title: Amphipathic segment of the nicotinic receptor alpha subunit contains epitopes recognized by T lymphocytes in myasthenia gravis.
abstract: Autoimmune helper T lymphocytes were selected from the blood of two myasthenic patients of different HLA-DR type, using acetylcholine receptor (AChR) from Torpedo californica. These polyclonal T cell lines were tested for reactivity with three synthetic peptides corresponding to the NH2-terminal region of the human AChR alpha subunit. This segment is a good candidate for T cell epitopes since it has a propensity to form an amphipathic alpha helix. The peptides elicited 10-30% of the response induced by native Torpedo AChR. Different peptides were recognized by the autoreactive T cells of the two patients. These results suggest that the NH2-terminal region of the AChR alpha chain contains T cell-stimulating epitopes, and that the T cell autoimmune response in myasthenia gravis, like the B cell response, is heterogeneous.
mesh_terms: D000328:Adult; D002469:Cell Separation; D000939:Epitopes / Q000276:immunology / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D009157:Myasthenia Gravis / Q000276:immunology / Q000378:metabolism*; D011978:Receptors, Nicotinic / Q000276:immunology / Q000302:isolation & purification*; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*
chemical_list: D000939:Epitopes; D011978:Receptors, Nicotinic