Andreassen K, Bendiksen S, Kjeldsen E, Van Ghelue M, Moens U, Arnesen E, Rekvig OP. T cell autoimmunity to histones and nucleosomes is a latent property of the normal immune system.
ARTHRITIS AND RHEUMATISM 2002;
46:1270-81. [PMID:
12115233 DOI:
10.1002/art.10254]
[Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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.
Collapse