Congenically-marked, CFSE-labeled WT (45.1) and CD11a−/− (45.2) CD4+ T-cells were co-injected (iv; 107 cells each) into RAG-1−/− recipients. At 7 days following T-cell transfer, animals were sacrificed, T-cells were isolated from the spleen, stained for CD4, CD45.1 and CD45.2 and analyzed by flow cytometry. (A) T-cell numbers within the spleen. (B) Quantification of CFSE fluorescence in WT and CD11a−/− T-cells. Insert shows representative histogram of CFSE fluorescence for each T-cell population. Data represent the mean±SEM for N=6 mice per group and *p<0.05 vs. WT T-cells.