Detection of collagenase-induced damage of collagen by 9A4, a monoclonal C-terminal neoepitope antibody

To determine whether the collagen network is compromised by collagenase dur ing acute inflammation, a monoclonal antibody (9A4) was developed with spec ificity for the C-terminal neoepitope sequence generated by collagenase-cle avage of type II collagen (Gly-Pro-Pro-Gly-Pro-Gln-Gly-COOH). 9A4-was shown to detect the collagen collagenase-cleavage neoepitope with a K = 1.7 X 10 (-7) M (type II) and K = 2 x 10(-6) M (type I). It does not recognize uncle aved native or denatured collagen. Articular cartilage from control animals is unstained by 9A4. During acute inflammation elicited in hamsters by int ra-articular LPS, positive staining for the 9A4 neoepitope indicated the co llagen was damaged. Wheel running exercise was used to apply stress to cont rol cartilage and cartilage from animals with damaged collagen. After 6 mon ths of running, the cartilage from normal animals was unaffected. By contra st, in the group with damaged collagen, the cartilage was fibrillated in al l animals and in half of those, the cartilage failed and bony eburnation re sulted. (C) 1999 Elsevier Science B.V./International Society of Matrix Biol ogy. All rights reserved.