Inhibitory effects of the anti-rat T-cell receptor (TCR) monoclonal antibody (MAb) R73 on various experimental autoimmune diseases.

The anti-rat alpha/beta-TCR, MAb-R73 has been investigated as to its disease modifying activity on adjuvant arthritis (AA), on experimental allergic encephalomyelitis (EAE) and on a local graft versus host (GvH) reaction (popliteal lymph nodes = PLN) in Lewis or Brown-Norway rats. R73 was able to prevent the onset of the AA and even if therapy started after the establishment of AA the MAb was still able to reduce the degree of chronic inflammation and arrest its progress. Intravenous MAb-R73 application also reduced the signs of EAE and prevented mortality. This was even seen when the substance was given after the outbreak of the clinical symptoms or when the F(ab)2 fragment of this MAb was used. Also in the model of local GvH reaction R73 acted therapeutically and lowered the PLN weights.