Cbl-b deficiency stimulates the increased association of 14-3-3β with the β-chain of LFA-1 in BMDMs. (A) The association of β2-integrin (CD18) with 14-3-3β in BMDMs from WT and Cbl-b^−/− mice was studied. Immunoprecipitation of CD18 was performed in cell lysates of PMA-treated WT and Cbl-b^−/− BMDMs. The presence of immune complexes was determined by Western blot analysis for 14-3-3β (top panel). In addition, detection of CD18 by Western blot was also performed (bottom panel). (B) Expression levels of surface β2-integrin (CD18) and intracellular 14-3-3β (in fixed-permeabilized cells) were analyzed by FACS in WT and Cbl-b^−/− BMDMs. Nonspecific fluorescence was determined using secondary antibodies (dotted curves).