Mechanisms of action of mAb 198. (A) Comparison of the proliferation of human muscle cells in the presence of anti-AChR antibodies or isotype control using CFSE. Fluorescence geometric means (GM) decreased with time but did not exhibit any differences when the cells were treated with anti-AChR mAb or isotype control (3 μ/ml). (B) Kinetics of IL-6 production by LHCNM2 after stimulation with mAb 198 anti-AChR antibody is represented in black, and mRNA expression is represented in grey. IL-6 production was measured by ELISA assays and normalized to isotype controls (n = 4 for each group and time). mRNA expression was measured by Q-RT-PCR and was normalized to GAPDH (n = 2 for each group and time). Mean ± SEM is represented.