Abstract
Background: The contribution of phenotypic variation of peanut-specific T cells to clinical allergy or tolerance to peanut is not well understood. Objectives: Our objective was to comprehensively phenotype peanut-specific T cells in the peripheral blood of subjects with and without peanut allergy (PA). Methods: We obtained samples from patients with PA, including a cohort undergoing baseline peanut challenges for an immunotherapy trial (Consortium of Food Allergy Research [CoFAR] 6). Subjects were confirmed as having PA, or if they passed a 1-g peanut challenge, they were termed high-threshold subjects. Healthy control (HC) subjects were also recruited. Peanut-responsive T cells were identified based on CD154 expression after 6 to 18 hours of stimulation with peanut extract. Cells were analyzed by using flow cytometry and single-cell RNA sequencing. Results: Patients with PA had tissue- and follicle-homing peanut-responsive CD4 + T cells with a heterogeneous pattern of T H 2 differentiation, whereas control subjects had undetectable T-cell responses to peanut. The PA group had a delayed and IL-2–dependent upregulation of CD154 on cells expressing regulatory T (Treg) cell markers, which was absent in HC or high-threshold subjects. Depletion of Treg cells enhanced cytokine production in HC subjects and patients with PA in vitro, but cytokines associated with highly differentiated T H 2 cells were more resistant to Treg cell suppression in patients with PA. Analysis of gene expression by means of single-cell RNA sequencing identified T cells with highly correlated expression of IL4, IL5, IL9, IL13, and the IL-25 receptor IL17RB. Conclusions: These results demonstrate the presence of highly differentiated T H 2 cells producing T H 2-associated cytokines with functions beyond IgE class-switching in patients with PA. A multifunctional T H 2 response was more evident than a Treg cell deficit among peanut-responsive T cells.
Original language | English |
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Pages (from-to) | 2107-2120 |
Number of pages | 14 |
Journal | Journal of Allergy and Clinical Immunology |
Volume | 141 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2018 |
Keywords
- Food allergy
- T 2
- peanut allergy
- regulatory T
- tolerance