Enrichment of Scleroderma Vascular Disease-Associated Autoantigens in Endothelial Lineage Cells

Arthritis Rheumatol. 2016 Oct;68(10):2540-9. doi: 10.1002/art.39743.


Objective: Scleroderma patients with autoantibodies to CENPs and/or interferon-inducible protein 16 (IFI-16) are at increased risk of severe vascular complications. This study was undertaken to determine whether these autoantigens are enriched in cells of the vasculature.

Methods: Successive stages of embryoid bodies (EBs) as well as vascular progenitors were used to evaluate the expression of scleroderma autoantigens IFI-16 and CENP by immunoblotting. CD31 was included to mark early blood vessels. IFI-16 and CD31 expression were defined in paraffin-embedded skin sections from scleroderma patients and from healthy controls. IFI-16 expression was determined by flow cytometric analysis in circulating endothelial cells (CECs) and circulating hematopoietic progenitor cells.

Results: Expression of CENP-A, IFI-16, and CD31 was enriched in EBs on days 10 and 12 of differentiation, and particularly in cultures enriched in vascular progenitors (IFI-16, CD31, and CENPs A and B). This pattern was distinct from that of comparator autoantigens. Immunohistochemical staining of paraffin-embedded skin sections showed enrichment of IFI-16 in CD31-positive vascular endothelial cells in biopsy specimens from scleroderma patients and normal controls. Flow cytometric analysis revealed IFI-16 expression in circulating hematopoietic progenitor cells but minimal expression in CECs.

Conclusion: Our findings indicate that expression of the scleroderma autoantigens IFI-16 and CENPs, which are associated with severe vascular disease, is increased in vascular progenitors and mature endothelial cells. High level, lineage-enriched expression of autoantigens may explain the striking association between clinical phenotypes and the immune targeting of specific autoantigens.

Publication types

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

MeSH terms

  • Autoantigens / immunology*
  • Autoantigens / metabolism
  • Case-Control Studies
  • Cell Lineage
  • Centromere Protein A
  • Centromere Protein B / immunology*
  • Centromere Protein B / metabolism
  • Chromosomal Proteins, Non-Histone / immunology*
  • Chromosomal Proteins, Non-Histone / metabolism
  • Embryoid Bodies / immunology*
  • Embryoid Bodies / metabolism
  • Endothelial Cells / immunology*
  • Endothelial Cells / metabolism
  • Endothelial Progenitor Cells / immunology*
  • Endothelial Progenitor Cells / metabolism
  • Flow Cytometry
  • Hematopoietic Stem Cells / immunology
  • Hematopoietic Stem Cells / metabolism
  • Humans
  • Immunoblotting
  • Immunohistochemistry
  • Leukocytes, Mononuclear
  • Nuclear Proteins / immunology*
  • Nuclear Proteins / metabolism
  • Phosphoproteins / immunology*
  • Phosphoproteins / metabolism
  • Platelet Endothelial Cell Adhesion Molecule-1 / metabolism
  • Scleroderma, Diffuse / immunology
  • Scleroderma, Diffuse / metabolism
  • Scleroderma, Limited / immunology
  • Scleroderma, Limited / metabolism
  • Scleroderma, Systemic / immunology*
  • Scleroderma, Systemic / metabolism
  • Skin / immunology
  • Skin / metabolism


  • Autoantigens
  • CENPA protein, human
  • CENPB protein, human
  • Centromere Protein A
  • Centromere Protein B
  • Chromosomal Proteins, Non-Histone
  • Nuclear Proteins
  • Phosphoproteins
  • Platelet Endothelial Cell Adhesion Molecule-1
  • IFI16 protein, human