CaMK4 controls follicular helper T cell expansion and function during normal and autoimmune T-dependent B cell responses

作者：Marc Scherlinger, Hao Li, Wenliang Pan, Wei Li, Kohei Karino, Theodoros Vichos, Afroditi Boulougoura, Nobuya Yoshida, Maria Tsokos, George C. Tsokos · 发表于：Nature Communications · 年份：2024 · DOI：10.1038/s41467-024-45080-x · 被引用次数：21 · 研究领域：T-cell and B-cell Immunology、Immune Cell Function and Interaction、Systemic Lupus Erythematosus Research

Abstract Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by dysregulated B cell compartment responsible for the production of autoantibodies. Here, we show that T cell-specific expression of calcium/calmodulin-dependent protein kinase IV (CaMK4) leads to T follicular helper (T fh ) cells expansion in models of T-dependent immunization and autoimmunity. Mechanistically, CaMK4 controls the T fh -specific transcription factor B cell lymphoma 6 ( Bcl6 ) at the transcriptional level through the cAMP responsive element modulator α (CREMα). In the absence of CaMK4 in T cells, germinal center formation and humoral immunity is impaired in immunized mice, resulting in reduced anti-dsDNA titres, as well as IgG and complement kidney deposition in the lupus-prone B6. lpr mouse. In human T fh cells, CaMK4 inhibition reduced BCL6 expression and IL-21 secretion ex vivo, resulting in impaired plasmablast formation and IgG production. In patients with SLE, CAMK4 mRNA levels in T fh cells correlated with those of BCL6 . In conclusion, we identify CaMK4/CREMα as a driver of T cell-dependent B cell dysregulation in autoimmunity.