Pam2-ODN protects mice against bacterial pneumonia despite cytotoxic chemotherapy. (A) Experimental schema. (B) Mouse circulating neutrophil counts after 3 days of treatment with idarubicin 33 mg/kg and cytarabine 1 mg/kg (low), idarubicin 50 mg/kg and cytarabine 1 mg/kg (high), or sham treatment with PBS (none). (C) Mouse survival of P. aeruginosa challenge (10 mL of 2 × 10¹⁰ CFU/mL bacterial suspension nebulized over 60 minutes) following the indicated treatments. (D) Lung bacterial burden of mice treated with high-dose idarubicin and cytarabine immediately after infection. (E) Mouse survival of S. pneumoniae challenge (10 mL of 2 × 10¹⁰ CFU/mL) following high-dose idarubicin and cytarabine treatment and inhaled treatment with Pam2-ODN or sham (PBS). (F) Lung bacterial burden immediately after infection. (G) Mouse survival of P. aeruginosa challenge (10 mL of 2 × 10¹⁰ CFU/mL) following high-dose daunorubicin and cytarabine treatment and inhaled treatment with Pam2-ODN or sham (PBS). (H) Lung bacterial burden immediately after infection. For survival experiments, N = 10 mice per group; for bacterial burden, N = 4 mice per group. *P < .005 vs no chemotherapy; **P < .05 vs mice treated with the same chemotherapy followed by PBS (sham) nebulization.