Elimination of PLCγ2 partially abrogates E-selectin–mediated slow rolling and consequently reduces leukocyte adhesion in vivo. (A) Carotid cannulas were placed in chimeric mice reconstituted with bone marrow from Plcg2^−/− mice (n = 3) or WT mice (n = 3) and connected to autoperfused flow chambers. Average rolling velocity of neutrophils on E-selectin (left) and E-selectin and ICAM-1 (right) is presented as means ± SEM. The wall shear stress in all flow chamber experiments was 5 to 6 dyn/cm². (B) Mixed chimeric mice were generated by injecting bone marrow cells from LysM-GFP⁺ WT mice and Plcg2^−/− mice or Syk^−/− mice into lethally irradiated WT mice. Cumulative histogram of rolling velocities of 150 WT leukocytes (●), 150 Plcg2^−/− leukocytes (▾), and 150 Syk^−/− leukocytes (○) in inflamed cremaster muscle venules of mixed chimeric mice (n = 4) treated with PTx and a monoclonal blocking P-selectin antibody (RB40.34). Inset data are means ± SEM. (C) Numbers of adherent cells per square millimeter in murine cremaster muscle venules. Cremaster muscle exteriorized 2 hours after intrascrotal injection of 500 ng TNF-α in chimeric mice reconstituted with bone marrow from WT mice or Btk^−/− mice. Dotted line indicates the number of adherent cells in WT mice treated with PTx and monoclonal blocking E-selectin antibody (9A9). #P < .05.