Regulation of integrin 6 subunit and CCR1 by IL-12 and IFN- in Th1 cells. Th1 cells were cultured in medium supplemented with IL-2 and stimulated with IL-12 or IFN- as described in Materials and Methods. At different times after stimulation with the cytokines, the cells were harvested, washed, and total RNA extracted. 10 μg of total RNA purified from untreated or cytokine-stimulated Th1 cells were subsequently used for Northern blot analysis. Filters were hybridized with ³²P-labeled probes for integrin 6, CCR1, and GAPDH. One representative experiment of 2 performed is shown. (B) 24 hours after the addition of the cytokines, Th1 and Th2 cells were harvested, washed, and loaded with Fluo-3AM. Untreated cells (dotted lines), IFN-–treated cells (dashed lines), or IL-12–treated cells (solid lines) were analyzed by FACS before and after addition of MIP-1. Time of addition of MIP-1 is indicated by the arrow. The response is expressed as fold increase of mean fluorescence intensity at time 0 for emissions at 525 nm. One representative experiment of 5 performed is shown.