Comparative analysis of thymocyte deletion in wild-type and CCR7-deficient mice after in vivo injection of anti-CD3 mAb. Nine-week-old C57BL/6 (+/+) and CCR7^−/− (−/−) mice were intravenously injected with increasing doses of anti-CD3 mAb. Forty-two hours after injection, thymocytes were recovered and stained as described for Figure 1. (A) Total number of thymocytes. (B) Total number of DP thymocytes. (C) Total number of CD4⁺CD8⁻CD24^high thymocytes. (D) Total number of lymphocytes isolated from peripheral lymph nodes in mice of both genotypes injected with PBS or different doses of anti-CD3 mAb, demonstrating a strong expansion of CCR7-deficient cells. Data shown was obtained from 12 mice of each genotype on C57BL/6 genetic background in 3 independent experiments. Similar results were also obtained for mutant mice on BALB/c background. Data has been subjected to 1-way ANOVA with Dunnett's multiple comparison post test. P values less than or equal to .05 were considered significant.