Autoantibodies to tyrosinase-related protein-1 detected in the sera of vitiligo patients using a quantitative radiobinding assay.

Abstract

In the present study, we describe the in vitro transcription-translation of human tyrosinase-related protein-1 (TRP-1) cDNA and subsequent use of the resulting 35S-labelled TRP-1 in a radioimmunoassay to analyse vitiligo sera for the presence of TRP-1 antibodies. Of 53 vitiligo sera examined in the assay, three (5.7%) were found to be positive for TRP-1 antibodies. In contrast, sera from 20 controls, 10 patients with Hashimoto's thyroiditis and 10 patients with Graves' disease were all negative for TRP-1 antibodies. Although glycosylation of the labelled protein was necessary for its immunoprecipitation by TRP-1-specific monoclonal antibody TA99, this post-translational processing did not affect the binding of any of the sera tested. All three patients positive for TRP-1 antibodies (aged 50-63 years) had had vitiligo of the symmetrical type for more than 1 year, and all of them also had an associated autoimmune disorder: Graves' disease in one and autoimmune hypothyroidism in two. In addition, antibodies to the melanogenic enzymes tyrosinase and tyrosinase-related protein-2 (TRP-2) were present in their serum. Absorption studies indicated that preincubation with COS-7 cell extract containing either expressed TRP-1, tyrosinase or TRP-2 absorbed out the immunoreactivity of the three sera positive in the radioimmunoassay (RIA) with [35S]TRP-1. The results indicate that autoantibodies to TRP-1 cross-react with tyrosinase and TRP-2, suggesting one or more common epitopes between the three proteins.

• Authors: E H Kemp, E A Waterman, D J Gawkrodger, P F Watson, A P Weetman
• Journal: The British journal of dermatology (Br J Dermatol) Vol. 139 Issue 5 Pg. 798-805 (Nov 1998) ISSN: 0007-0963 [Print] England
• PMID: 9892944 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Autoantibodies
• DNA, Complementary
• Membrane Glycoproteins
• Proteins
• Oxidoreductases
• TYRP1 protein, human
• tyrosinase-related protein-1
• Monophenol Monooxygenase

Topics

• Adolescent
• Adult
• Aged
• Autoantibodies (blood)
• DNA, Complementary (genetics)
• Electrophoresis, Polyacrylamide Gel
• Female
• Graves Disease (immunology)
• Humans
• Male
• Membrane Glycoproteins
• Middle Aged
• Monophenol Monooxygenase (immunology)
• Oxidoreductases
• Protein Biosynthesis
• Proteins (genetics, immunology)
• Radioimmunoassay
• Thyroiditis, Autoimmune (immunology)
• Transcription, Genetic
• Vitiligo (immunology)