Figure 2. Selectin-null mice are defective in NK cell recruitment to tumors in Matrigel.

1×10⁴ LL/2 cells in 200μL of Matrigel were injected subcutaneously into the right flank of either C57BL/6 w.t. mice or C57BL/6 selectin-deficient mice. A. Tumors were dissected and weighed three weeks after injection. Results are expressed as box-whisker plots, the central line denoting the mean, the shaded gray boxes and the lines denoting the 90th, 75th, 25th, and 10th percentiles. B. Tumors were dissected over a 10-day period after injection, dissociated into a single-cell suspension, and analyzed by FACS for immune cell content. A plug of 200μL of Matrigel alone injected into the left flank of the same mice at the time of tumor injection was used as an internal control. Total leukocyte counts in the plugs of C57BL/6 control animals established that the tumor-specific immune response was particularly prominent on day 7 after tumor injection. C. At day 7 after tumor injection, NK cell recruitment to Matrigel containing LL/2 tumor cells, but not to Matrigel alone, was significantly reduced in L^-/- and ELP^-/- mice compared with C57BL/6 w.t. controls. NK cells were defined as NK1.1⁺, CD4 and CD8^- live leukocytes. Results are expressed as mean leukocyte counts obtained from 5-10 individual animals of each genotype, error bars = SEM.

*, p<0.005 by two-tailed Student’s t test.