Figure 2

Decreased T cell induced production of TNF-α in monocytes from RA patients. (a) T cell-induced tumour necrosis factor (TNF)-α secretion by monocytes from patients with rheumatoid arthritis (RA) is decreased in comparison with those from healthy controls. Peripheral-blood T cells (10⁶/ml) were cultured for 48 hours in the presence or absence of immobilized anti-CD3 (3.3 μg/ml) and soluble anti-CD28 (0.8 μg/ml) antibodies. Stimulated (sTc) and resting (rTc) T cells were fixed and incubated with freshly isolated monocytes (1.5 × 10⁶/ml) at a ratio of 7:1. After 24 hours, the concentration of TNF-α was measured in the supernatant. Lipopolysaccharide (LPS; 100 ng/dl) was used as a positive control. Data are means ± SEM of values from 20 patients with RA and 20 age-matched controls. (b) Macrophages separated from the synovial membrane of patients with RA produce large amounts of TNF-α after contact with preactivated T cells. Stimulated (sTc) and resting (rTc) T cells were fixed and incubated with freshly isolated synovial macrophages from patients with RA (1.5 × 10⁶/ml) at a ratio of 7:1. After 24 hours, the concentration of TNF-α was measured in the supernatant. LPS (100 ng/ml) was used as a positive control. Data are means ± SEM of values from six independent experiments. Level of significance: not significant. (c) Decrease in T cell-induced TNF-α secretion by monocytes from patients with RA is independent of previous and current treatments. The graph depicts the T cell-induced TNF-α production by monocytes of patients with RA either receiving methotrexate (MTX; n = 5) or not receiving immunosuppressive treatment (untreated; n = 6). For comparison, results for six age-matched controls are given (P < 0.05, significant difference compared with untreated patients).