The culture was diluted 1:100 into fresh broth and then shaken at 37°C until the late logarithmic growth phase. To produce agar medium, LB broth was solidified by adding 1.5% (wt/vol) agar (Nacalai Tesque, Kyoto, Japan). Specific pathogen-free female C57BL/6 mice were purchased from Japan SLC (Shizuoka, Japan). All experimental mice were 8–10 weeks old. The animals were housed under specific pathogen-free conditions in a small level two animal containment facility and given see more free access to sterile water and certified mouse chow. All experiments were carried out in accordance with the guidelines for the care and use of laboratory animals

of Osaka University of Pharmaceutical Sciences. Acinetobacter baumannii was grown until the late logarithmic growth phase, centrifuged at 3,500 ×g for 10 min, resuspended and diluted appropriately in PBS, and used immediately. Mice were anesthetized and i.n. inoculated with approximately

107 or 108 CFU A. baumannii in 50 μL PBS. The actual PD-332991 inoculum concentrations were determined by plating 10-fold serial dilutions onto LB ager plates. Clinical signs were monitored and scored as follows: 0, no abnormal clinical signs; 1, ruffled fur and moving slowly; 2, ruffled fur, hunched posture, and moving very slowly; 3, hunched posture, moving very slowly, and squeezed eyes; 4, dead. Pulmonary lobes were harvested at the indicated time points and fixed in 10% neutral buffered formalin, which was then replaced by a sucrose solution. The lungs were then embedded in OTC (Tissue-Tec; Miles Inc., Elkhart, IN, USA) and frozen at −80°C. The tissue segments were sectioned (6 μm) on a cryostat and stained with hematoxylin and eosin (H & E). Acinetobacter baumannii-inoculated mice were killed and lungs and spleen were removed. Each tissue was homogenized with PBS in a loose glass homogenizer. Cell suspensions were plated on LB agar plates and cultured at 37°C for

12 hrs. Anti-M-CSFR (AFS98) was a gift from Dr S. I. Nishikawa (RIKEN, Kobe, Japan) (21). Anti-Gr1 (RB6–8C5) and anti-NK1.1 (PK136) were provided by the Cell Resource Center for Biomedical Research Institute of Development, Mirabegron Aging and Cancer Tohoku University. Anti-CD11b (M1/70), CD45 (30-F11), CD3 (145–2C11) and CD49 (DX5) were purchased from BD Pharmingen (San Jose, CA, USA). To deplete neutrophils, NK/NKT cells, and macrophages, mice were injected i.p. with 250 μg anti-mouse monoclonal antibodies, RB6–8C5, PK136, and AFS98 (23–25), respectively, on Days 5, 3, and 1 before and Days 1 and 3 post-inoculation with A. baumannii. Pulmonary lobes were removed, minced in Hanks’ Balanced Salt Solution (HBSS; Invitrogen, Carlsbad, CA, USA) and incubated with 150 U/mL collagenase (Sigma, St Louis, MO, USA) and 0.1 mg/mL DNase I (Wako Pure Chemicals, Osaka, Japan) for 30 min at 37°C. Spleens were homogenized in PBS using a loose glass homogenizer, centrifuged for 5 min, resuspended in PBS, and passed through nylon mesh (70 μm).