WT WBCs only partially prevent the increase in CD18-deficient leukocytes that are neutrophils.

(A) To determine the percentage of WT or CD18-deficient leukocytes that were Gr-1⁺, blood leukocytes were stained and analyzed by flow cytometry as described in the text. The dot plot is an example of blood leukocytes derived from a CD45.1⁺ host that had received a 1:1 mixture of WT and CD18-deficient fetal liver cells 6 months previously. The plot shows the CD11a and Gr-1 staining profiles of CD45.2⁺ cells that fall within the forward- and side-scatter leukocyte gate. The percentage of cells that fall within each quadrant is shown. (B) The percentage of WT or CD18-deficient leukocytes that were neutrophils was determined by flow cytometry. WT and CD18 refer to WT or CD18-deficient leukocytes from host animals that had received either WT or CD18^−/− fetal liver cells alone. Mix-WT and Mix-CD18 refers to WT and CD18^−/−leukocyte populations, respectively, from animals that had received mixtures of both WT and CD18-deficient fetal liver cells. *, increase in the percentage of Mix-CD18 is significant (P < .05) compared with WT or Mix-WT. **, increase in CD18 is significant (P < .05) compared with WT, Mix-WT, and Mix-CD18.