Ia antigen mediated specific antigen presenting function of articular chondrocytes.

The ability of articular chondrocytes to function as antigen presenting cells (APC) was examined. Rabbits were immunized with ovalbumin (OVA) in complete Freund’s adjuvant. Four weeks later, axillary lymph nodes were obtained. Spleen cells were used as positive controls. Chondrocytes were separated by collagenase, DNAse, and hyaluronidase digestion of dissected cartillage from femurs and tibias. Nylon wool purified T lymphocytes were cocultured with OVA pulsed and mitomycin-C treated chondrocytes and spleen cells. The proliferative response of autologus T lymphocytes was measured by H-thymidine uptake. Chondrocytes as well as spleen cells showed antigen presenting acitivty. This activity was inhibited by mouse monolonal anti-rabbit la antibody. These results indicate that articular chondrocytes function as antigen presenting cells in common with spleen cells, la antigen is a regulatory element in conjunction with soluble antigen for this process.