Tropomyosin isoforms in intestinal mucosa: production of autoantibodies to tropomyosin isoforms in ulcerative colitis

Gastroenterology. 1998 May;114(5):912-22. doi: 10.1016/s0016-5085(98)70310-5.


Background & aims: Autoantibodies against tropomyosins (TMs) have been reported in ulcerative colitis (UC). In this study the hTM isoforms (hTM1-5) present in intestinal epithelial cells and in smooth muscle were investigated, and the immunoreactivity against hTMs by immunoglobulin G (IgG) produced in vitro by colonic mucosal lymphocytes (LPMCs) from patients with UC, Crohn's disease (CD), and controls was examined.

Methods: TMs were extracted from colonic and jejunal epithelial cells and smooth muscle, and hTM isoforms were identified using isoform-specific monoclonal antibodies by enzyme-linked immunosorbent assay and transblot analysis. The immunoreactivity of IgG produced by colonic LPMCs was analyzed against the recombinant hTM isoforms.

Results: The major hTM isoforms present in colonic and jejunal epithelial cells are hTM5 and hTM4, whereas intestinal smooth muscle contains the hTM1-3 isoforms. The IgG synthesized in vitro by LPMCs from UC (n = 19) recognized hTM5 and hTM1, more significantly (P < 0.04 to <0.001) when compared with CD (n = 12) and controls (n = 17). However, IgG produced by LPMCs from CD did not show such anti-hTM reactivity. Mucosal anti-hTM IgG mainly belonged to the IgG1 subclass.

Conclusions: Intestinal epithelial cells and smooth muscle have distinct hTM isoforms. Patients with UC, and not CD, show mucosal autoantibody response against hTM isoforms, particularly hTM5 and hTM1.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Antibodies / analysis
  • Autoantibodies / immunology*
  • Colitis, Ulcerative / immunology*
  • Colitis, Ulcerative / metabolism
  • Colitis, Ulcerative / pathology
  • Crohn Disease / immunology
  • Crohn Disease / metabolism
  • Crohn Disease / pathology
  • Female
  • Humans
  • Immunoglobulin G / metabolism
  • Intestinal Mucosa / metabolism*
  • Intestinal Mucosa / pathology
  • Isomerism
  • Male
  • Middle Aged
  • Reference Values
  • Tropomyosin / immunology*
  • Tropomyosin / metabolism*


  • Antibodies
  • Autoantibodies
  • Immunoglobulin G
  • Tropomyosin