Figure 7.

CCR5 Expression Is Induced in Human Hematopoietic Stem/Progenitor Cells to Promote Cell Survival following Irradiation Injury

(A) CCR5 mRNA expression by RT-PCR of cord blood mononuclear cells at 4 and 24 h following either 150 or 300 cGy. Data are shown relative to 0 cGy for each time point. n = 3 per group. ^∗p = 0.03 and p = 0.002 for 150 and 300 cGy versus 0 cGy at 4 h, respectively. ^∗p = 0.0004 and p < 0.0001 for 150 and 300 cGy versus 0 cGy at 24 h, respectively.

(B) CCR5 mRNA expression of human bone marrow CD34⁺ cells at 24 h following irradiation. n = 3 per group. ^∗p = 0.003.

(C) CCR5 mRNA expression of human peripheral blood from healthy donors at 16 h following irradiation. n = 14–15 per group. ^∗p = 0.004, p = 0.008, and p = 0.001 for 100, 150, and 300 cGy versus 0 cGy, respectively.

(D) Representative flow cytometric analysis and quantification of CCR5 protein expression in human peripheral blood from healthy donors at 16 h following irradiation. n = 6–10 per group. ^∗p = 0.02 for 100 versus 0 cGy.

(E) CFCs from cord blood CD34⁺ cells following 7 days in culture with 30 ng/mL CCL5 + TSF compared with TSF alone. n = 3 per group. ^∗p = 0.007.

(F) Left, representative flow cytometric analysis of annexin V, 7-AAD stained human CD34⁺ bone marrow cells following 48 h in culture with 30 ng/mL CCL5 + TSF or TSF alone. Middle, levels of annexin V⁺, 7-AAD⁻ cells; right, levels of annexin V⁺ cells at 48 h following culture with specified conditions. n = 4 per group. ^∗p = 0.01 and p = 0.04, respectively. Data are shown as means ± SEM. Student's t test (two-tailed with unequal variance) was applied to the data.