Figure 1.

Activation by TNF-α production by wild type and different knockout mouse macrophages. A, Stimulation with Sh. flexneri LPS at 100 ng/ml (solid bars) or synthetic BLP at 20 ng/ml (open bars), showing the dependence on TLR4 and TLR2 respectively and the requirement for MyD88 for both, compared with baseline production in medium alone (hatched bars). B, Effect of increasing concentrations of the different human CRP preparations showing complete absence of activity in the natural material (open bars), compared to marked dose dependent stimulation by the recombinant product that required TLR4, consistent with LPS activity. Similar results were obtained regardless of whether or not the recombinant CRP material was dialyzed before testing.