Eosinophilic gastrointestinal disease and peanut allergy are alternatively associated with IL-5⁺ and IL-5⁻ T_H2 responses

Detection of food allergen–specific T-cell responses. A-D, Gating. CD4⁺ T-cell expression of CD154 and either IL-4 (E and G) or IL-5 (F and H) after incubation with peanut antigen (E and F) or media (G and H). In a separate experiment, peanut antigen–activated cultures were incubated with isotype control (I and J), or anti-MHC class II mAb (K and L), n = 5. SSC, Side scatter; FSC, foward scatter.

AEG is associated with a greater frequency of peanut-specific IL-5–producing T cells. The frequency of (A) IL-4, (B) IL-5, (C) IFN-γ, and (D) TNF-expressing peanut antigen–specific CD4 cells was determined for each subject group. Each symbol represents an individual subject. The median value is denoted by a horizontal bar. Intergroup statistics are shown over the brackets. NA, Nonatopic.

Food-specific T cells exhibit complex cytokine coexpression patterns. Cytokine coexpression by peanut-specific T cells from subjects with AEG (A, C-E) or PA (B). F, Each of the 15 possible cytokine combinations is shown as a proportion of the total peanut response. Individual subjects and medians are denoted by dots and horizontal bars, respectively. All subjects from the 3 groups were studied. ^∗P ≤ .05; ^∗∗P ≤ .01; ^∗∗∗P ≤ .001. NA, Nonatopic.

AEG is singularly associated with food allergen–specific IL-5⁺ T_H2 cells. A-D, The frequency of food antigen (Ag)–specific CD4 cells for each cytokine subpopulation and subject group. E-H, Stack graphs depict the median values for each cytokine subpopulation summed to represent the total frequency of Ag-specific cytokine-producing cells. NA, Nonatopic; SEB, staphylococcal enterotoxin B.

Correlation of T_H2 responses with IgE and eosinophilia. A, Correlation of IL-5⁺ T_H2 cells with eosinophil count. Correlation of peanut-specific IgE with IL-5^– T_H2 (B) and IL-5⁺ T_H2 (C) cells. D, Correlation of soy-specific IgE with IL-5^– T_H2 cells. Linear regression curve fit is shown for subjects with AEG (A) and PA (B and C). SEB, Staphylococcal enterotoxin B. ^∗P < .05.

Peanut antigen–specific CD4 T-cell cytokine responses. PBMCs from all 4 subject groups were incubated with either media or peanut antigen for 6 hours, and the frequency of CD154⁺, cytokine-producing cells was determined by flow cytometry. Each symbol represents a subject with AEG. Red symbols and lines denote the 2 subjects with AEG treated with prednisone. The bracketed numbers at the base of some plots denote the number of overlapping 0 value results. NA, Nonatopic.

Ratiometric analysis of peanut antigen–specific cells. The frequency of antigen-specific cytokine-producing cells as shown in Fig 2 was used to calculate IL-4:IFN-γ (A) and IL-5:IFN-γ (B) ratios for each subject. Each symbol represents a unique subject. NA, Nonatopic.

AEG is singularly associated with food allergen–specific IL-5⁺ T_H2 cells. Pie graphs represent the proportional contribution of each cytokine subpopulation to the total antigen-specific response. Each pie corresponds to the same lettered stack graph in Fig 4, E-H. NA, Nonatopic; SEB, Staphylococcal enterotoxin B.

Correlation of IL-5⁺ T_H2 cells to tissue and blood eosinophilia. A-C, The correlation between food antigen (Ag)–specific IL-5⁺ T_H2 cells and blood eosinophil count. D-G, The correlation between staphylococcal enterotoxin B–specific IL-5⁺ T_H2 cells and gut tissue eosinophilia. Gut tissue eosinophilia was measured as the upper quartile count of eosinophils (eos)/high power field.