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Text File  |  1996-02-26  |  2KB  |  37 lines
  1.        Document 0520
  2.  DOCN  M9620520
  3.  TI    Positive selection of thymocytes involves sustained interactions with
  4.        the thymic microenvironment.
  5.  DT    9602
  6.  AU    Wilkinson RW; Anderson G; Owen JJ; Jenkinson EJ; Department of
  7.        Anatomy/Center for Clinical Research in Immunology; and Signaling,
  8.        Medical School, University of Birmingham, United; Kingdom.
  9.  SO    J Immunol. 1995 Dec 1;155(11):5234-40. Unique Identifier : AIDSLINE
  10.        MED/96072798
  11.  AB    CD4+8+ cortical thymocytes are critically dependent upon interaction
  12.        with the thymic epithelium to undergo positive selection and maturation
  13.        into single-positive CD4+ or CD8+ cells. Here we investigate further the
  14.        nature of this interaction and provide evidence that positive selection
  15.        requires sustained, rather than single hit, interaction with thymic
  16.        stromal cells. We also show that calcineurin-mediated signaling in
  17.        thymocytes is required for the initial stages of positive selection, but
  18.        is not essential throughout the period of thymocyte dependence on
  19.        stromal cell contact during positive selection. In addition, we show
  20.        that double-positive thymocytes that have initiated positive selection
  21.        (CD69+4+8+) and newly generated single-positive (CD69+4+) cells differ
  22.        markedly in response to the same stimulus through the TCR. The former
  23.        undergo deletion, whereas the latter proliferate, indicating that a
  24.        critical change in response to TCR ligation occurs within the narrow
  25.        developmental window between these two stages.
  26.  DE    Animal  Antigens, CD/IMMUNOLOGY  Antigens, Differentiation,
  27.        T-Lymphocyte/IMMUNOLOGY  Cell Differentiation/PHYSIOLOGY  Clonal
  28.        Deletion  CD4-Positive T-Lymphocytes/*CYTOLOGY/IMMUNOLOGY  CD8-Positive
  29.        T-Lymphocytes/*CYTOLOGY/IMMUNOLOGY  Epithelium/PHYSIOLOGY  Mice  Mice,
  30.        Inbred BALB C  Stromal Cells/PHYSIOLOGY  Superantigens/IMMUNOLOGY
  31.        Support, Non-U.S. Gov't  Thymus Gland/*CYTOLOGY/EMBRYOLOGY/GROWTH &
  32.        DEVELOPMENT/IMMUNOLOGY  JOURNAL ARTICLE
  33.  
  34.        SOURCE: National Library of Medicine.  NOTICE: This material may be
  35.        protected by Copyright Law (Title 17, U.S.Code).
  36.  
  37.