Autoimmune T cell recognition of human acetylcholine receptor: the sites of T cell recognition in myasthenia gravis on the extracellular part of the alpha subunit.

Autoimmune T cell lines were prepared from peripheral blood lymphocytes of five myasthenia gravis patients by passage in vitro with an equimolar mixture of 18 overlapping synthetic peptides corresponding to the entire extracellular region (residues alpha 1-210) of the alpha subunit of human acetylcholine receptor (AChR). The proliferative responses of the human AChR-specific T cell lines to each of the individual peptides were determined. It was found that the profiles of the peptides recognized by the T cells were different among the five T cell lines, consistent with genetic control operating at the recognition site level. However, other regulatory influences may play important roles in the triggering of the autoimmune responses. These results suggest that the pathogenesis of this autoimmune disease is variable at the cellular-molecular level.