Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0003864 (arthritis)
 69,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this study the roles of different T-cell subsets, and produced cytokines, were investigated in an animal model for acute exacerbations. Flare-up reactions are inducible in the chronic phase of a smouldering antigen-induced inflammation by injection of a small amount of an antigen into a hyper-reactive knee joint. In vivo treatment with anti-CD4 monoclonal antibodies (mAb) almost totally blocked the flare reaction, whereas anti-CD8 treatment did not exert any effect. The role of T-helper 1 (Th1) cells in delayed-type hypersensitivity-resembling diseases is generally entitled proinflammatory, whereas Th2 cells act in an anti-inflammatory manner. To investigate the role of these T-cell subsets in flare-up reactions, anti-interleukin-2 (IL-2) and anti-IL-4 mAb treatments were performed. Anti-IL-2 treatment partly blocked the flare reaction, and anti-IL-4 treatment, although the result was unexpected, blocked the flare more efficiently. Furthermore, when human recombinant IL-2 (hrIL-2) and murine recombinant IL-4 (mrIL-4) were co-injected with the antigen to test their ability respectively to potentiate or down-regulate the flare reaction, both cytokines demonstrated additional pro-inflammatory effects, although hrIL-2 was more potent than mrIL-4. The mere effect of hrIL-2 and mrIL-4 was studied by direct injection into a hyperreactive joint. No flare-up reaction or cell-influx could be induced, suggesting that other mediators are needed to exert pro-inflammatory effects of IL-2 or IL-4. We conclude that not only Th1 cells, but also Th2 lymphocytes (at least regarding IL-4 production) may play a pro-inflammatory role in flare-up reactions of chronic arthritis. Considering therapeutic application of Th2 cell-derived cytokines, one should be aware of the possible pro-inflammatory potential of IL-4.
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PMID:Role of IL-2 and IL-4 in exacerbations of murine antigen-induced arthritis. 783 64

Interleukin-2 is an immunotherapeutic agent for the treatment of metastatic tumors. Administration of recombinant human IL-2 (rhIL-2) in vivo activates lymphocytes and cell-mediated immune responses. In mice, we have recently observed a dramatic increase of serum IFN-gamma levels in response to in vivo administration of rhIL-2, which was necessary for the observed protective effects of IL-2 against the development of collagen-induced arthritis. To explore further the basis of this phenomenon, the kinetics and source of IFN-gamma in response to IL-2 was investigated. Highest serum levels of IFN-gamma were observed within 3 h of IL-2 administration, with levels decreasing over time. Anti-IL-2 receptor beta antibody blocked this IFN-gamma induction. Multiple doses of rhIL-2 resulted in corresponding increases in circulating IFN-gamma. IFN-gamma induction was dose-dependent between doses of 240 to 30,000 U of rhIL-2. Analysis of the cellular source of IFN-gamma secretion using NK- and T cell-deficient mice demonstrated that NK cells are the likely source of IFN-gamma. Furthermore, IFN-gamma secretion in response to IL-2 administration was not affected by the absence of IL-12, the pivotal cytokine for determination of Th1 responses. These results suggest that effects of IL-2 on immune responses in vivo may be mediated by IFN-gamma.
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PMID:NK cells secrete high levels of IFN-gamma in response to in vivo administration of IL-2. 1174 53