Figure 3.

Analysis of canine FIX (cFIX) peptide pools which showed reactivity in the IL-10 ELISpots. (a) A peptide library of 89 peptides spanning the sequence of cFIX was organized into a matrix in which each peptide was represented in two orthogonal pools. Highlighted in grey are the pools that scored positive in most of the dogs analyzed. Positivity in two orthogonal pools identified a single stimulatory peptide, peptide 68. Peptide 68 amino acid sequence is indicated. (b) Peptides contained in pool 4 were rearranged into a smaller orthogonal matrix, allowing the identification of another reactive peptide that spanned the Chapel Hill mutation (peptide 84). *Chapel Hill mutation (glycin→glutamic acid) within peptide 84. (c) IL-10 secretion detected by ELISpot in PBMCs obtained form H24 (group C, ATVRX, 8.5 × 10¹² vg/kg with IS) stimulated with the matrix represented in b. ELISpot, enzyme-linked immunosorbent assay; IL, interleukin; PBMC, peripheral blood mononuclear cell.