Du är här

Biochemical and immuno-pathological aspects of tissue transglutaminase in coeliac disease

Författare:
Publiceringsår: 2003
Språk: Engelska
Sidor: 221-226
Publikation/Tidskrift/Serie: Autoimmunity
Volym: 36
Nummer: 4
Dokumenttyp: Artikel
Förlag: Taylor and Francis Ltd

Sammanfattning

Tissue transglutaminase (tTg) has been identified as the major autoantigen in coeliac disease (CD). ELISA methods have been developed for measuring the autoantibody. There are divergent reports on the effects of calcium on the antibody binding to tTg. Furthermore, zinc is a potent inhibitor of tTg. To better understand the role of transglutaminase in CD, we have studied the stability of commercial tTG, the effect of CD serum on tTg-activity and the effects of calcium and zinc on the antibody binding. The inclusion of calcium during the coating of the ELISA plates significantly increases the binding of the antibody, while zinc at physiological concentrations inhibits the binding. Moreover, our results show that commercial guinea pig liver Tg treated with calcium contains at least four major antigenic molecules and is a labile enzyme, which is degraded rapidly by contaminating proteases. Human serum contains anti-proteases that protect the enzyme. Probably, the labile character of commercial tTG explains the divergent reports on the effects of calcium on antibody binding. Finally, antibodies in serum from a CD patient do not seem to inhibit tTg activity. Hypothetically, low, intestinal Zn2+ -levels facilitate Ca2+ -activation of tTg, which deamidates gliadin. A complex between tTg and modified gliadin forms the antigen and triggers the immune reaction leading to manifest CD. Hypozincaemia secondary to villous atrophy aggravates the induced disease.

Disputation

Nyckelord

  • Medicine and Health Sciences
  • thioester
  • calcium
  • zinc
  • coeliac
  • transglutaminase
  • activity staining

Övriga

Published
Yes
  • ISSN: 0891-6934

Box 117, 221 00 LUND
Telefon 046-222 00 00 (växel)
Telefax 046-222 47 20
lu [at] lu [dot] se

LERU logotype U21 logotype

Fakturaadress: Box 188, 221 00 LUND
Organisationsnummer: 202100-3211
Om webbplatsen