AhR-ROR-γt complex is a therapeutic target for MAP4K3/GLKhighIL-17Ahigh subpopulation of systemic lupus erythematosus

The cytokine IL-17A plays critical roles in the pathogenesis of autoimmune diseases. The frequencies of MAP kinase kinase kinase kinase 3 [also named germinal center kinase-like kinase (GLK)]-overexpressing T cells are correlated with disease severity of systemic lupus erythematosus (SLE). T-cell-specific GLK-transgenic mice develop spontaneous autoimmune responses through IL-17A. GLK signaling selectively stimulates IL-17A production in murine T cells through inducing aryl hydrocarbon receptor (AhR)-retinoic acid receptor-related orphan nuclear receptor-gamma t (ROR-gamma t) complex formation. Here, we investigated whether GLK-induced AhR-ROR-gamma t complex in T cells is a therapeutic target for human SLE. The population of GLK(+)IL-17A(+) T cells was enhanced in the peripheral blood from patients with SLE compared with that of healthy controls using flow cytometry. The receiver operating characteristic curve analysis showed that increased GLK(+)IL-17A(+) T-cell population in peripheral blood reflected an active stage of SLE. In addition, peripheral blood T cells from patients with SLE displayed induction of ROR-gamma t phosphorylation and the AhR-ROR-gamma t (and AhR-phosphorylated ROR-gamma t) complex. Moreover, we identified a small-molecule inhibitor, verteporfin, that inhibited GLK kinase activity and AhR-ROR-gamma t interaction. The small-molecule inhibitor verteporfin suppressed the disease severity in autoimmune mouse models and IL-17A production in T cells from patients with SLE. Collectively, the GLK-induced AhR-ROR-gamma t (and AhR-phosphorylated ROR-gamma t) complex is a therapeutic target for the GLK(high)IL-17A(high) subpopulation of human patients with SLE.-Chuang, H.-C., Chen, Y.-M., Chen, M.-H., Hung, W.-T., Yang, H.-Y., Tseng, Y.-H., Tan, T.-H. AhR-ROR-gamma t complex is a therapeutic target for MAP4K3/GLK(high)IL-17A(high) subpopulation of systemic lupus erythematosus.