FIGURE 3.

Stable overexpression of uPAR in HEK293 cells accelerates corpse uptake. a, electron micrograph of HEK293 cell, a non-professional phagocyte engulfing apoptotic bodies indicated by arrowheads in respective panels. i, filopodial extensions and formation of phagocytic cup around an apoptotic body; ii and iii, presence of multiple apoptotic bodies within HEK293 cell; iv, a phagocytic portal engulfing multiple apoptotic blebs. b, HEK293 and HEK293-uPAR cells were labeled with membrane labeling dye PKH67 and co-cultured with the phagocytes at a ratio of 1:10. As cells were harvested by trypsinization, the above data represents mostly internalization. c, surface uPAR expression in HEK293-uPAR stable cells was confirmed by rabbit polyclonal (399R) antibody staining of live cells. d, cell surface expression of functional αvβ5 heterodimers in HEK293 and HEK293-uPAR cells was analyzed by monoclonal P1F6 antibody that recognizes a shared epitope in the heterodimer. e, Western blot analysis following extraction in SDS-containing radioimmune precipitation buffer. Asterisk, p < 0.05.