Figure 2
Interleukin (IL)-4Rα-driven effects exacerbate anaphylaxis. (a) Il4rαF709 mice show an increased loss of temperature and limited recovery from anaphylaxis. Wild-type and Il4rαF709 mice lacking endogenous immunoglobulin E (IgE; IgE−/−) were subjected to IgE-mediated passive anaphylaxis, and core body temperatures were recorded to assess the severity of the response. Statistical analysis by two-way analysis of variance (ANOVA). (b) Il4rαF709 mice uniquely exhibit rapid-onset diarrhea during IgE-mediated passive anaphylaxis. P=0.0084 by log-rank test of Kaplan–Meier survival curves. (c) Serum release of mouse mast cell protease (MMCP-1) is greatly enhanced in Il4rαF709 mice following passive anaphylaxis. Statistical analysis by one-way ANOVA. (d) IL-4 release in Il4rαF709 mice is also enhanced following passive anaphylaxis. Statistical analysis by unpaired t test. Mice were injected retro-orbital (RO) with 20 μg IgE anti-DNP (anti-2,4-dinitrophenol; clone SPE-7) and challenged 16 h later with 0.5 mg DNP-BSA (bovine serum albumin) RO Data shown are from 4–7 mice per group and are representative of three experiments. *P<0.05, **P<0.01, ***P<0.0001 by Bonferroni post-test where indicated. Enhanced anaphylaxis in Il4rαF709 mice is not the result of altered vascular responsiveness. Wild-type and Il4rαF709 mice were injected RO with (e) histamine (1.25 mg), (f) serotonin (1 mg), or (g) leukotriene C4 (LTC4, 1 μg), and core body temperatures were recorded to assess the severity of the response. Data shown are from 3–5 mice per group.
