JAK1 and JAK2 inhibition differentially ameliorate CpG/αIL-10R-induced activation and accumulation of splenic monocytes and neutrophils, as well as serum cytokine levels. (A) Proportions and numbers of total Ly6C⁺CD11b⁺ splenic monocytes and (B) CD80+ splenic monocytes in naïve mice or CpG+aIL10R treated mice treated with vehicle, itacitinib (120 mg/kg bid), fedratinib (60 mg/kg bid), or ruxolitinib (90 mg/kg bid) from days 4 to 8 after the first CpG+aIL10R injection. Analysis was performed on day 9. Proportions and absolute numbers of total Ly6G⁺CD11b⁺ splenic neutrophils (C) and CD80⁺ splenic neutrophils (D). (E-L) Serum cytokine levels. Data points represent single mice from 3 pooled experiments. ∗P < .05, ∗∗P < .01, ∗∗∗P < .001, or ∗∗∗∗P < .0001 by pairwise comparison.