Figure 5. Defective K. pneumoniae-induced activation of NF-κB, MAPKs, and expression of ICAM-1 in the lungs of CXCL1^-/- mice is corrected by LTB₄.

Activation of NF-κB and MAPKs and expression of ICAM-1 and VCAM-1 (A) in K. pneumoniae-infected and LTB₄ administered homogenized whole lungs at 48 h post-infection. WT and CXCL1^-/- mice were infected with 10³ CFU of K. pneumoniae cells via the i.t. route and treated with LTB₄ (100 ng/mouse) or vehicle administration 1 h later. Data are presented as a representative of three independent blots/experiments. Densitometric analysis (B) of activation of NF-κB and MAPKs and expression of ICAM-1 and VCAM-1 in the lung homogenates after LTB₄ or vehicle treatment. Data represent the means ± SEM of arbitrary densitometric units for each band from three independent blots/experiments. (* indicates p<0.05 as compared to BSA treated C57Bl6 or CXCL1^-/- mice). Expression levels of p67^phox, p47^phox, and iNOS (C) in homogenized lungs of K. pneumoniae-infected and i.t.-treated with vehicle or LTB₄ (100 ng) 1 h post-infection. This blot is representative of three independent blots. Densitometric analysis of iNOS, p67^phox, and p47^phox levels in lung (D) homogenates from three independent experiments (p<0.05). (* indicates p< 0.05 compared with C57Bl6 or CXCL1^-/- vehicle (BSA) administered mice (n=5-6/group). For experiments A-D, a total of 6-9 mice/group was used.