Figure 5
Interleukin (IL)-4Rα signaling directly promotes mast cell expansion during food allergy in vivo. (a) Experimental design: mesenteric lymph node (MLN) cells from ovalbumin (OVA)-sensitized Il4rαF709 mice were adoptively transferred into naive recipient mice. The recipients were radiation bone marrow chimeras, previously reconstituted with a mixture (50:50) of bone marrow from wild-type and either Il4rαF709 or IL-4Rα−/− animals. They were then fed OVA over 10 days to drive mast cell expansion. Cells from saline-treated Il4rαF709 mice were separately transferred into control recipients. Intestinal mast cells were analyzed using flow cytometry. (b) IL-4Rα is required for maximal mast cell expansion. Adoptive transfer of OVA-allergic cells into wild-type/IL-4Rα−/− mixed bone marrow chimeras (n=4–5 per group) favors the outgrowth of IL-4Rα-sufficient mast cells. (c) Expression of an activated IL-4Rα variant promotes mast cell expansion in a cell-intrinsic manner in wild-type/Il4rαF709 mixed bone marrow chimera recipients (n=6 per group). Statistical analysis by repeated measures two-way analysis of variance with Bonferroni post-tests for b and c, *P<0.05, ***P<0.0001.
