Figure 2

The lone cytoplasmic tyrosine residue of human TSLPR is not required for TSLP-dependent cell proliferation. (A) A schematic illustration of the human TSLP receptor complex composed of the human IL-7Rα and the human TSLPR. Y denotes the cytoplasmic tyrosine residues. (B) Exponentially growing Ba/F3 cells were starved and then treated with human TSLP (100 ng/ml). The data are represented as fold changes with the number of cells seeded on day 0 (for TSLP stimulation) representing the baseline. The mean of experiments done in triplicate for each time point and each cell line is shown. Error bars indicate S.E.M. (C) Surface expression of the wild type human TSLPR and IL-7Rα in the cell lines used in (B). Exponentially growing infected Ba/F3 cells were analyzed by flow cytometry for cell surface expression of human TSLPR and IL-7Rα. (D) TSLP-induced proliferation of Ba/F3 cells co-expressing the indicated were examined as described in (B). Statistical significance of the proliferative responses in the different cells at the same time point was evaluated using unpaired Student's t-test (* indicates a significant difference with p-value < 0.01). (E). Exponentially growing Ba/F3 cells were starved and then stimulated with the indicated concentration of human TSLP for 3 days. Cell numbers were counted after 3 days. The data are represented as fold changes with the number of cells seeded on day 0 (for TSLP stimulation) representing the baseline. Statistical significance of the proliferative responses in the different cells in response to the same dose of TSLP was evaluated using unpaired Student's t-test (* indicates a significant difference with p-value < 0.01). (The growth of cells was examined in 3 independent sets of experiments and found to be similar. The results from one representative experiment are shown).