Table 2.

Antibody-binding sites on LFA-1 on lymphocytes

Stimulation	Binding sites per cell
	AL-57	KIM127	TS2/4
None	200 ± 100	300 ± 100	27,000 ± 3,300
PMA	3,900 ± 1,300*	2,800 ± 700*	34,000 ± 3,800
CXCL-12	2,200 ± 800*	3,300 ± 500*	34,000 ± 3,800

Human T lymphocytes were stimulated with PMA (100 nM) or CXCL-12 (SDF-1, 100 ng/ml) for 20 min at 37°C in the continued presence of antibody. Binding sites were determined with FITC anti-κ light chain and AL-57 Fab or FITC-KIM127 and FITC-TS2/4 IgG, and standardization was performed with beads containing known numbers of mouse IgG-binding sites as described in Methods. Data are the average of at least three independent experiments ± SEM.

*, P < 0.05 vs. no stimulation.