TABLE 2.

Blockade of T-cell-mediated macrophage NO production by anti-LFA-1 MAb^a

Treatment	NO2 (μM)
	Wild type	TNFRp55−/−
Anti-CD3	49 ± 2	33 ± 3
Anti-CD3 plus:
Anti-LFA-1	<4	<4
Anti-ICAM-1	53 ± 1	35 ± 3
Anti-ICAM-2	51 ± 2	32 ± 3
Anti-ICAM-1 + anti-ICAM-2	47 ± 2	27 ± 1
Rat IgG	50 ± 2	29 ± 2

^aBone marrow-derived macrophages were incubated with T cells at a T cell/macrophage ratio of 2:1 and treated with anti-CD3 (5 μg/ml) for 72 h. Some cultures were also treated with MAbs to LFA-1 or with ICAM-1 and/or ICAM-2 (10 μg/ml, final concentration). The data represent the mean NO levels of duplicate cultures ± SE. Similar results were obtained in three additional experiments.