FIGURE 1.

T cells accumulate in the thymus in the absence of CCR5. Thymi were harvested from WT and CCR5^−/− mice 5 to 6 wk in age and visualized using a compound microscope (A). Total number of thymocytes was enumerated (B), and the absolute number of CD4⁻CD8⁻ DN, CD4⁺ SP, CD8⁺ SP, and CD4⁺CD8⁺ DP cells (C) was characterized by flow cytometry. Data represent the mean ± SEM (n = 8–12) from two to three experiments. ^##p < 0.001.