Interactions between anticollagen antibodies and chondrocytes

To investigate the interactions between anticollagen antibodies and living chondrocytes.

Mouse monoclonal anti-type II collagen (anti-CII) antibodies, rabbit anti-human CII, and rat anti-CII, anti-CIV, anti-CV, anti-CVI, and anti-CIX were studied in vitro to determine their ability to bind to the plasma membrane of living bovine chondrocytes.

Mouse monoclonal anti-CII, rabbit anti-CII, and rat anti-CII, anti-CV, and anti-CIX were shown to bind in vitro to the plasma membrane of bovine chondrocytes. Antibody binding was not observed with anti-CIV, or with chondrocytes previously incubated with bacterial collagenase. A significant increase in chondrocyte caseinase and collagenase secretion was observed following sequential incubation with the monoclonal antibodies and a source of activating cytokines.

These results suggest that collagen autoantibodies may exert some of their pathogenic effects on cartilage through interactions with resident chondrocytes, leading to modulation of the rate of secretion of cartilage matrix-degrading enzymes.