Fig. 1.

Expansion of T cells to low-stability peptide:class II complexes is lost in the presence of ongoing responses to unrelated peptide antigens. (A) Mice were immunized in the hind footpad with 25 nmol of HEL[11-25] in an emulsion containing IFA/PBS and 0.6 μg/mL LPS either alone (○) or in a mixture containing 5 nmol of each of the dominant peptides LACK[156-173], HA V1, and MalE[69-84] (●). (B–E) Mice were immunized with 25 nmol of OVA[327-339], or 5 nmol of higher-stability variants, OVA V1, OVA V2, and OVA V3 alone (○) or in a mixture containing dominant peptides (●). Draining LNs from individual mice were pooled, n = 2 mice per group. Shown is the total number of IL-2 secreting antigen-specific cells at day 10 after restimulation with increasing doses of the test peptides or 5 μM of competing dominant peptides (Right in A–E). The results are representative of 2–7 independent experiments.