FIGURE 2.

Cell-to-cell contact is not necessary for inhibition of TNF-α production by macrophages. A, TNF-α production by J774 macrophages (mTNF-α) pretreated with the phagocytosis inhibitor cytochalasin D for 1 h, followed by co-culture with actinomycin D (ActD)-treated Jurkat T cells and LPS stimulation as described in the legend to Fig. 1. B, TNF-α production by J774 macrophages co-incubated directly with actinomycin D-treated Jurkat T cells (as in Fig. 1) or separated by filters with 0.4-μm pores (Transwell) and treated with LPS. Data are presented as means ± S.E. from three independent experiments. *, statistically significant differences between the indicated values (p < 0.05; ANOVA). n.s., not statistically significantly different.