Figure 4.

SWAP70 Regulates Phagocytosis and Phagosomal F-Actin

(A) Knockdown of dendritic cells with control (black, siControl) or SWAP70 siRNA (orange, siSWAP70) quantified by western blot (mean ± SEM). GAPDH, loading control.

(B) Dendritic cells with siSWAP70 were pulsed with FITC-labeled zymosan. Zymosan-positive cells were quantified by FACS after 30 and 60 min for at least four donors. See also Figures S5A and S5B.

(C) The total zymosan-FITC signal for the zymosan-positive cells from (B). MFI, mean fluorescence intensity. See also Figures S5C and S5D.

(D) Confocal micrographs of FITC-labeled zymosan (red) pulsed dendritic cells with siControl (left) or siSWAP70 (right). F-actin was stained with phalloidin (cyan). Yellow arrowheads, F-actin positive phagosomes. Scale bar, 20 μm.

(E) Quantification of phagocytosis from (D) (mean ± SEM; >40 cells/donor/condition).

(F) Rescue experiment of phagocytosis for dendritic cells with siSWAP70 and SWAP70-GFP (individual donors shown). See also Figures S5E and S5F.

(G) The MFI of phalloidin labeling in the zymosan-positive and -negative populations of cells from (B).

(H) Percentage of phalloidin-positive phagosomes from (D).

(I) Quantification of the phalloidin signals of F-actin-positive phagosomes from (D).

See also Figures S5G, S5H, and S6.