Figure 4. IL-18 Acts on NK Cells to License IL-10 Secretion Independent of IL-12/STAT4 Signaling.
(A) Percentage of NK1.1+CD3− cells from the spleen, liver, and blood positive for IL-18R1 expression from IL-10 GFP+ and IL-10 GFP− populations at the indicated time points with 104 Lm i.v. in IL-10 GFP reporter mice (representative of n = 3 experiments with 3–5 mice per group).
(B) Serum IL-10 and Lm burdens per liver from B6 or B6.Il18R−/− mice sacrificed 72 hpi (n = 3 independent experiments pooled with 3–5 mice per group).
(C) Supernatant IL-10 detected in B6 or B6.Il18R−/− NK cells 72 hr after co-culture with B6.Il10−/− BMDCs stimulated with L1S+LPS or infected with Lm.
(D) Supernatant IL-10 detected from B6 or B6.Il18R−/− NK cells 72 hr after co-culture with or exposure to filtered supernatants from B6.Il10−/− BMDCs stimulated with L1S+LPS for 1 hr.
(E) Supernatant IFNγ detected in B6 or B6.Il18R−/− NK cells 24 hr after co-culture with B6 BMDCs stimulated with L1S+LPS.
(F and G) Supernatant cytokines detected 24 hr (IFNγ, F) or 72 hr (IL-10, G) in NK cells in co-culture with B6.Il10−/− BMDCs stimulated with L1S+LPS with or without 1 μg/mL anti-IL-12p70 or 50 μg/mL anti-IL-12R added with NK cells to co-cultures.
(H) Supernatant IL-10 detected 72 hr after stimulation of NK cells with 50 pg/mL rIL-12 + 50 pg/mL rIL-2 with or without 80 μM STAT4 inhibitor lisofylline.
(I) Supernatant IL-10 detected at 72 hr from NK cells in co-culture with B6.Il10−/− BMDCs stimulated with L1S+LPS or infected with Lm with or without 80 μM STAT4 inhibitor lisofylline added with NK cells to co-cultures.
(J) Supernatant IL-10 detected in B6 or B6.Il18R−/− NK cells 72 hr post-stimulation with 50 pg/mL rIL-12 + 50 pg/mL rIL-2 (n = 3 independent experiments pooled for in vitro experiments).
Data are displayed as mean ± SEM; *p < 0.05 and ***p < 0.001 as measured by t test.