FIG. 4.

FACS analysis of CXCR4 and CCR5 chemokine receptor expression on human lymphocytes recovered from uninfected hu-PBL-SCID mice. (A) Histograms represent percentages of CD4⁺ T cells positive for CCR5 (□) or CXCR4 (■) before hu-PBL injection in SCID mice (time 0) and in the peritoneal washings of hu-PBL-SCID mice 24 h and 1 week after the hu-PBL inoculation. Cells were stained with an anti-CD4 MAb and with either an anti-CCR5 or an anti-CXCR4 MAb; only CD4⁺ T cells were analyzed by flow cytometry. Percentages were calculated over the total number of CD4⁺ T cells. Values represent the mean ± standard error for 12 animals in three different experiments. (B) CXCR4 expression on human CD4⁺ T cells recovered from the peritoneal cavity of hu-PBL-SCID mice 24 h (shaded histograms) and 1 week (open histograms) postreconstitution. Four mice per group were analyzed in three different experiments. The figure shows the results of one representative experiment.