A. Colitis was induced by intravenous coinjection of CD4+CD25-CD62Lhigh T cells and congenically distinct (CD45.2) CD4+CD25high Treg cells into Rag2-/- mice (n=8/group; 1x106 and 2x105 cells per Rag2-/- recipient, respectively). Changes in body weight over time were monitored and are expressed as a percentage of the original weight. 