Upregulation of integrin 6/β1 and CCR1 by IL-12 promotes the migration of Th1 cells. IL-12–treated or untreated fluorescent-labeled Th1 cells were added to triplicate transwell filters that had been coated with fibronectin or laminin. Indicated concentration of chemokines SDF-1 and MIP-1 was added to the lower compartment of the transwell. The percentage of input cells that migrated to the bottom of the transwell after 3 hours of incubation was determined by flow cytometric analysis as described for Fig 5. Data are expressed as the ratio of migrated IL-12–treated versus untreated Th1 cells. The dashed horizontal line indicates the ratio equal to 1, which would result from an equivalent migration of IL-12–treated versus untreated Th1 cells. The experiments shown are representative of 5 performed.