authors.initials: K
authors.lastname: Bendtzen
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism*; D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000361:Agammaglobulinemia / Q000201:enzymology; D015232:Dinoprostone / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000201:enzymology*
chemical_list: D000276:Adjuvants, Immunologic; D015847:Interleukin-4; D007371:Interferon-gamma; D015720:5'-Nucleotidase; D015232:Dinoprostone