Fig. 4

AKT2 deficiency leads to the defect of actin polymerization during BCR activation. TIRFm is used to detect the actin polymerization, the recruitment of phosphorated CD19 (pCD19) and phosphorated WASP (pWASP) in the contact zone of B cells during early B cell activation. Spleen cells from WT and AKT2 KO mice (n = 3) were incubated with AF546-mB-Fab’-anti-Ig tethered to lipid bilayers, following stimulated at 37 °C for varying length of times. After fixed and permeabilized, cells were stained with AF488-phalloidin for actin, anti-pCD19 and pWASP antibodies. Representative images of TIRFm were shown (a, b, e, f). The MFI of pCD19, actin and pWASP were analyzed by TRIFm (c, d, g), and data are generated from more than 50 cells from 3 individual experiments and presented as average value ± SEM, Scale bars, 2.5 μm. *p < 0.05