Volume 46, Issue 5 pp. 1379-1389
Original Article

Local interleukin-12 gene transfer promotes conversion of an acute arthritis to a chronic destructive arthritis

Leo A. B. Joosten

Corresponding Author

Leo A. B. Joosten

University Medical Center Nijmegen, Nijmegen, The Netherlands

Rheumatology Research Laboratory, University Medical Center Nijmegen, PO Box 9101, Nijmegen 6500 HB, The NetherlandsSearch for more papers by this author
Marleen Heuvelmans-Jacobs

Marleen Heuvelmans-Jacobs

University Medical Center Nijmegen, Nijmegen, The Netherlands

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Erik Lubberts

Erik Lubberts

University Medical Center Nijmegen, Nijmegen, The Netherlands

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Fons A. J. Van De Loo

Fons A. J. Van De Loo

University Medical Center Nijmegen, Nijmegen, The Netherlands

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Andrew C. Bakker

Andrew C. Bakker

University Medical Center Nijmegen, Nijmegen, The Netherlands

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Monique M. A. Helsen

Monique M. A. Helsen

University Medical Center Nijmegen, Nijmegen, The Netherlands

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Carl D. Richards

Carl D. Richards

McMaster University, Hamilton, Ontario, Canada

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Wim B. Van Den Berg

Wim B. Van Den Berg

University Medical Center Nijmegen, Nijmegen, The Netherlands

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First published: 08 May 2002
Citations: 17

Abstract

Objective

To determine whether local overexpression of interleukin-12 (IL-12), a pleiotropic cytokine that promotes the development of naive T cells into Th1 cells, could aggravate murine streptococcal cell wall (SCW)-induced arthritis, a model of acute arthritis.

Methods

C57BL/6 mice were injected intraarticularly with saline or with 107 plaque-forming units of control vector (Ad5del70-3) or IL-12 vector (AdmIL-12.1) into the right knee joint 1 day before intraarticular injection of 25 μg of SCW fragments. The development of joint swelling, changes in chondrocyte proteoglycan (PG) synthesis, and joint destruction were examined thereafter.

Results

In normal joints, high levels of IL-12 (20 ng/ml on day 1) could be detected after application of the AdmIL-12.1 vector. After 14 days, expression of IL-12 was still found locally, but IL-12 alone did not induce protracted inflammation. Local expression of IL-12, in combination with SCW, markedly aggravated SCW-induced arthritis, as determined by enhanced joint swelling and prolonged inhibition of chondrocyte PG synthesis. Histologic examination on day 21 showed a chronic inflammatory process, with persistent cartilage PG depletion, cartilage erosion, and VDIPEN neoepitope expression (indicative of metalloproteinase activation). The mixture of IL-12 with SCW fragments did not lead to a chronic destructive process in mice deficient for recombination-activating gene 2, indicating the involvement of lymphocytes. In addition, systemic flare of smoldering SCW arthritis, produced by intravenous injection of SCW fragments, was only seen in the AdmIL-12/SCW group.

Conclusion

These results indicate that local overexpression of IL-12 promotes conversion of an acute arthritis to a chronic destructive immune-mediated process, which is more susceptible to flares.

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