Figure 1

Arthritis induction by high mobility group box chromosomal protein 1 in TNFα^-/- mice and controls. Arthritis incidence (%) and arthritis severity scores (mean ± standard error of the mean) are shown in TNFα^-/- mice (squares) and in control mice (circles) (n = 18 to 19 per group) following a single intraarticular injection of 5 μg high mobility group box chromosomal protein 1 (HMGB1). Empty squares/circles, individual mice (n = five to six per group) receiving recombinant HMGB1 containing a minimal amount of lipopolysaccharide (see Materials and methods); filled squares/circles, mice (n = 12 to 14 per group) receiving lipopolysaccharide-free HMGB1.