Background: Identification of potential T-cell epitopes in the
peanut major allergens is essential for development of peptidebased
immunotherapy. Traditional methods of T-cell epitope
discovery use overlapping short peptides spanning the full
length of the protein in T-cell proliferation assays. Because large
proteins, such as Ara h 1, require a large number of peptides,
this limits screening to a small number of allergic subject–
derived T-cell lines.
Objective: We sought to identify candidate peptides of Ara h 1
that display promiscuous binding to MHC class II and induce
TH2 cytokine production by T cells.
Methods: In silicoMHCclass II binding predictionwas performed
with NetMHCIIpan 2.0 (peptide length, 15; 1-mer offset) and the
most abundant class II alleles in the North American population
andwith an in vitroMHCclass II peptide reporter assay performed
in parallel, which used synthetic 15-mer peptides offset by 5 mer
spanning the protein.High-resolutionMHCclass II typing and aTcell
proliferation assay using preselected peptides were performed
with PBMCs from 98 subjects with peanut allergy and 14 healthy
control subjects. IL-4, IL-13, IL-5, IFN-g, and TNF-a levels were
measured in culture supernatants.