Immunisation with hGPI
induces severe polyarthritis. DBA/1 mice were immunised with 25 μg of hGPI325–339, hGPI539–558 or hGPI544–558, or 10 μg each of hGPI325–339 plus hGPI544–558, and 200 ng of pertussis toxin was injected intraperitoneally on days 0 and 2 after immunisation. (a) The mean arthritis score (± standard error of the mean (SEM)) of five mice in one representative experiment of two independent experiments. (b) Severe swelling of the wrist (upper panels) and ankle joints (middle panels) in mice immunised with 25 μg of hGPI325–339 compared with naïve mice (arrowheads). Histological analysis of haematoxylin & eosin-stained sections of ankle joints taken from naïve mice and mice on day 14 after hGPI325–339 immunization (lower panels) showed severe synovitis with massive infiltration of cells and hyperplasia of synovial tissue (arrowheads).