AS2863619 (1 μM; 22 hours; mouse CD4+ T cells) treatment suppresses serine phosphorylation of the PSP motif of STAT5b to ~40% while enhancing tyrosine phosphorylation in the C-terminal domain to ~160% of control-treated samples.

AS2863619 (30 mg/kg; p.o.; daily; for 2 weeks; mice) treatment after sensitization with DNFB dampens the degree of the secondary response, with milder infiltration of inflammatory cells into the skin and decreases ratios of IFN-γ+ cells in a skin contact hypersensitivity model, when compared with vehicle-treated control mice. Treg depletion before the elicitation of the secondary response abolishes AS2863619-induced suppression. KLRG1+ Foxp3+ T cells are specifically increased in DNFB sensitized AS2863619-treated mice.