Inflammasome-Independent NLRP3 Restriction of a Protective Early Neutrophil Response to Pulmonary Tularemia
Fig 5
An early neutrophil response in Nlrp3-/- mice is protective during pulmonary tularemia.
(A-E) Total numbers of CD11b+ myeloid cells, Ly6G+ neutrophils, polymorphonucleated-MDSC (pMDSC), F4/80+macrophages or mono-nucleated-MDSC (mMDSC) in LVS-infected lungs (mean ± SD of two independent experiments, n = 6 mice, Student’s t-test, *p<0.05 indicates difference from wildtype mice at specific dpi). (F) Survival of mice following Ft LVS (1000 cfu) infection and treatment with anti-Gr-1 antibody (200μg/mouse, i.p route) at -1 and 1 dpi (% survival of two experiments, n = 6 mice, Log-rank test, *p<0.05). (G) Total numbers of Ly6Ghigh neutrophils in lungs of mice following i.n. instillation of LPS and infected 48 h later with Ft LVS (1000 cfu) (mean ± SD of three mice, Student’s t-test, *p<0.05 and **p<0.01 indicate the difference from those mice receiving no LPS but infected with LVS). (H) Survival of mice following Ft LVS (1000 cfu) infection. Naïve mice were first adoptively transferred with PMN (1 x106 cells/mouse; isolated from bone marrow cells) or CD3+ T cells (1 x106 cells/mouse; isolated from spleen) by intratracheal intubation and infected with Ft LVS on the following day. Other groups of naïve mice were treated with LPS (100 or 10 μg/mouse, i.n instillation) to elicit PMN/myeloid cell response, infected with Ft LVS after 48 h, and monitored for survival and mortality (% survival of two independent experiment, n = 10 mice, Log-rank test, *p<0.05 or ***p<0.001 indicates difference from naïve mice infected with LVS alone). (I) Lung bacterial burden in mice receiving i.n. instillation of LPS and infected 48 h later with Ft LVS (1000 cfu) (mean ± SD of four mice, Student’s t-test, *p<0.05 and **p<0.01 indicate the difference from those mice receiving no LPS but infected with LVS). (J) Lung bacterial burden in mice receiving PMN or CD3+ T cells post-infection with Ft LVS (1000 cfu) (mean ± SD of four mice, Student’s t-test, *p<0.05 and **p<0.01). (K) Levels of IL-17, KC and MCP-1 in lung homogenates (mean ± SD of two independent experiments, n = 6 mice, Student’s t-test). (L) Survival of mice following Ft LVS (1000 cfu) infection and treatment with anti-IL-17 antibody (200μg/mouse, i.p route) at 1 and 3 dpi (% survival of two independent experiments, n = 8 mice, Log-rank test). (M) Total numbers of Ly6Ghigh neutrophils in lungs of wildtype and IL-1r-/- mice infected with lethal (1000 cfu) Ft LVS (mean ± SD of two independent experiments, n = 6 mice, Student’s t-test, *p<0.05 and **p<0.01).