Identification of Protein's Complementary to the Autoantigen Proteinase 3 and Their Involvement in the Pathogenesis of Autoimmune Disease Public Deposited

Downloadable Content

Download PDF
Last Modified
  • March 19, 2019
  • Bautz, David
    • Affiliation: School of Medicine, Department of Biochemistry and Biophysics
  • Previous work by our research group showed that PR3-ANCA patients had an antibody response to a recombinant complementary-PR3 protein encoded by the antisense strand of the PR3 mRNA. To follow up on this work, we sought to determine whether the patients also had a T cell response to this recombinant complementary-PR3 protein and whether a protein reactive with those antibodies could be identified in vivo. Chapter 2 of the dissertation describes the identification of CD4+ TH1 cells that proliferate in response to a complementary-PR3 peptide. This proliferation was seen by both a CFSE assay as well as by interferon-γ production in an ELISPOT assay. Those patients who had a T cell response to complementary-PR3 peptide also had antibodies to the complementary-PR3 protein. We next sought to determine if complementary-PR3 proteins could be identified from patient plasmapheresis material. Chapter 3 of this dissertation describes the identification of two complementary-PR3 proteins, human plasminogen and Protein F, a protein from pseudomonas. These proteins reacted with an antibody raised to a peptide encoded by the antisense RNA of the PR3 gene. As complementary proteins are known to interact, plasminogen was shown to be a substrate of PR3, indicative of interaction between the two proteins. Lastly, the anti-complementary PR3 antibodies also bound to normal human leukocytes, cells that are known to bind plasminogen on their surface. Chapter 4 describes the identification of anti-plasminogen autoantibodies in PR3-ANCA positive patients. These antibodies were purified using a complementary-PR3 peptide column, indicating that the anti-cPR3 and anti-plasminogen antibodies are the same. The anti-plasminogen antibodies bound a surface-exposed loop on plasminogen's catalytic domain. Two in vitro assays confirmed the antibodies affect on plasminogen activity. Serological screening of sera indicated that the anti-plasminogen autoantibodies were more prevalent in those PR3-ANCA patients with a clinical history of venous thrombotic events. By designing an experimental approach that considered protein complementarity, a previously unknown autoantigen and its pathogenic autoantibodies were identified. Consideration of complementary proteins can be used to discover other, and perhaps proximal, autoantigens and autoantibodies in other autoimmune diseases.
Date of publication
Resource type
Rights statement
  • In Copyright
  • Chaney, Stephen
  • Preston, Gloria A.
  • Kuhlman, Brian
  • Tropsha, Alexander
  • Falk, Ronald J.
  • Doctor of Philosophy
Degree granting institution
  • University of North Carolina at Chapel Hill Graduate School
Graduation year
  • 2008
  • This item is restricted from public view for 6 months after publication.

This work has no parents.