First Author | de Hooge AS | Year | 2000 |
Journal | Am J Pathol | Volume | 157 |
Issue | 6 | Pages | 2081-91 |
PubMed ID | 11106580 | Mgi Jnum | J:66135 |
Mgi Id | MGI:1928019 | Doi | 10.1016/S0002-9440(10)64846-8 |
Citation | de Hooge AS, et al. (2000) Involvement of IL-6, apart from its role in immunity, in mediating a chronic response during experimental arthritis. Am J Pathol 157(6):2081-91 |
abstractText | Interleukin-6 (IL-6) is highly produced during arthritis but its exact function is still unknown. In this study we examined if IL-6, apart from its role in immunity, was involved in the local inflammatory response in experimental arthritis. IL-6 deficient (IL-6(-/-)) and wild-type mice were first compared in the antigen-induced arthritis model. IL-6 deficiency resulted in a mild, transient inflammation whereas wild-type mice developed a chronic, destructive synovitis. Wild-type mice immunized with one-tenth of the normal antigen dose still developed chronic arthritis despite low antibody levels, excluding reduced humoral immunity in IL-6(-/-) mice as a crucial phenomenon. In addition, passive immune-complex-induced arthritis did not differ between wild-type and IL-6(-/-) mice. Another option is reduced levels of Th1 cells in IL-6(-/-) mice. However, transfer of antigen-specific wild-type lymph node cells to IL-6(-/-) mice enhanced acute joint inflammation and increased cartilage damage but still could not sustain chronic inflammation, suggesting involvement of nonimmune elements of IL-6 activity in chronicity. In line with this, nonimmunologically mediated zymosan-induced arthritis developed similarly in the first week, but only wild-type mice developed chronic synovitis. These results indicate an important role for IL-6 in propagation of joint inflammation, potentially independent of its role in immunity. |