Figure 4. TSLP exacerbates Th9 cell-mediated allergic inflammation.

(A) Naïve CD4⁺ T cells from DO11.10 mice were differentiated under Th2 and Th9 conditions with OVA_323–339 peptide and APC. Before transfer, IL-13⁺ and IL-9⁺ cells were measured in DO11.10 Th2 and Th9 cell cultures by intracellular cytokine staining following stimulation with PMA/Ionomycin.

(B) Concentration of accumulating IL-13 and IL-9 during Th2 and Th9 cell differentiation of DO11.10 T cells was detected using ELISA.

(C – G) Differentiated Th cells were injected to wild type recipients via tail vein, with PBS injection as control. Mice were analyzed after OVA or OVA+TSLP challenge for 5 days. After 5 days, recipient mice were analyzed for (C) BAL total cell and eosinophil counts, (D) percentage of IL-9⁺ and IL-13⁺ Th9 cells before transfer and in the BAL of recipient mice of Th9 cells, and (E) BAL cytokine concentration by ELISA. Lung pathology was examined by staining with (F) hematoxylin and eosin (H&E) and (G) Periodic acid-Schiff (PAS).

All data represent mean ± SEM (n=6–7 mice) and are representative of at least 2 experiments. *, p < 0.05.