ADHESION MOLECULE MONOCLONAL-ANTIBODIES INHIBIT EXPERIMENTAL AUTOIMMUNE-THYROIDITIS

To examine the role played by adhesion molecules in thyroid autoimmuni ty, we have assessed the effect of administering monoclonal antibodies (mAb) against intercellular adhesion molecule-1 (ICAM-1) and lymphocy te function-associated antigen-1 (LFA-1) in experimental autoimmune th yroiditis, induced by immunizing rats with thyroglobulin in complete F reund's adjuvant. The antibody against LFA-1, but not against ICAM-1, reduced thyroglobulin antibody production (P < 0.01) and both antibodi es caused a significant reduction (P < 0.002) in the severity of the t hyroidal lymphocytic infiltration. In vitro, both mAb impaired the pro liferative response of splenic and lymph node T cells to thyroglobulin , but only the antibody against LFA-1 reduced thyroid cell killing ass essed using splenic lymphocytes as effectors. Monoclonal antibodies ag ainst both these adhesion molecules appear to inhibit cell-mediated au toimmunity in vivo, but only the LFA-1 mAb reduced the autoantibody re sponse.