Experimental synovitis induced by collagen-specific T cell lines.

Type II collagen (CII) and ovalbumin (OV) reactive T cell lines were developed from the lymph node cells of Louvain rats previously immunized with the respective antigen. Histologic sections of rat knees injected intraarticularly (ia) with 10(6) cells from line CII (VA) or CII (VII) were graded blindly. Significant synovitis (P less than 0.000001 and 0.004, respectively) was evident compared to OV line recipients. Pannus developed within 48 hr, persisted for at least 4 to 6 weeks, was inducible with fewer than 10(3) CII cells, and required viable lymphocytes. The process was independent of anticollagen antibodies and was associated with the lines' capacity to elaborate a previously described 65-kDa CII-binding arthritogenic lymphokine. Line CII (VIII), which could not elicit a synovitis, did not produce detectable quantities of this factor. A line- and antigen-specific synovitis, comparable to the ia injection protocol, was also induced by intravenous administration of 2 x 10(7) CII (VA) cells and ia challenge with soluble collagen. These studies demonstrate that CII lines bearing the T helper phenotype can evoke a sustained synovitis and suggest that this experimental process is associated with the release of an arthritogenic lymphokine and not dependent on the formation of antibodies to CII.