FIG. 2.

MTT analysis of the response of cells to various mutations and deletions of the intracellular domain of IL-7R. Transfected D1 cells were maintained in mIL-7, washed, and cultured for 48 h with 50 ng of mIL-7/ml or 50 ng of hIL-4/ml. Results are from one representative experiment of three performed. Chimeric constructs imparted a response to hIL-4. Deletion of Box1 or mutation of Y449 in the intracellular domain of IL-7R severely impaired the response. OD(570-620), absorbance at 570 nm minus background absorbance at 620 nm.