FIGURE 5.
Protection of bacteria from AMP-mediated toxicity. A and B, repression of antimicrobial activity of AMP by the addition of exogenous recombinant Lpp or anti-Lpp antibody is shown. The viability of K. pneumoniae or P. aeruginosa (5–10 × 104 cfu) treated with 0.1 μm SMAP-29, 0.2 μm CAP-18, 0.2 μm LL-37, 0.1 μm Protegrin-1, or 0.1 μm Polymyxin B was measured in the presence of increasing amounts of recombinant Lpp (A) or anti-Lpp antibody (B) as indicated. C, protection of various microbes from the action of SMAP-29 by the pretreatment with anti-Lpp antibody is shown. D, repression of AMP-induced increase of membrane permeability by anti-Lpp antibody is shown. Bacteria (107 cfu) containing 1 μm SYTOX® Green were incubated with or without anti-Lpp antibody in a dark 96-well plate for 15 min before the treatment of 5 μm SMAP-29, 5 μm CAP-18, and 40 μm Polymyxin B and assayed for fluorescence as described in Fig. 1C.