Microarray analysis of CD4+T cells in murine arthritis

Although activated CD4+ T cell-driven overproduction of cytokines, especially TNF and IL1, is generally regarded as the major factor in the development of rheumatoid arthritis (RA), little is known about the precise role of CD4+ T cells in the initiation and progression of this disease. In this study, this issue was addressed using a time-course microarray analysis in a mouse model of RA, Il1rn deficient mice.No obvious cytokine gene expression changes reflecting T cell activation was observed in CD4+ T cells in the Il1rn deficient mice during the course of spontaneous arthritis. On the contrast, majority of dysregulated genes were those predominantly expressed in myeloid lineage cells, suggesting T cell reprogramming involvement in arthritis development. Distinct gene expression patterns were identified for different stages of disease, including downregulated expression of immunoglobulin heavy chain constant region genes and increased expression of inflammatory genes in the early phase, and downregulation of MHC class II genes in the late phase. The common changes occurred in both early and late phases included upregulation of Arl2bp and Mfap1, which are involved in the regulation of cytoskeletal dynamics. Keywords: Time course Two KO mice and three WT mice for each time point (1 month and 4 month) were used for this study.