Role of CD4+ cells in the effect of prior colonisation on subsequent pneumonia.

<p>Cytokine levels (A) and bacterial CFU (B) recovered from colonised or control CBA/Ca mice 18 h following pneumonia challenge in the absence of CD4+ cells. Mice were depleted of CD4+ cells using GK1.5 prior to challenge. (A) Cytokine levels in BALF of colonised mice (black bars) or control mice (white bars) measured by Luminex or ELISA. Group mean + SEM are displayed. (B) Bacterial cfu in BALF, lung and blood of colonised or control CBA/Ca. Each symbol represents results for an individual mouse and bars the median for each group. The dotted line is the limit of detection. Significance of the difference in bacterial numbers recovered from lungs of colonised and control mice was assessed by Mann-Whitney U-test. Significance of differences in presence or absence of bacteraemia was assessed by Fisher exact test. Data are pooled from two experiments with similar results.