CHARACTERIZATION OF ANTIACETYLCHOLINE RECEPTOR (ACHR) ANTIBODIES FROM MICE DIFFERING IN SUSCEPTIBILITY FOR EXPERIMENTAL AUTOIMMUNE MYASTHENIA-GRAVIS (EAMG)

In the murine model for EAMG we investigated the relation between disease susceptibility and fine specificity of anti-AChR antibodies obtained from high susceptible C57Bl/6 and low susceptible BALB/c mice after immunization with Torpedo acetylcholine receptor (tAChR). Anti-AChR MoAbs with fine specificity for the main immunogenic region (MIR), the alpha-bungarotoxin (alpha-BT)/acetylcholine binding sites and other extra- and intracellular epitopes were isolated from both mouse strains. In total, nine out of 38 MoAbs obtained from C57Bl/6 mice were directed against extracellular epitopes on mouse AChR in contrast to only one out of 27 MoAbs from BALB/c mice. A difference in antibody repertoire may underlie the difference in pathogenic response observed between these mouse strains. These results indicate that strain-specific differences in disease susceptibility in murine EAMG may be related to differences in the available repertoire of potential pathogenic antibodies.