EpiScreen® 2.0 T Cell Epitope Mapping

In CD4+ T cell epitope mapping studies, 15mer peptides with a 12 amino acid overlap are synthesised spanning the test sample sequence. Individual peptides are then tested against PBMCs from 50 donors with >80% DRB1 allotypic coverage of the world population. Peptides may displace other peptides already bound to MHC class II or are taken up by antigen-presenting cells such as dendritic cells which process the peptides and present them in the form of linear peptides bound in the groove of MHC class II. Binding of the T cell receptor to these MHC class II/peptide complexes by CD4+ T cells can trigger an activation cascade causing T cell proliferation. T cell activation is determined by measuring T cell proliferation using EdU uptake.

Significant immunogenicity is determined through predetermined statistical assessment of the dataset using the T-test to provide details on magnitude of T cell response based on stimulation index normalization against background/vehicle control.

T cell epitopes are then identified by comparing overlapping immunogenic peptides to identify the core T cell epitope sequence.