Figure 1.
Enhanced P. aeruginosa-induced pneumonia in cyclophosphamide immunosuppressed mice.
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 P. aeruginosa 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.
Figure 2.
Therapeutic and specific effect of Panobacumab on P. aeruginosa-induced pneumonia in immunosuppressed mice.
B6 mice were immunosuppressed with cyclophosphamide (100 mg/kg) and 3 days later infected by intra-nasal instillation of 40 µL of P. aeruginosa strain 2310.55 (2x105 cfu). 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. Lung cfu (A) and lung weight (B) were recorded 24 h after the infection. Groups of 14 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.
Figure 3.
Reduced lung inflammation after Panobacumab treatment in immunosuppressed P. aeruginosa-infected mice.
B6 mice were immunosuppressed with cyclophosphamide (100 mg/kg) and 3 days later infected by intra-nasal instillation of 40 µL of P. aeruginosa 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.
Figure 4.
Enhanced survival after Panobacumab treatment in immunosuppressed P. aeruginosa-infected mice.
B6 mice were immunosuppressed with cyclophosphamide (100 mg/kg) and 3 days later infected by intra-nasal instillation of 40 µL of P. aeruginosa 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.
Figure 5.
Effect of Panobacumab on P. aeruginosa infection alone and in combination with antibiotic administration.
B6 mice received intra-nasal instillation of 40 µL of P. aeruginosa 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.
Figure 6.
Effect of Panobacumab on Meropenem-resistant P. aeruginosa infection.
After overnight preculture, P. aeruginosa 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 P. aeruginosa 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.