T cell autoimmunity to histones and nucleosomes is a latent property of the normal immune system

Arthritis Rheum. 2002 May;46(5):1270-81. doi: 10.1002/art.10254.

Abstract

Objective: Investigators in this study undertook to determine whether in vitro antigen-responsive immune (polyomavirus T antigen [T-ag]- specific) and autoimmune (histone-specific) T cells from normal individuals share structural and genetic characteristics with those from patients with systemic lupus erythematosus (SLE).

Methods: Histone-specific T cells were generated by stimulation of peripheral blood mononuclear cells (PBMCs) with nucleosome-T-ag complexes and were subsequently maintained by pure histones. T-ag-specific T cell clones were initiated and maintained by T-ag. The frequencies of circulating histone- and T-ag-specific T cells were determined in healthy individuals and in SLE patients by limiting dilution of PBMCs. T cell receptor (TCR) gene usage and variable-region structures were determined by complementary DNA sequencing. These sequences were compared between T-ag- and histone-specific T cells and between normal individuals and SLE patients for each specificity.

Results: Individual in vitro-expanded histone- and T-ag-specific T cells from normal individuals displayed identical TCR V(alpha) and/or V(beta) chain third complementarity-determining region (CDR3) sequences, indicating that they were clonally expanded in vivo. The frequencies of in vitro antigen-responsive T-ag- or histone-specific T cells from normal individuals were similar to those from SLE patients. Although heterogeneous for variable-region structure and gene usage, histone-specific T cells from healthy individuals and SLE patients selected aspartic and/or glutamic acids at positions 99 and/or 100 of the V(beta) CDR3 sequence.

Conclusion: Autoimmune T cells from healthy individuals can be activated by nucleosome- T-ag complexes and maintained by histones in vitro. Such T cells possessed TCR structures similar to those from SLE patients, demonstrating that T cell autoimmunity to nucleosomes may be a latent property of the normal immune system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amino Acids / genetics
  • Autoantigens / immunology
  • Autoimmunity / genetics
  • Autoimmunity / immunology*
  • Cell Line
  • Cloning, Molecular
  • Complementarity Determining Regions / genetics
  • Female
  • Histones / immunology*
  • Humans
  • Immune System / immunology*
  • Immunoglobulin Variable Region / genetics
  • In Vitro Techniques
  • Lupus Erythematosus, Systemic / genetics
  • Lupus Erythematosus, Systemic / immunology
  • Middle Aged
  • Nucleosomes / immunology*
  • Receptors, Antigen, T-Cell, alpha-beta / genetics
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology*

Substances

  • Amino Acids
  • Autoantigens
  • Complementarity Determining Regions
  • Histones
  • Immunoglobulin Variable Region
  • Nucleosomes
  • Receptors, Antigen, T-Cell, alpha-beta