Mapping immunogenic DR15- and DQ6-associated PLP T-cell epitopes by immunization with individual overlapping peptides spanning hΔPLP. HLA-DRB1*1501-Tg, HLA-DQB1*0602-Tg and HLA-DRB1*1502-Tg (as control HLA-Tg line) mice were immunized (s.c.) each with an individual peptide (derived from native hPLP) of the overlapping peptides spanning hΔPLP. Ten days later, the primed LNC of immunized mice were analyzed ex-vivo for recall proliferative response to the immunizing peptide (0.5 - 5 μg/ml). Results expressed as stimulation index (S.I., mean cpm of antigen containing cultures/mean c.p.m of medium-containing cultures) are from one experiment with pooled draining LNC from two mice immunized with each individual peptide. Results are representative of three independent experiments.