GVHD-associated autoimmunity is due to antigen-driven expansion. (A) Lethally irradiated Balb/c mice (n = 7) were transplanted with B6 BM and spleen cells to induce GVHD. Animals were then euthanized 18 days after transplantation and pooled spleen cell suspensions adjusted to yield a T-cell dose of 0.5 × 106 were injected intravenously into nonirradiated B6 Rag animals. After 60 days, animals were euthanized and TCRβ spectratype and clonotype analysis was performed on processed colon tissue from each individual mouse. The name and number of CDR3 region amino acid sequences derived from dominant peaks in specified Vβ families is depicted. Colors/patterns in bar graphs represent individual mice. Clonotypes in bold denote shared clonotypes between multiple animals. (B) Venn diagram showing the distribution of unique and overlapping clonotypes derived from the input splenic T-cell population and the colons of animals that received the transferred T cells. (C) Table denoting the 6 most frequent clonotypes in the colon that were shared between multiple mice. The number of sequences in the spleen and colon and the percentage of total sequences within a given Vβ family that these sequences represented are depicted.
