Figure 6. Inhibition of MASP-2 increases the severity of S. pneumoniae infection.

WT C57/BL6 mice were dosed i.p. with 1.0 mg/kg body weight of anti-MASP-2 mAb AbD04211 (open triangles) or an isotype control mAb (crosses) 12 h before being infected with 1×10⁶ cfu S. pneumoniae D39. MASP-2 inhibition significantly worsened survival (A) and there was a corresponding increase in viable S. pneumoniae counted in peripheral blood after infection (B). Treatment with 20 mg/kg body weight ceftriaxone 12 hr before infection and every 12 hr thereafter afforded complete protection from S. pneumoniae in animals injected with AbD04211 (filled triangles in A). Results in B are means (±SEM) of twelve animals from which blood was taken at each time point. *p<0.05 (ANOVA).