       Document 0537
 DOCN  M9620537
 TI    Stimulation of thymocytes before and after positive selection results in
       the induction of different NF-kappa B/Rel protein complexes.
 DT    9602
 AU    Moore NC; Girdlestone J; Anderson G; Owen JJ; Jenkinson EJ; Centre for
       Clinical Research in Immunology & Signalling, Medical; School,
       University of Birmingham, United Kingdom.
 SO    J Immunol. 1995 Nov 15;155(10):4653-60. Unique Identifier : AIDSLINE
       MED/96062280
 AB    Positive selection triggers the differentiation of immature CD4+8+TCRlow
       thymocytes into TCRhigh single-positive CD4+ or CD8+ cells and is
       associated with major changes in gene expression. However, little is
       known about the DNA binding factors controlling these fundamental
       changes. Here we have examined NF-kappa B/Rel subunit expression and
       DNA-binding activity in developing thymocytes before and after the
       induction of positive selection. We show that positive selection is
       accompanied by the strong up-regulation of c-rel mRNA expression and the
       constitutive activation of p50/p65 and p50/c-Rel NF-kappa B/Rel
       complexes, confirming the activation-like status of cells undergoing
       positive selection. Moreover, CD69+ cells that have initiated positive
       selection (but not their preselection CD4+8+TCR- precursors) respond to
       stimulation by the preferential activation of c-Rel-containing
       DNA-binding complexes. Because the different NF-kappa B/Rel dimers have
       distinct transcriptional activities and binding site preferences, this
       preferential activation of c-Rel-containing DNA-binding complexes may
       well have implications for the changes in gene expression and functional
       response associated with positive selection.
 DE    Amino Acid Sequence  Animal  Base Sequence  Cell Differentiation
       CD4-Positive T-Lymphocytes/*IMMUNOLOGY  CD8-Positive
       T-Lymphocytes/*IMMUNOLOGY  Gene Expression Regulation  *Lymphocyte
       Transformation  Mice  Mice, Inbred BALB C  Molecular Sequence Data
       NF-kappa B/*BIOSYNTHESIS  Receptors, Antigen, T-Cell/*IMMUNOLOGY
       Support, Non-U.S. Gov't  T-Lymphocyte Subsets  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

