Figure 1 From: Tumor necrosis factor alpha and adalimumab differentially regulate CD36 expression in human monocytes Regulation of CD36 membrane expression by tumor necrosis factor (TNF)α and adalimumab (Ada). (a) TNFα reduces the membrane expression of CD36: time course. Human monocytes were incubated with macrophage-serum-free medium (M-SFM) alone (control), or with M-SFM containing TNFα (10 ng/ml) for 6 to 12 and 24 h. Membrane expression of CD36 was quantified using flow cytometry. Data represent the geometric mean ± standard error (SE) of the fluorescence measured in three experiments in duplicate. *Significantly different from control (p < 0.05). (b) TNFα reduces membrane expression of CD36: dose effect. Human monocytes were incubated for 24 h with M-SFM alone (control), or with M-SFM containing TNFα at increasing concentrations (0.1, 1, or 10 ng/ml) for 24 h. Membrane expression of CD36 was quantified using flow cytometry. Data represent the geometric mean ± SE of the fluorescence measured in four experiments. *Significantly different from control (p < 0.05). (c) The reduction of membrane expression of CD36 induced by TNFα is inhibited by adalimumab independently of TNFα. Human monocytes were incubated with M-SFM alone (control), or with M-SFM containing either TNFα alone (10 ng/ml), TNFα combined with adalimumab (Ada; 1 μg/ml) or adalimumab alone for 24 h. Membrane expression of CD36 was quantified using flow cytometry. Data represent the geometric mean ± SE of the fluorescence measured in four experiments. *Significantly different from control (p < 0.05). (d) The increase in CD36 membrane expression induced by adalimumab is antibody-specific. Human monocytes were incubated with M-SFM alone (control), or with M-SFM containing either adalimumab (Ada; 1 μg/ml), or rituximab (Ritux; 1 μg/ml), a human anti-CD20 IgG1 monoclonal antibody, as a control antibody for 24 h. Membrane expression of CD36 was quantified using flow cytometry. Data represent the geometric mean ± SE of the fluorescence measured in four experiments in duplicate. *Significantly different from control (p < 0.05). (e) Adalimumab increases membrane expression of CD36: time course. Human monocytes were incubated with M-SFM alone (control), or with M-SFM containing adalimumab (Ada; 1 μg/ml) for 6 to 12 and 24 h. Membrane expression of CD36 was quantified using flow cytometry. Data represent the geometric mean ± SE of the fluorescence measured in three experiments in duplicate. *Significantly different from control (p < 0.05).Back to article page