FIG. 6.

Expression of IL-6 mRNA by human MoDM triggered by SP-D-coated noncapsulated K. pneumoniae. Noncapsulated K. pneumoniae strains (10⁸ CFU/ml) were incubated with human macrophages with and without precoating with human SP-D (10 μg/ml). Cytokine mRNA expression was analyzed by RT-PCR. The results are expressed ratios of the optical density (OD) of cytokine to the optical density of β-actin (averages and standard errors of three experiments). Statistical differences (as determined by Student's two-tailed t test) were found for IL-6 mRNA production by MoDM exposed to the K50/n O3-bearing K. pneumoniae strain with and without SP-D (P = 0.035) and for IL-6 mRNA production by MoDM exposed to the K55/n O3-bearing K. pneumoniae strain with and without SP-D (P = 0.00038).