Research article

Cartilage oligomeric matrix protein deficiency promotes early onset and the chronic development of collagen-induced arthritis

Hui Geng^1,2 , Stefan Carlsen¹ , Kutty Selva Nandakumar¹ , Rikard Holmdahl¹ , Anders Aspberg^1,3 , Åke Oldberg¹ and Ragnar Mattsson¹

¹  Department of Experimental Medical Sciences, BMC, Lund University, Sölvegatan 19, SE-22184 Lund, Sweden

²  Current address: Department of Biochemistry and Molecular Biology, College of Life Science, Huazhong Normal University, No. 100 Luoyuroad, Wuhan 430079, PR China

³  Department of Biology, University of Copenhagen, Biocenter, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark

author email corresponding author email

Arthritis Research & Therapy 2008, 10:R134doi:10.1186/ar2551

Published:	14 November 2008

Abstract

Introduction

Cartilage oligomeric matrix protein (COMP) is a homopentameric protein in cartilage. The development of arthritis, like collagen-induced arthritis (CIA), involves cartilage as a target tissue. We have investigated the development of CIA in COMP-deficient mice.

Methods

COMP-deficient mice in the 129/Sv background were backcrossed for 10 generations against B10.Q mice, which are susceptible to chronic CIA. COMP-deficient and wild-type mice were tested for onset, incidence, and severity of arthritis in both the collagen and collagen antibody-induced arthritis models. Serum anti-collagen II and anti-COMP antibodies as well as serum COMP levels in arthritic and wild-type mice were measured by enzyme-linked immunosorbent assay.

Results

COMP-deficient mice showed a significant early onset and increase in the severity of CIA in the chronic phase, whereas collagen II-antibody titers were similar in COMP-deficient and wild-type controls. COMP antibodies were not found in wild-type mice. Finally, COMP-deficient and wild-type mice responded similarly to collagen antibody-induced arthritis, indicating no difference in how collagen II antibodies interact with COMP-deficient cartilage during the initial stages of arthritis.

Conclusions

COMP deficiency enhances the early onset and development of chronic arthritis but does not affect collagen II autoimmunity. These findings accentuate the importance of COMP in cartilage stability.