Proinflammatory mediator-induced reversal of CD4+,CD25+ regulatory T cell-mediated suppression in rheumatoid arthritis.

Objective: We previously demonstrated that CD4+,CD25+ regulatory T (Treg) cells are present in increased numbers in the synovial fluid (SF) of rheumatoid arthritis (RA) patients and display enhanced suppressive activity as compared with their peripheral blood (PB) counterparts. Despite the presence of these immunoregulatory cells in RA, chronic inflammation persists. The purpose of the present study was to investigate whether particular proinflammatory mediators that are associated with RA could abrogate CD4+,CD25+ Treg-mediated suppression.

Modulation of monocyte/macrophage function by human CD4+CD25+ regulatory T cells.

The suppressive effects of CD4+CD25+ regulatory T cells (Tregs) on T cells have been well documented. Here we investigated whether human CD4+CD25+ Tregs can inhibit the proinflammatory properties of monocytes/macrophages. Monocytes and T cells were isolated from peripheral blood of healthy volunteers by magnetic cell separation and cocultured for 40 h.

CD4(+)CD25(+) regulatory T cells in rheumatoid arthritis: differences in the presence, phenotype, and function between peripheral blood and synovial fluid.

Objective: In mice, CD4(+)CD25(+) regulatory T cells play a pivotal role in preventing autoimmunity. Regulatory T cells are also present and functional in healthy humans. We investigated the presence, phenotype, and function of CD4(+)CD25(+) regulatory T cells in peripheral blood (PB) and synovial fluid (SF) from patients with rheumatoid arthritis (RA).