Journal of Clinical Endocrinology & Metabolism, Vol 74, 732-736, Copyright © 1992 by Endocrine Society

ARTICLES

Cell surface localization of a 72 kilodalton heat shock protein in retroocular fibroblasts from patients with Graves' ophthalmopathy

AE Heufelder, BE Wenzel and RS Bahn
Department of Internal Medicine, Mayo Clinic/Foundation, Rochester, Minnesota 55905.

Heat shock proteins (HSPs) have been implicated in autoimmune disease, although they are generally considered to be intracellular in location. We demonstrate that, under certain circumstances, the inducible intracellular 72 kilodalton HSP can also be detected on the surface of cells. We used cultured retroocular fibroblasts derived from patients with severe Graves' ophthalmopathy (GO) and normal individuals in our studies. Sodium dodecylsulfate polyacrylamide-gel electrophoresis of immunoprecipitated cell lysates, derived from surface-radioiodinated GO cell monolayers, resulted in a single band of appropriate molecular weight on the autoradiogram. Further, a bright cell surface staining pattern was observed when indirect immunofluorescence was performed using the same anti-HSP 72 monoclonal antibody on parallel cell cultures. No cell-surface HSP 72 reactivity was detected in normal retroocular fibroblast monolayers by either method. These results are the first demonstration, by immunoprecipitation of surface-labeled proteins, of HSP expression on the surface of cells. This localization of HSP 72 on the surface of affected cells obtained from patients with an autoimmune disease may have implications concerning the role of this molecule in autoimmunity in general, and particularly in the immune process of GO.

This article has been cited by other articles:

				R. S. Bahn and A. E. Heufelder Pathogenesis of Graves' Ophthalmopathy N. Engl. J. Med., November 11, 1993; 329(20): 1468 - 1475. [Full Text]