Figure 1.

Increased GBS in lung homogenates from GM^–/– mice. Concentration of GBS was determined by quantitative cultures of lung homogenates. Colony counts were significantly greater 6, 24, and 48 h after administration of 10⁴ CFU GBS in GM^–/– (solid bars) compared with GM^+/+ (hatched bars) mice. Six hours after GBS infection, clearance of GBS from the lung was enhanced in SP-C-GM (open bars) mice compared with GM^+/+ mice. Data were not obtained for SP-C-GM mice at 48 h. Data are mean ± SEM with n = 10 mice per group. *P < 0.05 compared with GM^+/+ mice. GBS, group B streptococcus; GM^–/–, GM-CSF gene-targeted mice; SP-C-GM, human surfactant protein C (SP-C) gene promoter expressing GM-CSF.