Figure 6.

Suppression by polymyxin B of LPS-induced reactivation of CIA. Mice were immunized with CII on day 0 followed by a booster injection on day 21 as described in Methods. On day 50, 100 μl of saline alone or 100 μl of saline containing 50 μg of polymyxin B sulphate (PMB) was mixed with saline, 5 μg of LPS, and 2 μg of lipid A and then i.p. injected on day 50. The severity of arthritis was determined on day 55. Bars show the mean±s.e.mean of ten mice. ^*P<0.05 versus saline- and LPS-treatment; ^**P<0.05 versus saline- and lipid A-treatment, Mann-Whitney U-test. Data are representative of two experiments.