Peripheral expansion in thymus-bearing hosts is down-regulated coincident with the appearance of recent thymic emigrants in the periphery.
Thymus-bearing (●) and thymectomized (□) C57BL/6 mice were lethally irradiated and given 10 × 106 Thy 1.2 T-cell–depleted BM cells and 5 × 105 Thy 1.1 congenic LN cells. Cohorts of 3 animals from each group were studied before BMT and at 3, 7, 14, 21, 28, and 35 days after BMT using flow cytometry to quantitate the absolute numbers of Thy 1.2+ (A) versus Thy 1.1+ (B) cells in the spleen. Statistical differences (P < .05) by Mann-Whitney test. SEs of the mean are shown by error bars. Statistically significant differences were observed at day 0, 3, 14, 21, 28, and 35 for Thy 1.2+ cell numbers and at day 7, 28, and 35 for Thy 1.1+ cell numbers.
