Effect of Panobacumab on Meropenem-resistant <i>P. aeruginosa</i> infection.

<p>After overnight preculture, <i>P. aeruginosa</i> strain 84 and 2310.55 were grew for 9 h in the presence or not of 1µg/mL of Meropenem. Optical density at 600nm was recorded over the period (A). B6 mice received intra-nasal instillation of 40 µL of Meropenem-resistant <i>P. aeruginosa</i> strain 84 (10⁷ cfu) (B and D) or classical strain 2310.55 (10⁶ cfu) (C and E). Meropenem or saline was given ip at 300 mg/kg, 2 h after the infection. Panobacumab was given i.v. at 0.4 mg/kg, 4 h after the infection, alone or in combination with Meropenem. Lung cfu (B and C) and lung weights (D and E) were recorded 24 h after the infection. Groups of 7 mice were used and mean values ±SEM are shown (One-way ANOVA with Tukey’s Multiple Comparison Test; ns: non significant, * p<0.05, ** p<0.01, *** p<0.001). The results are a pool of two independent experiments.</p

Enhanced survival after Panobacumab treatment in immunosuppressed <i>P. aeruginosa</i>-infected mice.

<p>B6 mice were immunosuppressed with cyclophosphamide (100 mg/kg) and 3 days later infected by intra-nasal instillation of 40 µL of <i>P. aeruginosa</i> strain 2310.55 (2x10⁵ cfu). Panobacumab was given i.v. at 0.4 mg/kg, 4 h after the infection. Survival was monitored 24 h after infection. Groups of 8-10 mice were used.</p

Reduced lung inflammation after Panobacumab treatment in immunosuppressed <i>P. aeruginosa-</i>infected mice.

<p>B6 mice were immunosuppressed with cyclophosphamide (100 mg/kg) and 3 days later infected by intra-nasal instillation of 40 µL of <i>P. aeruginosa</i> strain 2310.55 (2x10⁵ cfu). Panobacumab was given i.v. at 0.4 mg/kg, 4 h after the infection. Absolute numbers of cells (A), neutrophils (B) were measured in BALF 24 h after infection. Lung MPO (C) was recorded 24 h after infection. The concentrations of IL-6 (D) and IL-1β (E) in lung homogenates were determined 24 h after infection. Groups of 8-10 mice were used and mean values ± SEM are shown (One-way ANOVA with Tukey’s Multiple Comparison Test: * p<0.05, *** p<0.001). The results are a pool of two independent experiments.</p

Effect of Panobacumab on <i>P. aeruginosa</i> infection alone and in combination with antibiotic administration.

<p>B6 mice received intra-nasal instillation of 40 µL of <i>P. aeruginosa</i> strain 2310.55 (10⁶ cfu). Meropenem or saline was given ip at 30, 100 and 300 mg/kg, 2 h after the infection. Lung cfu (A) and lung weights (B) were recorded 24 h after the infection. Panobacumab or a control anti-LPS: O1 IgM MAb (Ctrl O1 MAb, with specificity to serotype O1) were given i.v. at 0.4 mg/kg, 4 h after the infection, alone or in combination with Meropenem, lung cfu (C) and lung weight (D) and lung cfu (B) were recorded 24 h after the infection. Groups of 8-25 mice were used and mean values ± SEM are shown (One-way ANOVA with Tukey’s Multiple Comparison Test; ns: non significant, * p<0.05, ** p<0.01, *** p<0.001). The results are a pool of three independent experiments.</p

Enhanced <i>P. aeruginosa</i>-induced pneumonia in cyclophosphamide immunosuppressed mice.

<p>Myelodepression by cyclophosphamide causes neutropenia and enhanced pneumonia. Total white blood cells (A), monocytes (B), granulocytes (C) and lymphocytes (D) were determined. B6 mice received intra-peritoneal injection of 200 µL of cyclophosphamide at 50, 100 and 200 mg/kg and the hematogram was analyzed at 3, 5 and 7 days. Separate groups of mice were infected 3 days after CP injection by intra-nasal instillation of 40 µL of <i>P. aeruginosa</i> strain 2310.55 (10⁵ or 10⁶ cfu). Lung cfu (A) and lung weight (B) were recorded 24 h after infection. Groups of 7 mice were used and mean values ± SEM are shown (One-way ANOVA with Tukey’s Multiple Comparison Test; * p<0.05, ** p<0.01, *** p<0.001). The results are representative of three independent experiments.</p

image_2_Interleukin-1α Mediates Ozone-Induced Myeloid Differentiation Factor-88-Dependent Epithelial Tissue Injury and Inflammation.tiff

<p>Air pollution associated with ozone exposure represents a major inducer of respiratory disease in man. In mice, a single ozone exposure causes lung injury with disruption of the respiratory barrier and inflammation. We investigated the role of interleukin-1 (IL-1)-associated cytokines upon a single ozone exposure (1 ppm for 1 h) using IL-1α-, IL-1β-, and IL-18-deficient mice or an anti-IL-1α neutralizing antibody underlying the rapid epithelial cell death. Here, we demonstrate the release of the alarmin IL-1α after ozone exposure and that the acute respiratory barrier injury and inflammation and airway hyperreactivity are IL-1α-dependent. IL-1α signaling via IL-1R1 depends on the adaptor protein myeloid differentiation factor-88 (MyD88). Importantly, epithelial cell signaling is critical, since deletion of MyD88 in lung type I alveolar epithelial cells reduced ozone-induced inflammation. In addition, intratracheal injection of recombinant rmIL-1α in MyD88^acid mice led to reduction of inflammation in comparison with wild type mice treated with rmIL-1α. Therefore, a major part of inflammation is mediated by IL-1α signaling in epithelial cells. In conclusion, the alarmin IL-1α released upon ozone-induced tissue damage and inflammation is mediated by MyD88 signaling in epithelial cells. Therefore, IL-1α may represent a therapeutic target to attenuate ozone-induced lung inflammation and hyperreactivity.</p

Histological changes in liver upon DENV-2 infection in mice.

<p>WT or KO mice were infected i.p. with 10 LD₅₀ of DENV-2 and then sacrificed at day 6 for tissue samples. Hematoxylin & Eosin stained liver sections from non-infected and DENV-2 infected WT, CCR1^–/–, CCR2^–/– and CCR4^–/– mice, showing different degrees of congestion, hemorrhage, hepatocyte degeneration and necrosis. Each slide presented in the panel is representative of at least 10 different fields (n = 5–6 mice). Magnification: 400X.</p

Characterization of infected cells expressing CD11c, CD205 and MOMA-1 in the spleen of IL12p40-deficient BALB/c mice.

<p>IL12p40^-/- STAT6^+/+ BALB/c mice were injected i.n. with 2x10⁷ CFU of mCherry-Br. The mice were sacrificed at 28 days post-infection and the spleens were collected and examined by immunohistofluorescence. <b>A</b>, The left panel shows mCherry-Br co-localization with cells expressing CD11c. The middle panel shows mCherry-Br co-localization with cells expressing CD205 and the right panel shows co-localization of CD11c- and CD205-expressing cells. <b>B</b>, The upper panels show distribution of MOMA-1-expressing cells and co-localization with mCherry-Br (left), distribution of DEC205-expressing cells and co-localization with mCherry-Br (middle), and co-localization of MOMA-1- and CD205-expressing cells (right). The panels below are higher magnification views of the same stainings. The panels are color-coded with the text for phalloidin, the antigen examined or mCherry-Br. Scale bar = 50 and 20 μm, as indicated. r.p.: red pulp; w.p.: white pulp. Yellow arrowheads indicate the presence of bacteria. The data are representative of at least two independent experiments.</p

Course of <i>B</i>. <i>melitensis</i> infection in organs of wild-type (wt), STAT6-, IL12p40- and STAT6/IL12p40-deficient BALB/c mice.

<p>The mice were injected intranasally (i.n.) with 2x10⁷ CFU of mCherry-Br <i>B</i>. <i>melitensis</i> and sacrificed at the indicated times. The data represent the number of CFU per gram of lung, spleen and liver. Grey bars represent the medians. “n” is the number of mice used. These results are representative of at least two independent experiments. ns, non-significant.</p

image_1_Interleukin-1α Mediates Ozone-Induced Myeloid Differentiation Factor-88-Dependent Epithelial Tissue Injury and Inflammation.tiff

<p>Air pollution associated with ozone exposure represents a major inducer of respiratory disease in man. In mice, a single ozone exposure causes lung injury with disruption of the respiratory barrier and inflammation. We investigated the role of interleukin-1 (IL-1)-associated cytokines upon a single ozone exposure (1 ppm for 1 h) using IL-1α-, IL-1β-, and IL-18-deficient mice or an anti-IL-1α neutralizing antibody underlying the rapid epithelial cell death. Here, we demonstrate the release of the alarmin IL-1α after ozone exposure and that the acute respiratory barrier injury and inflammation and airway hyperreactivity are IL-1α-dependent. IL-1α signaling via IL-1R1 depends on the adaptor protein myeloid differentiation factor-88 (MyD88). Importantly, epithelial cell signaling is critical, since deletion of MyD88 in lung type I alveolar epithelial cells reduced ozone-induced inflammation. In addition, intratracheal injection of recombinant rmIL-1α in MyD88^acid mice led to reduction of inflammation in comparison with wild type mice treated with rmIL-1α. Therefore, a major part of inflammation is mediated by IL-1α signaling in epithelial cells. In conclusion, the alarmin IL-1α released upon ozone-induced tissue damage and inflammation is mediated by MyD88 signaling in epithelial cells. Therefore, IL-1α may represent a therapeutic target to attenuate ozone-induced lung inflammation and hyperreactivity.</p