Evaluation of topoisomerase-1-specific CD8+ T-cell response in systemic sclerosis

Ann N Y Acad Sci. 2005 Dec;1062:137-45. doi: 10.1196/annals.1358.016.


Measurement of disease activity in systemic autoimmune disorders is often unreliable, and immunosuppressive therapy is often titrated to crude clinical response and/or onset of complications. Systemic sclerosis (SSc) presents a distinct clinical phenotype associated with specific autoantibodies. Anti-topoisomerase-1 (SCL-70) is selectively detected in 30-60% of subjects with diffuse skin and interstitial lung involvement. Such patients offer an ideal clinical model to characterize and quantify the autoantigen-specific T-cell response and its correlation with disease phenotype and activity. Human leukocyte antigen A2 (HLA-A2)-restricted topo-1 peptides were selected based on an epitope prediction algorithm. For initial studies, the best binder topo-1(262-270) KMLDHEYTT (#262) was used alone or loaded onto an artificial antigen-presenting platform generated by coupling a dimeric major histocompatibility complex-immunoglobulin G fusion protein (HLA-A2-Ig) and anti-CD28 antibodies onto magnetic beads (artificial antigen-presenting cells). Blood samples (100 microL) from HLA-A2+ SSc patients and cytomegalovirus (CMV) seropositive healthy control subjects were tested in an intracellular cytokine staining assay. Gamma interferon production by CD8+ T cells was measured after stimulation with peptide #262, CMVpp65, or MART-1 (irrelevant peptide). In two of five SCL-70+ patients, peptide #262-loaded aAPCs induced a specific CD8+ T-cell response (0.45% +/- 0.23% of total CD8+ cells). This response was not observed in the seven SCL-70- (five SSc and two CMV+) control subjects studied (0.03% +/- 0.02%). Interestingly, bronchoalveolar lavage fluid obtained from one topo-1-responsive SSc patient who had worsening respiratory function and active alveolitis showed striking enrichment of topo-1-specific CD8+ T cells (3.94%). This small-volume ex vivo assay may prove to be a sensitive and specific tool to assess disease activity and to monitor response to therapy in patients with scleroderma.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autoimmune Diseases / enzymology
  • Autoimmune Diseases / immunology
  • Bronchoalveolar Lavage Fluid / cytology
  • Bronchoalveolar Lavage Fluid / immunology
  • CD8-Positive T-Lymphocytes / enzymology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Case-Control Studies
  • DNA Topoisomerases, Type I / blood
  • DNA Topoisomerases, Type I / immunology*
  • Epitopes, T-Lymphocyte / immunology*
  • Humans
  • Lymphocyte Count
  • Phosphoproteins / immunology
  • Scleroderma, Systemic / enzymology*
  • Scleroderma, Systemic / immunology*
  • Viral Matrix Proteins / immunology


  • Epitopes, T-Lymphocyte
  • Phosphoproteins
  • Viral Matrix Proteins
  • cytomegalovirus matrix protein 65kDa
  • DNA Topoisomerases, Type I