Figure 6. MPLA protects against E. coli-induced severe sepsis.

(A and B) WT mice injected with MPLA show survival of a lethal dose of E. coli RS218D. WT mice (CF-1, 15/group, and C57Bl6, 12/group) were injected with E. coli (2.6–3.4×10⁶ cfu/gbw, i.p.), with or without prior injection of MPLA (36 ng/gbw, i.p., 2 h before E. coli). Survival was monitored over 6 days. (C–F) Effects of MPLA on PMN recruitment and bacterial clearance in WT mice injected with E. coli. Mice (C57Bl6, eight to 10/group) were injected i.p. with E. coli RS218D (3.4×10⁶ cfu/gbw), with or without prior injection of MPLA (2 h before E. coli) and PMN recruitment (C and D), and bacterial clearance in the PC (E) and blood (F) was determined 3 h after bacterial injection, as described in Fig. 1. (G) MPLA-induced protection can be reversed by treatment with anti-CXCR2. WT mice [C57Bl6 mice (10/group)] were injected with MPLA (36 ng/gbw) and anti-CXCR2 antibodies (100 μg/mouse) in a single injection; 2.5 h later, mice were injected with E. coli RS218D (3.1×10⁶ cfu/gbw). Controls (10/group) were injected with E. coli RS218D alone or with MPLA and an isotype control antibody, followed 2.5 h later by E. coli RS218D. Survival was monitored over 6 days.