Abstract
Background Autoimmune disease is a systemic inflammatory response with autoantibodies. We investigated anti-microbial antibodies in Crohn’s disease (CD), and Sjogren’s syndrome (SS) and their roles in pathogenesis of these autoimmune diseases.
Methods Western blot was used to determine the reactivity of the plasmas from patients with CD and SS as primary antibodies against the whole microbial extracts. The microbial proteins reactive to patients’ plasmas were identified and the modified ELISA assays were used to determine the blood levels of antibodies against these microbial proteins in patients with CD and SS. Antibodies against the microbial proteins are used for immunohistochemical staining of normal human tissue.
Interpretation A group of 7 microbial proteins were identified reactive to the plasmas of patients with CD and SS including DNA-directed RNA polymerase B (RPOB), and elongation factor G (EF-G) from Staphylococcus aureus and Staphylococcus pseudintermedius (S. aureus and S. pseudintermedius), ATP synthase alpha and heat shock protein 65 (Hsp65) from Mycobacterium avium subspecies paratuberculosis (MAP), elongation factor Tu (EF-Tu) and outer membrane porin C (ompC) from Escherichia Coli (E. coli). One unknown protein from S. aureus is also identified. Anti-microbial antibodies can cross-react with human tissues. The antibody levels against these microbial proteins are significantly elevated in the patients with CD and SS. The presence of anti-microbial antibodies indicates the failure of the innate immunity and the cross-reactivity of the anti-microbial antibodies to human tissue provides a new mechanism of pathogenesis of autoimmune diseases such as CD and SS.
Funding PZM Diagnostics, LLC.