Fig. 1.

Francisella-mediated antagonism of TLR4-mediated signaling correlates with strain virulence and not bacterial replication levels. a Heatmap represents expression profiles of sequences that are regulated (at least 2-fold change in median expression level, p value < 0.01) in lung tissue in response to aerosolized E. coli LPS. Each panel reflects separate exposure studies with BALB/c mice infected with either F novicida (FN), F. tularensis subsp, holartica (LVS) or F. tularensis subsp. tularensis (SchuS4). Each column represents gene expression data comparing RNA from lung tissue from an individual infected animal to pooled RNA isolated from mock animals (n = 6). Sequences shown in red represent increased expression. Sequences shown in green represent decreased expression and sequences shown in black indicate no change in expression in treated relative to control animals. b Replication levels of Francisella strains in lungs of Balb/c mice approximately 20.5 h post-infection as measured by qPCR of 16S rRNA. Data represents mean and standard deviation of three individual animals