FIG. 5.

Expression of IL-1β 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 as the 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-1β mRNA production by MoDM exposed to the K50/n (P = 0.00004) and K55/n (P = 0.000025) O3-bearing K. pneumoniae strains with SP-D and for IL-1β mRNA production by MoDM exposed to the K50/n and K55/n O3-bearing K. pneumoniae strains without SP-D.