Longitudinal omics reveals immune repertoire remodeling in myasthenia gravis patients post-tacrolimus therapy

Myasthenia gravis (MG) is a T/B cell-driven autoimmune disease. The immunomodulatory mechanisms of the common immunosuppressant tacrolimus (TAC) on the immune repertoire are unclear. This study investigated TAC's immunomodulatory effects via high-throughput sequencing of peripheral blood mononuclear cells from four MG patients pre- and post-four months of TAC monotherapy, revealing dynamic T-cell receptor (TCR) and B-cell receptor (BCR) repertoire remodeling. The immune repertoire of MG patients was characterized by a skewed usage of TRBV gene families compared to healthy controls, indicating an underlying immune dysfunction. Longitudinal analysis post-TAC therapy revealed potential downregulation of IGHV1-69 and IGHV3-43 gene frequencies (p < 0.05, FDR > 0.1), alongside non-significant trends toward shorter CDR3 lengths and reduced clonal diversity in both IGH and TRB (p > 0.05). The BCR repertoire underwent greater dynamic remodeling, while the TCR repertoire remained relatively stable, as evidenced by the persistence of dominant clones and overlapping TRB clones. BCR diversity and V or J gene usage in TCR and BCR showed potential associations with clinical severity. These data reveal skewed antigen recognition profiles in MG pathogenesis, with TAC orchestrating multimodal immunomodulation through peripheral immune repertoire reshaping.