Dominant high-frequency clonotypes are present in CD4⁺ T cell–mediated autoimmunity. Lethally irradiated Balb/c mice (n = 10) were transplanted with B6 BM and 0.4 × 10⁶ spleen cells. Animals were then euthanized 22 days after transplantation. CD4⁺ T cells (0.75 × 10⁶) were purified from pooled spleen cell suspensions and then injected intravenously into nonirradiated B6 Rag animals (n = 3). CDR3 region amino acid sequences derived from specified Vβ families are depicted for individual mice. Colors/patterns in stacked bar graphs denote individual animals.