Identification of T-cell epitopes of autoantigens using recombinant proteins; studies on experimental autoimmune myasthenia gravis

• Published in: Immunology 1990-12, Vol.71 (4), p.538-543
• Main Authors: Zhang, Y, Frutiger, S, Hughes, G J, Savoy, M C, Barkas, T
• Format: Article
• Language: English
• Subjects: Animals; Autoantigens - immunology; Autoimmune Diseases - immunology; Cell Line; Chromatography, High Pressure Liquid; Epitopes - analysis; Female; Myasthenia Gravis - immunology; Rats; Rats, Inbred Lew; Receptors, Nicotinic - immunology; Recombinant Proteins - immunology; Species Specificity; T-Lymphocytes - immunology
• ISSN: 0019-2805; 1365-2567

In the Lewis rat, T-cell lines from animals immunized with native or denatured Torpedo nAChR recognize the Torpedo-derived recombinant protein T alpha X1 omega (alpha-2-200) but not the equivalent mouse- or chick-derived recombinant proteins X4 omega or C alpha X1 omega (alpha 6-216 and alpha 35-216, respectively). T-cell lines derived from animals immunized with T alpha X1 omega, X4 omega or C alpha X1 omega are specific for the homologous protein. This lack of cross-species reactivity suggests caution in the use of Torpedo nAChR-selected lines generated from human patients. Proteolysis and fractionation of the products by reverse-phase HPLC was effective in localization of a T-cell epitope of X4 omega, a mouse-derived recombinant protein. With Lewis rats, the major epitope of T alpha X1 omega is alpha 97-112. However, the major epitope of the mouse-derived protein, X4 omega, as determined by proteolytic digestion and fractionation of the products by reverse-phase HPLC, is alpha 14-22. This shift in T-cell epitope between closely related proteins may result from the conservation of sequence of alpha 97-112 between mammalian species.