Whole blood (WB) samples collected from the animals on day 12 were incubated with WB assay buffer (nonphenol RPMI, 10 mM HEPES, and 0.5% FBS) and stimulated with 30 nM of SDF-1 (R&D Systems, Minneapolis, MN). Flow cytometry lysis buffer (FACS; BD Biosciences, Franklin Lakes, NJ), 1.6% EM grade formaldehyde, and water were added to fix and lyse the cells. The cells were centrifuged and washed two times with PBS, 2% FBS, and 0.2% sodium azide before addition of permeabilization/stain solution (1× HBSS, lysophosphatidyl choline, 4% formaldehyde, and FITC phalloidin (Phallicidin; Sigma-Aldrich, St. Louis, MO). The cells were then run on a flow cytometer (BD Biosciences). The lymphocyte population was gated, and median fluorescence was measured. For the leukocytosis assay, blood was added to a diluent (Isoton Diluent II; BD Biosciences), mixed, and lysed with 2 drops of lytic reagent (Zapoglobin II; BD Biosciences). WBC counts were measured with a cell counter (Coulter, Hialeah, FL). The mean ± SEM was calculated from results in three to four animals per group in both assays.