Document 0199
 DOCN  M9650199
 TI    Lack of inducible nitric oxide synthase activity in T cell clones and T
       lymphocytes from naive and Leishmania major-infected mice.
 DT    9605
 AU    Thuring H; Stenger S; Gmehling D; Rollinghoff M; Bogdan C; Institute for
       Clinical Microbiology and Immunology, University of; Erlangen-Nurnberg,
       Germany.
 SO    Eur J Immunol. 1995 Dec;25(12):3229-34. Unique Identifier : AIDSLINE
       MED/96140654
 AB    Nitric oxide (NO) generated by the inducible isoform of nitric oxide
       synthase (iNOS) is implicated in a number of immunological processes
       including killing of intracellular parasites, suppression of T cell
       proliferation, production of cytokines and destruction of tissue in
       autoimmune diseases. Considering that cytokine-activated mouse
       macrophages, fibroblasts and endothelial cells are potent producers of
       NO, we investigated whether T cells, as central participants in immune
       responses, can also be activated for the release of NO. Neither
       thymocytes nor type 1 or type 2 T helper cell clones generated
       significant amounts of nitrite (the stable end product of NO in culture
       supernatants) when stimulated by T cell mitogens, cytokines or antigen
       in the presence of irradiated antigen-presenting cells. Similarly, T
       cells freshly isolated from mice acutely infected with the intracellular
       pathogen Leishmania major did not produce NO upon restimulation in
       vitro. The lack of NO production was not due to the expression of
       enzymatically inactive iNOS, as we were unable to detect any iNOS
       protein in activated T helper clones or in freshly isolated T cells from
       infected mice by Western (protein) blot analysis. Finally, we tested
       whether iNOS expression in T cells might be restricted to a minor
       subpopulation and therefore only detectable on a single cell level.
       After immunofluorescence staining of lymph node or spleen cells from
       infected mice with antibodies against iNOS, F4/80- or Thy-1-antigen,
       macrophages, but no T cells, were found to express iNOS. Thus, we have
       no evidence that activated T helper cell clones or T cells from L.
       major-infected mice are high producers of NO.
 DE    Animal  Clone Cells/ENZYMOLOGY  Enzyme Induction/IMMUNOLOGY  Fluorescent
       Antibody Technique, Indirect  Leishmania major/*IMMUNOLOGY
       Leishmaniasis, Cutaneous/ENZYMOLOGY/*IMMUNOLOGY  Mice  Mice, Inbred
       C57BL  Nitric-Oxide Synthase/*BIOSYNTHESIS/*DEFICIENCY  Support,
       Non-U.S. Gov't  T-Lymphocytes/*ENZYMOLOGY/IMMUNOLOGY  Th1
       Cells/ENZYMOLOGY/IMMUNOLOGY  Th2 Cells/ENZYMOLOGY/IMMUNOLOGY  JOURNAL
       ARTICLE

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