Pre-TCR signaling and CD8 gene bivalent chromatin resolution during thymocyte development

J Immunol. 2011 Jun 1;186(11):6368-77. doi: 10.4049/jimmunol.1003567. Epub 2011 Apr 22.

Abstract

The CD8 gene is silent in CD4(-)CD8(-) double-negative thymocytes, expressed in CD4(+)CD8(+) double-positive cells, and silenced in cells committing to the CD4(+) single-positive (SP) lineage, remaining active in the CD8(+) SP lineage. In this study, we show that the chromatin of the CD8 locus is remodeled in C57BL/6 and B6/J Rag1(-/-) MOM double-negative thymocytes as indicated by DNaseI hypersensitivity and widespread bivalent chromatin marks. Pre-TCR signaling coincides with chromatin bivalency resolution into monovalent activating modifications in double-positive and CD8 SP cells. Shortly after commitment to CD4 SP cell lineage, monovalent repressive characteristics and chromatin inaccessibility are established. Differential binding of Ikaros, NuRD, and heterochromatin protein 1α on the locus during these processes may participate in the complex regulation of CD8.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD4 Antigens / genetics
  • CD4 Antigens / immunology
  • CD4 Antigens / metabolism
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / metabolism
  • CD8 Antigens / genetics
  • CD8 Antigens / immunology*
  • CD8 Antigens / metabolism
  • CD8-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / metabolism
  • Cell Differentiation / immunology
  • Cell Line
  • Chromatin / genetics
  • Chromatin / immunology*
  • Chromatin / metabolism
  • Deoxyribonuclease I / metabolism
  • Flow Cytometry
  • Histones / metabolism
  • Ikaros Transcription Factor / metabolism
  • Mi-2 Nucleosome Remodeling and Deacetylase Complex / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Precursor Cells, T-Lymphoid / immunology
  • Precursor Cells, T-Lymphoid / metabolism
  • Protein Binding
  • Receptors, Antigen, T-Cell / immunology*
  • Signal Transduction / immunology
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • Thymus Gland / cytology
  • Thymus Gland / immunology*
  • Thymus Gland / metabolism
  • Time Factors

Substances

  • CD4 Antigens
  • CD8 Antigens
  • Chromatin
  • Histones
  • Receptors, Antigen, T-Cell
  • Zfpn1a1 protein, mouse
  • Ikaros Transcription Factor
  • Deoxyribonuclease I
  • Mi-2 Nucleosome Remodeling and Deacetylase Complex